SNAKE-BITE In the British Isles, and throughout the greater part of North - Western Europe, this subject is of theoretical rather than of practical interest, except in certain localized districts particularly infested with vipers, but it attains very considerable importance in tropical and sub-tropical countries.
In such warmer countries, snake-bite may be the actual cause of many deaths and cases of serious illness among domesticated animals; and, on the other hand, it is apt to be assumed as the cause of all suddenly arising local swellings; cases of snake-bite may therefore be confused with cases of such a disease as anthrax.
The relative frequency with which cases are encountered in the various species of domestic ated animals will naturally depend to some extent on the relative numbers of the animals present, and on the conditions under which they are kept, and will therefore show some variation in different countries and districts, but, generally speaking, the dog is the species most frequently affected, and sporting dogs probably suffer to the greatest extent. Cases of snake-bite are commoner in cattle than in horses, and sheep are not infrequently attacked. Cats are very much less frequently affected than dogs, although some cats are expert and keen destroyers of snakes; the cat probably owes its relative safety to its rapidity of movement combined with great caution.
Pigs are also quite rarely affected, and devour snakes very readily, so that it is said to be a practice in some parts of the Mississippi area to turn, pigs on to low marshy ground known to be badly infested with young rattle-snakes. The pig is certainly more resistant to snake venom than a number of other species, such as dogs, cats, or donkeys, but there is no true immunity, and the rarity of cases of snake-bite in pigs is probably due principally to the mechanical protection afforded by the thick subcutaneous layer of adipose tissue.
It is of interest to note that the Indian mongoose is very resistant to the action of venom, but here again it is rather its rapidity of movement which enables this animal to attack and kill venomous snakes almost with impunity.
Classification. It is not proposed here to give more than a very rough outline of this subject, but a certain superficial knowledge of the classification of snakes is always of interest, and may be of considerable utility, to the practitioner in warm climates.
In the first place, it cannot be too strongly emphasized that size, colour, and skin markings are by no means always reliable guides to the nature of a snake; in many cases observations restricted to these details lead to most erroneous ideas. As regards size, it is obvious that all snakes are at first of very small size, and only attain their maximum length after a consider able period of more or less steady growth. With respect to colour, individuals of the same species may show very great differences, and considerable changes may be observed during the life of one individual; similarly, skin markings may vary considerably in different individuals of one species, or even in one indivi dual at different periods of its life.
In some cases certain peculiarities of form, size, colour, or habit are so striking that there is little or no chance of their passing unobserved or being misinterpreted. Thus a snake which, when enraged, flattens the ribs in the cervical region so as to form a distinct" hood, " may safely be identified as belonging either to the genus Naia (the Cobra genus) or to the genus Sepedon (African Ringhals or spitting snake, closely allied to the Cobras), and is to be regarded as venomous. Again the puff adder of Africa (and Arabia) is easily recognizable on account of its distinctive size, form, colour, and skin markings, as in this case the variations observed are not sufficient to mask the identity of the snake to the observer of ordinary African experience. On the other hand, a cobra which fails, while under observation, to expand the hood may not be recognized as such, while the harmless mole snake is very frequently mistaken for a cobra; similarly, the perfectly harmless egg-eating snake (Dasypeltie ecabra) is very often thought to be a night adder, as there is some resemblance in size, colour, and markings. Such confusion may lead to much unnecessary alarm amongst human beings, or possibly in some cases to a dangerous lack of precaution; on the other hand, from this cause some line of treatment adopted for a bite may gain a totally undeserved reputation.
It is very desirable for any veterinary prac titioner residing in a snake-infested district to learn to recognize most of the species present, and this he can do by a little careful study of killed specimens, but it is important from the first to distinguish between venomous and non venomous snakes. For this purpose it is only necessary to examine the dentition of the upper jaw.
Ordinary non-venomous snakes show two long rows of teeth on each side of the upper jaw, an outer maxillary and an inner palatine row, numbering about 35 and 20 teeth re spectively. These teeth, which are small and curved backwards, are all solid and show no very striking variations in In the upper jaw of a venomous snake, such as a cobra or an adder, the palatine teeth are very similar, but the outer maxillary row is represented on each side by a single tooth or fang, which relatively is very large, is situated near the anterior extremity of the maxilla, and which is more or less covered by a loose fold of mucous membrane. This membranous fold contains a series of very small fangs in different stages of development, so that a fang which is broken of or shed is replaced by the first (and furthest developed) of the replacing fangs. The fang is deeply grooved in snakes of the cobra type, whereas in vipers or adders the fang, which is very long and sharply pointed, is pierced throughout its length by a central channel. The channel or groove communicates at the base of the tooth with the duct leading from the poison gland, which is situated behind the eyes, and can be violently compressed by contraction of the masseter muscle.
From the foregoing description it will be realized that a bite inflicted by a non-venomous snake will generally produce two double rows of numerous small punctures, whereas that of a venomous snake will cause two single rows of such small punctures, and one relatively large and deep puncture on each side, external to these single rows. These details are some times observable in human beings and in animals where the skin is hairless or shaved.
Finally, it may be remarked that there is an intermediate group of snakes, known as the Opisthoglypha, in which certain teeth situated towards the centre' of the maxillary row are of larger size and grooved. These snakes have generally been held to be only very slightly venomous, but we have been able to show that one member of this group (Dispholidue typus, the South African" Boomslang") is, under conditions favourable to the snake, able to inflict bites fatal to horses, mules, baboons, and sheep.
Period of Incubation. With respect to the period of incubation, symptoms may be shown within five or ten minutes of the, bite, while in other cases no evidence of systemic disturb ance may be noticeable for some hours, and even for a day or longer.
Local swelling, in those cases in which a swelling forms, may also be noticeable within five or ten minutes of the infliction of the bite, or it may often take some hours to become sufficiently large to attract notice, In considering the effects produced on animals by snake venom, it is most important to realize that the nature and severity of the symptoms depend not only on the species of snake con cerned, but also on the dose of venom actually injected into the wound and absorbed into the circulation, and this dose is liable to great variations under the influence of a number of different factors.
In the first place, the age and size of a snake will naturally bear some relation to the size of the poison glands and to the amount of venom which can be secreted and accumulated. In this connection, however, we have shown that young" Ringhals" snakes, when less than twenty-four hours old, are able to inflict a bite fatal to the guinea-pig, while a Ringhals aged one month, and rather less than 6 inches in length, was able to kill a large Irish terrier, so that a young and small snake may be able to secrete more than a lethal dose of venom.
More important factors are the time which has elapsed since the last occasion on which a bite was inflicted or prey was ingested, and the nature and depth of the actual lesions produced by the fangs in biting. The bite of a snake is naturally less dangerous very soon after the reptile has bitten some other object, and if the bite is inflicted through clothing, or thick hair or wool, or if the fangs are not driven directly into the flesh, a large proportion of the venom may fail to be injected subcutaneously, and therefore will not exercise any action on the bitten organism.
There are certain snakes (Sepedon hcema °hates, the Ringhals of Africa) which, in addition to biting, have also the ability to project venom into the eyes of their prey or enemies. This is brought about by violent contraction of the masseter muscles attached to the capsules of the poison glands, the head being and the mouth opened, and these snakes show great skill in directing the flow of venom at the opponent's eyes. In this way venom can be projected for a distance of at least 6 feet.
Apart from the variations due to the above mentioned causes, it is necessary to recognize two distinct groups of cases arising from the action of colubrine (cobra type) and viperine (adder type) venoms respectively.
There are a number of symptoms common to both types of cases, and in some cases it might be difficult to determine, from clinical symptoms alone, the nature of the venom injected.
Generally speaking, however, colubrine venom exerts its chief and most noticeable action on the nervous system, and particularly on the mechanism governing respiratory movements, while in cases due to viperine venom the local action is very well marked. It is therefore convenient to describe the two types of cases separately.
A. Symptoms shown by Animals bitten by the Cobra Type of Snake. The general course may be summarized thus: (a) In the majority of cases there is a period of excitement and restlessness, which may last for a few minutes only, or may persist for an hour or longer, especially in those cases in which local pain is noticeable.
(b) The preliminary excitement may be suc ceeded by a period during which the animal appears normal.
(c) Later, in the majority of cases (but not in all), there are symptoms of nervous excite ment. Within one to two hours (or in larger animals within four or five hours) of the bite the animal may show convulsive muscular contractions, and may within a short period die of asphyxia. This is seen particularly in sheep and dogs, but may occur in the larger domestic species.
(d) Animals not succumbing early from asphyxia generally develop symptoms of general depression, sometimes interrupted by periods of restlessness and excitement. As a rule, in cases surviving for a long time there is a final stage of dulness and depression, which persists until death occurs, or until there are general signs of recovery.
These various phases occur in the majority of cases, but the duration and intensity of any one stage is liable to very wide variation; thus in some cases of cobra-bite symptoms of nervous excitement are very well marked, while in other cases such symptoms are almost or completely lacking, and symptoms of depression predominate.
In many cases no evidence of pain is shown, while in other cases many symptoms of local pain are observed. Such symptoms include extreme restlessness, repeatedly lying down and rising again, sweating, hurried respiration, and a frequent hard pulse. There may also be symptoms of local pain especially associated with the particular area involved, such as lame ness, abnormal gait or posture.
Symptoms of nervous excitement, apart from manifestations of pain, include restless move ments of the head, limbs, or tail, restless wandering about the box or stall, grinding of the teeth, salivation, frequent movements of deglutition, and frequent defa3cation and micturition. Animals may also show such signs of cerebral disturbance as licking walls, biting the air, and knocking the head against the wall or manger. During this stage of excitability the animal generally shows fre quent deep respirations and a frequent fast pulse.
quivering of muscles, or even strong spas modic contractions, may be seen, and in each case the process may be local or more or less general. Immediately before death there may be asphyxial convulsions.
A number of the above-mentioned symptoms may arise from pain, and in some cases it is difficult to determine whether the symptoms are due to pain or not.
Under the heading of symptoms of" Nervous Depression" one may include a group of symptoms varying from slight dulness to paresis, either local or more or less general, and even paralysis. In the dull stage the animal is inclined to remain for long periods in one position; the head hangs, the ears droop, and frequently the eyes are closed. Later the animal may go down, or it may rest against a wall. Co-ordination of movement may become impaired, resulting in a staggering gait, and loss of control over particular parts may be noticeable. Thus the lower lip may fall away from the teeth, and the lips are then unable to close on any food, although an effort may be made; the anus may be relaxed, and in equines the animal may be unable to pro trude the penis in micturition, or to retract it when protruded. Animals in this stage some times show well-marked salivation.
The corneal reflex is generally obtained until very shortly before death, but where symptoms of paresis or Moo-ordination are shown, the reflex may be delayed or slow.
General dulness and depression are usually seen in animals that eventually recover, although such a stage also occurs in many fatal Animals showing symptoms of inco-ordma tion, loss of control, or paralysis in our own cases have always later become comatose and died.
The temperature is not noticeably affected.
In rapidly fatal cases no local swelling is seen, but a noticeable swelling is present in many other cases, and particularly in cases which survive for many hours, or even days, and in those which end in recovery. Consequently, such swellings are more common in the larger animals and in those smaller animals which have received less than the lethal dose of venom. The swellings vary greatly in size and extent, and also in character. In some cases the local lesion is soft and insensitive, and it is then frequently pendulous, while in other cases it is hard or tense, warm to the touch, and very sensitive to manipulation; the larger swellings are generally soft and insensitive. These swellings show a great tendency to gravi tation, and may therefore be most prominent in regions situated at some considerable distance from the lesions inflicted by the fangs. In cases of recovery the swelling may persist for a week or longer, but it has usually disappeared at the end of two weeks.
Death generally occurs through stoppage of the respiratory movements, and the heart may continue to beat for three or four minutes after all signs of respiration have ceased.
Duration. In equines death frequently occurs on the second day after the bite, and the most rapidly fatal case we have seen was that of a mule (bitten by the yellow or Cape cobra), which died in slightly over five hours.
Sheep and dogs frequently succumb within two hours, and even in considerably less than one hour, but death may not occur until the tenth hour or later.
B. Symptoms due to the Bite of the Adder Type of Snake. The general course of the attack shows some resemblance to that seen as a result of a cobra-bite, the following stages being noticeable: (a) A period of restlessness and excitement, which appears to be due chiefly, if not entirely, to local pain.
(b) In some cases the first stage is succeeded by a period during which the animal shows little abnormality, apart from the presence of a local lesion, which is generally large, and increases rapidly in size.
In most cases, however, signs of pain are very noticeable at frequent intervals or almost continuously.
(c) In a few cases dyspnea sets in early— after an hour or less in dogs and sheep, or a few hours in the larger animals. In such cases the animal dies within a short period, after showing muscular tremors and contractions, or even marked convulsions, followed quickly by depression, coma, and death.
(d) Animals surviving for longer periods pass through a final, and often prolonged, stage of depression, which may end in recovery or death.
These cases generally differ from the majority of those due to the cobra type of venom, in that a local swelling is a prominent feature, and that there are generally obvious signs of acute local pain.
Livid discoloration of the skin around the punctures caused by the fangs is common, although it may not be easily perceived, on account of a thick growth of hair and cutaneous pigmentation; such a lesion may also occur after cobra-bites, but with viperine venom the effect is more marked.
In animals which succumb rapidly, as a result of the early onset of dyspnea, the local swelling may not be very noticeable, but in the great majority of cases it is large and prominent, and it may be enormous. Some swelling is usually noticeable within a quarter of an hour, in the form of a more or less circular elevated area of skin, over and around the punctures. At first the swelling is rather soft, but it rapidly becomes tense, warm to the touch, and very sensitive to palpation. In most cases it increases rapidly in size and shows a well-marked tendency to gravitation. In cases ending in recovery the swelling later becomes softer and less sensitive, and it decreases in size rather slowly.
Local pain is generally present in a very much greater degree than is seen in cases due to the bite of the cobra type of snake. The usual symptoms are great restlessness and excitement, grinding of the teeth, profuse sweating, frequent micturition and defaecation, hurried respiration, and a frequent hard pulse. Owing to the usual occurrence of much local pain and swelling, there are generally pronounced symptoms associated with the particular area affected by the bite; thus if one of the limbs has been bitten, there is generally well-marked lameness, and the affected limb may be carried or rested, or it may be moved restlessly from time to time.
We have never observed any signs of inco ordination, paresis, or paralysis as a result of a viperine bite, nor such cerebral symptoms as licking walls or biting at the air.
In those cases in which dyspnea sets in early and the animal dies of asphyxia there may be twitching of various groups of muscles, and later strong muscular contractions and involun tary defecation.
After the more painful phase has passed, or during apparent intervals of relief from the pain, the animal is usually dull and depressed, standing for a considerable time in the same position, with hanging head, drooping ears, and frequently with the eyes closed. The pulse becomes infrequent and weak and the respira tion laboured.
At a later stage the animal shows increasing weakness, sometimes swaying from side to side, and then lies down; in some cases the neck is stretched and the muzzle rested on the ground.
In fatal cases the weakness increases, the pulse and respiration become progressively weaker and less frequent, and the conjunctival reflex slower and delayed. Finally the animal lies in a comatose condition, insensitive to various stimuli, with stertorous respiration and a weak infrequent pulse until death occurs.
Post - mortem Lesions. A. Lesions due to Colubrine Venom (Cobra Type). There is generally a local lesion, although this may be very small and not associated with any definite swelling. The lesion usually takes the form of an infiltration of the subcutaneous areolar tissue with a yellowish serous liquid, but sometimes it is hmorrhagic in parts, and exceptionally there may be extensive hmorrhagic infiltra tion. The liver generally presents the changes associated with fatty degeneration, and some pulmonary oedema is often to be noted. Pete chim or ecchymoses are often present under the epicardium and endocardium, and may be observed in the trachea, under the pleura, and in the stomach and intestines; in the intestinal tract there may be hyperaemic areas, swelling of Peyer's patches, or hmorrhagic streaks and patches. The blood as a rule is not obviously affected, although most colubrine venoms have been shown to possess anti-coagulative and hmmolytic properties in vitro.
B. Lesions due to Viperine Venom. On reflecting the skin over the local lesion, livid areas may be seen around the punctures. There is generally an extensive infiltration of the sub cutaneous areolar tissue, and the deep fascia, and even the subjacent muscular tissue, are commonly involved. The oedematous liquid is of a deep red colour, and a gelatinous material, also deeply blood-stained, may also be present. The hmorrhagic area may be surrounded by a zone infiltrated with a clear yellowish liquid. The liver and kidneys generally show signs of fatty degeneration, and petechiae and ecchy moses are found in similar situations to those mentioned in connection with cobra-bites, but those resulting from viperine bites are generally more numerous and extensive. With regard to the action on the blood, most viper or adder venoms have a considerable coagulative effect, but certain venoms of this group exert a distinct anti-coagulative action in vitro, and even in vivo.
In discussing the post-mortem lesions, it is of interest to note here the effect of the venom of Dispholidus typos, the South African" Boom slang." This species, which belongs to the group of Opisthoglypha, has generally been con sidered to be more or less harmless to the larger mammals, but we have succeeded in causing this snake to inflict bites fatal to horses, mules, sheep, etc.
The symptoms, apart from some excitement in certain cases, were those of rapidly developing anemia and exhaustion produced by internal haemorrhage, occurring after a very long period of incubation.
On post-mortem examination numerous and extensive haemorrhages were found. In some cases these were all subcutaneous, reflection of the skin revealing a number of well-defined hmorrhagic patches scattered irregularly about the trunk, limbs, and head and neck. In other cases haemorrhage occurred into the respiratory passages, the serous cavities, or the gastro intestinal canal, and smaller haemorrhages in the depth of solid organs were also seen.
Diagnosis. During Life. In practice it is only occasionally that the actual bite is wit nessed, as regards horses, cattle, and sheep, these animals generally receiving the bite when out grazing. The infliction of the bite is more often witnessed in dogs, particularly in sporting dogs, but even in these animals the occurrence of snake-bite may only be surmised by the owner.
When the animal is seen very soon after the bite, the state of excitement may be suggestive, and signs of local pain or irritation may lead to the discovery of the punctures inflicted by the fangs; these punctures may then be bleeding.
At a later stage the formation of a local swelling may attract the attention, and the fang punctures may be discovered. In tropical regions where snakes are common the layman is very apt to ascribe all swellings in animals to the effect of snake-bite, but in many of these regions both anthrax and blackquarter are very prevalent.
The swelling in snake-bite has not the dis tinctive characters found in a case of black quarter, and in most cases there should be no difficulty in differentiating them.
A swelling due to snake-bite may resemble considerably some of the swellings seen in cases of anthrax, but in the former case the tempera ture remains more or less normal, and very often there are general symptoms which are not seen in anthrax.
At certain stages of pain and nervous excite ment the case may show some resemblance to one of acute spasmodic colic, but the cases associated with the greatest pain, i.e. those due to viperine venom, are usually associated with the formation of a prominent local lesion, and there are often obvious signs that the seat of the pain is not abdominal.
In most cases due to colubrine venom the pain is apparently not severe, and there are usually some nervous symptoms not commonly associated with spasmodic colic.
The occurrence of severe pain in a horse, associated with the presence of a warm, tense, and painful swelling, may arouse suspicion of the" colicky" form of anthrax, but in snake bite, as stated before, the temperature is little, if at all, raised.
Post-mortem. In making an autopsy in a suspected case of snake-bite, one will naturally pay particular attention to the local lesion, if any be noticeable, and in all such cases one should examine the reflected skin carefully for signs of the punctures made by the fangs.
Apart from the occurrence of cutaneous punctures and the characters of the local oedema (if present), there are usually no very obvious macroscopic changes on which to base a diagnosis. In most cases, however, the history of the case is very helpful, and such diseases as anthrax, if suggested as possible causes, can be excluded by microscopical examination and, if necessary, by determining the absence of the distinctive lesions.
Treatment. (1) When procurable, an anti venomous serum undoubtedly affords the most useful means of combating the effects of snake bite.
An anti-venomous serum can be prepared from horses, which are first inoculated with small doses of cobra venom mixed with 1 per cent hypochlorite of lime, and later with increasing doses of fully active venom. Such a serum protects animals only against the neurotoxin which is the principal active con stituent of such a venom as that of a cobra. and it cannot be expected to prevent the local effects of the hmmorrhagin which is the pre dominant constituent of most viperine venoms.
A special anti-hwmorrhagic serum can be obtained by the hyper-immunization of horses with viperine venom, however, and it is possible to obtain a polyvalent serum meeting both cases. Such serum is very often not available, however, and in many instances its cost will prevent its extensive use for the treatment of animals other than dogs.
(2) Besides a specific serum which is able to exert its influence on venom which has been absorbed, there are certain chemical substances which are able to destroy venom by direct contact, and which may therefore prove of great value if used within a short time of the infliction of the bite and if introduced sufficiently deeply to come into direct contact with the greater part of the injected venom.
Of these substances potassium permanganate and calcium hypochlorite are perhaps the most efficacious.
The best routine procedure in ordinary cases of snake-bite is as follows: (a) As soon as possible, in cases where the situation of the bite renders this practicable, a tight ligature should be applied above the bitten part, and this ligature should be kept tight for half an hour.
(b) Two or more incisions, at least 1 centi metre in depth, should be made through or over the fang punctures, and the part should be compressed to encourage the expulsion of venom from the wound.
(c) Crystals of potassium permanganate should then be rubbed well into the incisions and fang punctures, or the wound may be freely washed with a freshly prepared 2 per cent solution of calcium hypochlorite, and a few c.c. of this solution may very well be injected into and around the wound with the aid of a hypodermic syringe. The wound may finally be covered with a compress saturated with solution of potassium permanganate or calcium hypochlorite.
(d) If available, a dose of serum should then be inoculated; in most cases it is sufficient to inject the serum subcutaneously into a part well provided with loose areolar tissue, but if symptoms of intoxication are already appearing, the inoculation should be intravenous.
It is well to keep the patient warm with rugs, etc., and such stimulants as hot coffee are generally recommended for human patients. Alcohol is not advised when the serum treat ment is used, although in other cases it may be beneficial.
A number of agents which were formerly advised, such as ammonia and strychnine, are not now recommended.
In those cases in which venom is projected into the eyes (as sometimes occurs with Sepedon hcemachates, the South African" Ringhals, " and possibly also with Naia flava, the Cape Cobra) it is sufficient to treat the resulting acute conjunctivitis with mild eollyria, such as a solution of boracic acid, and to protect the eyes from light.
Literature. There are a number of records of cases of snake-bite in animals scattered throughout the literature, but for full infor mation with respect to the effects of snake-bite and the actions of venoms the standard work of Calmette should be consulted (Les Venins; also English translation by Austen).
Records of a number of experimental cases in domestic animals (bitten by South African snakes) are given by the author in the Second Report of the Director of Veterinary Research, Union of South Africa, 1912. W. H. A.
The present article on Veterinary Toxicology does not aim at being in any sense comprehen sive. All points of a more strictly chemical character are omitted, and only bare reference can be made to the large majority of rarer cases of poisoning amongst animals. Fuller details can be sought in such books as Finlay Dun, Veterinary Medicines; Winslow, Veterin ary Materia Medica; and Lander, Veterinary Toxicology.
Definition of a Poison.It is difficult to find an entirely satisfactory definition of a poison, which, however, in the stricter sense, may be defined as a substance of relatively simple chemical constitution, able to produce in com paratively small doses deleterious or fatal effects. In sub-lethal quantities one expects specific action on the organism affecting some one or more particular groups of cells, so that many poisons in smaller doses act as therapeutic agents, e.g. many metal salts and alkaloids.
A poison differs from a bacterial toxine in that it does not give rise to the formation of an anti-body in the blood serum, such anti-bodies being capable of conferring protection against poisoning in a fresh subject. But the phyto toxines, such as ricine, crotine, and abrine, and the zoo-toxines, such as snake-venom, do give rise on sub-lethal injection to anti-bodies, and thus bridge the gap between the relatively simple chemical poison and the complex bac terial toxine. In this connection it is interest ing to observe that in distinction to the toxine and bacterial poisons the ordinary poisons do not directly cause rise of temperature.
In a strict sense no agent should be considered a poison unless its action in medicinal doses is marked by specific therapeutic effects. It is desirable to eliminate damage caused by injudicious feeding or by malnutrition from the category of poisoning. Professer Cushny puts it in this way:" Some bodies may be remedies, foods, or poisons according to the quantity ingested and the mode of application." Although an ordinary poison never produces an anti-body, one must remember that con tinued dosage may bring about tolerance. This has been observed amongst animals in the arsenical treatment of piroplasmosis, and is further well illustrated by the tolerance acquired by the human subject towards alcohol, tobacco, and morphine.
Absorption, Distribution, Accumulation, and Elimination.The absorption of a poison depends on the physical nature of the poison and on the channel of absorption. As regards the former con dition, the gaseous state represents the most easily absorbable form when the gas enters the lungs. The vapours of prussic acid, carbon monoxide (coal gas), chlorine, and volatile anaesthetics act, as is well known, very rapidly on inhalation. On the other hand, a solid, insoluble in water, acid, or alkali, is in general not poisonous, even although soluble compounds containing the same active ingredient may be so. Thus, whereas the soluble salts of barium are exceed ingly dangerous, the insoluble barium sulphate is harmless when taken through the mouth, and among the compounds of lead the effects of the sparingly soluble lead sulphate are much slower than those of the more easily soluble white lead, or the soluble sugar of lead. Coarsely powdered vitreous arsenic may be given in large quantities to dogs without bad effects; the more finely powdered white arsenic is, the more readily is it absorbed, and the maximum effect is noted in the exhibition of white arsenic in alkaline or dilute acid solution. It is clear in all cases that the absorption of a poison takes place by osmosis of a solution of it into the body fluids. Certain very complex bodies such as the toxins are either incapable of undergoing osmotic diffusion or do so with extreme slowness. For this reason snake-venom is stated to be un absorbed, and therefore to produce no injury on introduction into the intact alimentary canal, whilst ricine of castor seeds is diffusible to a limited extent. The effects of such bodies are therefore incomparably greater when intro duced into the system by injection. The vegetable alkaloid curarine, amongst simpler soluble poisons, is to be noted as not very easily absorbed, whilst certain metal radicles, such as magnesium; iron, and bismuth, are not per meable through the living cell when in solution, or at any rate only to an extremely small extent.
In practice the accidental poisoning of animals by gases is exceedingly rare; in the vast majority of cases we have to reckon with absorption in solution through the alimentary tract, and more rarely with absorption through a wound which approximates to the conditions proper to administration by injection.
As regards distribution, it may be taken as established that, apart from corrosives, which produce gross lesions by destroying the living cell, a poison only acts after entrance into the general circulation. In such cases as those of prussic acid and arsenic, for which we have very delicate tests, the distribution in the organs, blood, brain, and muscle may be followed by actual analysis. In so far as chemical methods of detection are lacking in delicacy, a specific physiological effect such as that of a mydriatic alkaloid is often a better test than a chemical reaction. The liver arrests most metals, phosphorus, and many alkaloids on their arrival in the portal system at that organ after absorption, but some substances, such as the salts of sodium and potassium, alcohol, and digitalis, are not so arrested, and obviously the degree to which a poison is held up depends upon the quantity administered. The liver is thus the principal seat of storage of accumula tive poison, and it is from the liver in the majority of cases that elimination proceeds, partly by the blood through the kidneys, skin, and milk, but principally by the bile, from which a portion may be reabsorbed and carried back to the liver (Claude Bernard). It is clear that the rate of elimination varies, being most rapid with volatile gaseous poisons and slowest with heavy metals.
Variations in the Effects of Poisons.These are due to species and idiosyncrasy. The relatively immense dilution in the digestive apparatus of a ruminant, affording greater opportunity for elimination, accounts for the relatively larger pro rata dose required to produce ill effects in the ox, sheep, and goat compared with the horse or a carnivore, but the ox is more sensitive to mercury and lead than the horse. The relative degree of develop ment of the nervous system is important, particularly as regards the effects of alkaloids. Thus 2 grains of morphine is used as an ana?sthetic for a large dog, which withstands doses very much higher in proportion than those which are injurious to man. This alkaloid, acting as a hypnotic on man and the dog, is an excitant and convulsive on the cat, goat, pig, ox, and horse. Birds withstand large doses of strychnine, and the rabbit is said to be insensitive to atropine. Idiosyncrasy is illus trated in the fact that an ordinary medicinal dose of strychnine is sometimes dangerous to the dog, but in so far as in poisoning a large overdose is usually to be reckoned with, variation due to idiosyncrasy is not so import ant to toxicology as to therapeutics.
Classiffeation.Broadly and for practical purposes we classify poisons into corrosive, irritant, and non-irritant nervous poisons.
Corrosives are represented by the strong mineral acids and alkalis, phenols, and very concentrated solutions of many salts. They owe their action to their concentration, so that a poison acting as a corrosive in a concentrated form may have quite a different action when dilute. The effect of a corrosive is marked by actual destruction, by the abstraction of water, by decomposition, and by the solution of fats and proteins in the living cell.
Irritants so modify the cell as to disturb its normal course of metabolism, ultimately causing inflammation. The irritant effect is not limited to special cells of the organism, but is general, and poisons having a wide range of activity are the protoplasmic poisons, such as mercuric chloride, phenol, and prussic acid. The salts of the heavy metals are typical irritants, but nervous effects are often added to irritant effects, leading to the designation of narcoto irritant applied in practice to so many vegetable poisons. Also with the metals the local irritant effects must be distinguished from the general effects produced after absorption.
Non-irritant Nervous Poisons may be dis tinguished according to the centre affected. Local effects are not significant and symptoms only set in after absorption.
A fairly complete survey of poisons, arranged according to their physiological effects, is that of Rabuteau: Hmatic, acting on blood corpuscles: cyanides, phosphorus, arsenic, alcohol, carbon monoxide, sulphuretted hydrogen.
Hmatic, acting on plasma: silver.
Neurotic, paralyso-motor: curarine, aconitine, conine, cicutoxin.
Neurotic, spinal: strychnine, cantharidin. Neurotic, cerebro-spinal: chloroform, ether, morphine.
Muscular: solanaee, digitalis, veratrine.
Types of Poisoning.The three main types of poisoning, acute, sub-acute, and chronic, depend on the dose.
Acute poisoning follows a large dose and manifests intense symptoms, rapid denouement and termination. Irritants cause burning sensa tions, nausea, vomiting when possible, abdomi nal pain, diarrhoea, vertigo, collapse; with nerve poisons, unrest, excitement, delirium, tremors, convulsions, difficulty in breathing, cyanosis, paralysis, and coma.
Sub-acute poisoning, arising from smaller doses, leads to the same train of symptoms less rapidly developed, milder, and more protracted.
Chronic poisoning, consequent on the cumula tive effect of repeated small doses, is not common among animals.
Diagnosis. Sudden illness or death, especially following a meal, dipping, change of situation, or change of diet, is commonly held to indicate poisoning, but obviously this does not consti tute full evidence, which is only to be based on the symptoms, history, post-mortem, chemical analysis, and if possible discovery of the con crete source.
Whilst it is impossible, with very rare excep tions, to give general symptoms whereby a case of poisoning may be recognized, the following remarks may be useful.
(a) Alimentary symptoms comprise: saliva tion, foaming, colic, retching, vomiting, purga tion (which may be bloody), bloody extravasa tion of the mouth, tongue, jaws, and fauces.
(b) Circulatory symptoms comprise: acceler ated or retarded, throbbing, or feeble heart beat; hard, imperceptible, or weak, irregular pulse; cold or hot dry skin; sweating.
(c) Respiratory symptoms comprise: ac celerated or retarded, intermittent breathing, with groaning, rattling, or gasping.
(d) Motor symptoms comprise: trembling, quivering, cramp, stiffness or twisting of the neck, locking of jaws, epileptiform or convulsive seizures, paralysis of the hind or all the limbs, loss of feeling or great irritability of the skin.
(e) Cerebral symptoms comprise: fear, shrink ing on disturbance, frenzy and delirium, or de jection, hanging of the head, drowsiness, loss of sensibility, and coma.
(f) Other symptoms are contraction or dilatation of the pupil, a fixed anxious look, staring coat, suspension of lactation, repression or incontinence of urine, which may contain blood, albumin, bile, or excreted substances, such as phenol derivatives in carbolic acid poisoning. The mucous membrane of the mouth may show characteristic staining or erosion, and the breath may contain recognizable traces of volatile substances, such as prussic acid.
Treatment.Although it is rarely possible to diagnose the actual poison at work, the general symptoms as detailed above will afford a guide to the class of poison and suggest certain general remedial measures and precautions.
(1) If poisoning is suspected, where possible change the situation of the animals and the food, especially if the latter be new. Offer only food and water of proved purity. Make an immediate search for suspicious articles, remem bering that as these are easily accessible to the animals they should be looked for first in accessible and exposed places. A great deal of time is often lost in a minute and recondite search for a source of poison which lies quite close at hand, e.g. a water-cart containing weed killer. It is useful also to make a search for dangerous or suspicious plants, garden cuttings, and the like. In any case keep the patients quiet and unworried.
(2) Remove any irritant from the skin; if acid, by warm soap or soda solution; if alkali, by vinegar. Clear the stomach where possible, and, unless contra-indicated, by emetic, such as salt, mustard, and water, zinc sulphate, ipeca cuanha, or apomorphine hypodermically. Dilute the poison by fluids.
(3) Neutralise the effects. Against irritants and corrosives use demulcents. Relieve ab dominal pain by means of opium, morphine, or chloral. Stimulants are indicated against narcotics, alcohol, brandy or whisky, ether hypodermically, strong coffee or tea, inhalations of ammonia. When there is an inclination to drowsiness or coma keep moving, give douches of cold water, apply liniment of ammonia and turpentine in oil to horses and cattle.
Sedatives are indicated against convulsions.
(4) Promote excretion by means of oily purgatives, bearing in mind, however, that oils are contra-indicated in phosphorus poisoning.
Examination.The appearances should be carefully noted, although unfortun ately they are rarely characteristic; the most common observation being that of more or less acute gastro-enteritis. In general, pure alkaloids and other vegetable poisons do not produce irritation, but most mineral poisons and plants do so. A search of the alimentary contents will sometimes reveal the cause. Prussic and car bolic acids, chloroform, alcohol, essential oils, and phosphorus betray their presence by their odours. Fragments of poisonous plants, lead splashes, pieces of paint, and the husks of certain seeds, such as castor, may often be found. It is wise in all events to keep specimens, particularly of vomit or ingesta, for further examination.
Common Causes of Poisoning.The causes of poisoning amongst animals are very different from those obtaining in the human subject, which generally arise from malice or suicide. For example, poisoning by growing plants is common amongst cattle and horses, but is only found in man in the cases of lunatics and children. Malicious poisoning usually only applies to small animals, dogs, cats, foxes, and poultry, and in that case, in by far the larger number of instances the agent is strychnine given in the form of vermin-killer; less fre quently phosphorus vermin pastes and arsenic. The ox is the commonest victim of accidental poisoning, possibly on account of its less dis criminate feeding habits as compared with the horse and sheep. Lead preparations, probably on account of their sweet taste, are very often taken by the larger animals, and weed-killer and dip are also very common causes of trouble.
The continual empirical administration of con dition powders and the like by cattlemen, horse-keepers, and others, is a practice which cannot be too strongly deprecated. In spite of popular opinion to the contrary, these things do more harm than good. It is the greatest possible mistake to hope to make good on a deficient food by means of medicine.
One of the most remarkable features relating to the poisoning of animals consists in the marked difference noticed in ordinary as against experimental feeding. Whereas animals moving together and feeding together in the ordinary way will partake freely, and indeed seem to eat against one another, thus consuming large doses of poison, the present writer has never succeeded in inducing any isolated experimental animal voluntarily to eat a poisonous dose of any poison. Rather than do so the animal will starve, although it will eat a small dose once. These remarks apply especially to cattle, sheep, pigs, and chickens. It is easier to get a dog to bolt a piece of poisoned meat.
On the whole it is safe to say that the greater number of cases of accidental poisoning of animals are the result of ignorance or gross carelessness, or both, which lead people to leave lying about in exposed situations, dip, weed killer, paint, disinfectants, and the like.
In the following sections allusion will only be made to the commoner cases of poisoning, and these may be conveniently subdivided into mineral, organic, and plant. In addition to those for which such detail is given, reference will be made for the sake of completeness to cases of the rarer kind, where poisoning has been proved, or alleged to have occurred.
Mineral Poisons Lead. Origin. White lead is the commonest and most dangerous cause of lead poisoning. Besides being used as a paint, it is also used in the manufacture of oil-cloth and linoleum. The pigment red lead is also dangerous. Lead sulphate is less dangerous than white lead, but is less frequently used as a paint. The lead paint trade is an exceedingly dangerous one, and white lead substitutes free from lead are coming more into use. Lead splashes, for example, from bullets, have been often fully proved to be dangerous, but the writer has never heard of an authenticated case of poison ing through a solution of lead in soft water. Lead-smelting works emit lead fumes, probably chiefly consisting of particles of lead sulphate in such a minute state of subdivision that it is exceedingly difficult to deprive the fumes of them, and they almost partake of the properties of a gas, being carried to a great distance by air currents (see page 535).
The approximate minimum toxic doses of lead acetate are: ox, 720 grains; horse, 7500 grains; sheep, 450 grains.
Symptoms. Gastro-enteritis, colic, convul sions, coma, and death are the general effects of the acute poisoning of cattle by lead. Intense abdominal pain, grinding of teeth, nasal dis charges, salivation, pallor of mucous mem branes, constipation with passage of hard black dung, foetid breath, ropy urine, blindness, and muscular tremors, are signs. The tempera ture is nearly normal, or depressed, and the extremities cold. The nervous symptoms, marked by delirium, in which the animal rushes about blindly, often damaging itself against obstacles, often lead to a diagnosis of vegetable poisoning. The blue line on the gums, which is a marked sign of chronic lead poisoning among lead workers, is probably due to the inhalation of lead dust and is rarely or never seen in animals.
The onset of symptoms is often slow. This is well illustrated in a case signalized by Henry Taylor (Record, 1915, p. 97), in which a sow, having eaten about two pounds of white lead paint, after suffering gastric derangements looked like recovery after fifteen days, but on the sixteenth the symptoms of violent madness and blindness declared themselves, and the termination was rapidly fatal. This observa tion points to slow elimination and also indicates that some time may elapse before the lead reaches the nervous centres involved.
Slow lead poisoning such as ensues on the ingestion of bullet splashes may be protracted over such a long period as fifty weeks, and is marked by tucking up of the abdomen, staring eyes, dull look, staggering, groaning, cessation of lactation, constipation alternating with diarrhcea, gradual wasting and prostration. Fragments of metallic lead greatly corroded by the digestive juices have been found lodged in the alimentary tract in such cases. The post mortem appearances are not characteristic. Inflammation of the fourth stomach and intestines is sometimes, but not invariably, found. With the easily soluble lead preparations death is rapid and there is no inflammation, which, however, may be noticed after the ingestion of solid preparations.
Treatment should take the form of the removal of the cause by emetics, the pump, or saline purges. Dilute sulphuric acid or sul phates, such as Epsom or Glauber's salt, are stated to be useful by converting the lead into the form of the sparingly soluble sulphate, whilst potassium iodide is claimed to facilitate elimination.
Arsenic. Origin. Arsenic is very widely different in nature, especially as a constituent of many ores, e.g. of tin, lead, and zinc. As a result of this, the waters and herbage of many mining districts contain arsenic, and the principal commercial source of white arsenic is the flue-dust of the smelting furnaces. White arsenic is sparingly soluble, and the danger depends essentially on the state of subdivision. Thus it has been recorded that whereas 270 grains of white arsenic failed to kill a dog, as also did 15 grains a day over four months, , of a grain of the soluble potassium arsenite killed when given by the mouth. The soluble preparations of arsenic, which are very commonly encountered in agricultural practice, are the alkali arsenites used as weed-killers and wheat dressings, and when coloured, e.g. by red oxide of iron, as sheep dips. Other dips, as well as alkali arsenite, sometimes contain thio arsenite, arsenious sulphide, soap, sulphur, and sometimes iron sulphate. The strength of soluble arsenic in a dip prepared for use lies between 0.25 and 0.5 per cent.
Sir Arnold Theiler (Agricultural Journal of the Union of South Africa, 1912, p. 321) has published the results of numerous and valuable tests to ascertain the safe doses of arsenical sulphur clip and bluestone (copper sulphate) for sheep, these being common and easily procurable remedies for intestinal parasites. Theiler concludes that 15 grains of dip is a safe dose, as also is a mixture of 15 grains of dip and 15 grains of bluestone, but a mixture of 15 grains of dip and 15 grains of bluestone to which 15 grains each of common salt and sulphur was added killed sixteen out of eighty eight animals. The dangerous doses of pow dered arsenious oxide by the mouth, as indicated above, are very variable, but Kaufmann gives the following approximations: horse, 150 to 700 grains; ox, 225 to 700 grains; sheep, 75 grains; pig, 7.5 to 15 grains; dog, 1.5 to 3 grains; fowl, 1.5 to 1.65 grains; man, 1.5 grains.
Symptoms. The soluble arsenic compounds act rapidly, producing local irritant and remote nervous effects. In acute poisoning of the herbivorge one notes salivation, thirst, loss of appetite, vomition when possible, loss of appetite, violent colic, foetid diarrhoea of somewhat alliaceous odour, sometimes bloody, exhaustion, collapse, and death. One also notes paralysis of the hind extremities, coldness of the ears and horns, a subnormal temperature, trembling, stupor, and convulsions. The course of poisoning is sometimes so rapid that the animal is scarcely noticed to be ill.
A dose of 3 to 10 grains to a dog produces nausea, vomiting, moaning, hard and rapid pulse, painful evacuations, and death in con vulsions in from six to thirty hours. When arsenic is absorbed through the skin a scalded appearance and sloughing in patches, especially round the eyes, over the scrotum of the bull, or udder and vulva of the cow, are observed. Chronic or slow poisoning of animals is rare. It is characterised by diminution of sensibility, difficulty of movement, and eventually entire abolition of the motor and nutritive functions. Indigestion, thirst, great wasting, and chronic disease of the joints have- been observed amongst animals living near smelting works.
Intense rose-red gastro-intestinal inflamma tion with ecchymoses and extravasations are notable post-mortem signs of acute arsenical poisoning. There have been cases in which inflammation was not a prominent feature, but they should be viewed as exceptional. Fatty degeneration of the liver, kidneys, heart, and nervous centres is only to be expected in protracted cases. The preservation of organs heavily charged with arsenic is a notable feature.
Treatment is by emetics and purgatives, with milk, white of egg, and lime-water as demulcents.
Specific antidotes are calcined magnesia and precipitated iron oxide. In an emergency precipitate tincture of iron perchloride with soda carbonate, filter through a handkerchief, and give ad lib. in warm water. Morphia against pain, and strychnine and ether against prostration, both hypodermically, are recom mended.
Antimony. Origin. The preparations of antimony are somewhat rarely used in modern practice. Tartar emetic is the only common soluble preparation. The black sulphide, to the extent of about 18 per cent, along with nitre, sulphur, and spice, is encountered in condition powders. A strong solution of the chloride constitutes butter of antimony, used as a caustic.
The general effects of antimony recall those of arsenic, but are much less powerful. Vomition is caused by the local irritant effect, and with large doses there is also violent purging, weak ness, collapse, and death. Like arsenic, anti mony causes fatty degeneration of the liver and is therefore given to geese for the preparation of foie gras. Recently (1918) antimony has been observed in poultry foods, having probably been added with a view to improving condition and making good the poor quality of the food.
Some doubt has been expressed as to whether it is possible to kill a ruminant with antimony, but a healthy horse has been killed with 10 ounces of tartar emetic. In spite of conflicting opinions, the dangerous and often fatal effect of condition powders on horses must be taken as fully established.
Common Salt.The question of poisoning by common salt is complicated by its confusion with brine poisoning, which is probably due to bacterial toxin action. This opinion finds support from the circumstance that the toxicity of herring brine decreases on keeping while the concentration of salt increases. It is impossible to state the dose for the pig, which has been quoted at from 4 to 8 ounces, but the writer has given six consecutive 3-ounce doses without abnormal results. Cattle have been stated to have been killed by 4-pound doses. In cattle, pigs, and fowls, salt poisoning leads to loss of appetite, excessive thirst, and frothing at the mouth. Vertigo, convulsive movements, dilatation of the pupils, blindness, and convulsions occur with the pig, similar nervous symptoms being observed in fowls. The temperature in all cases is normal or slightly depressed.
The best treatment of salt poisoning is abun dant water. An experimental fowl ate during the course of a few hours a full poisonous dose of salt without ill effects, because it partook freely of abundant water, which was simultane ously offered.
Nitre.The nitrates of sodium and potassium are more dangerous than common salt, a pound being poisonous to the ox, and 1 ounce to the lamb. Nitrates cause gastro-intestinal irritation, trembling, convulsions, dilatation of the pupil, and paralysis of the voluntary movements.
Sulphur.Horses have been known to have been killed by 8 to 14 ounces each of sulphur. In the horse it causes dulness, pain, and diarrhcea, the faeces smell of sulphuretted hydrogen and are fluid, black, or grey.
In the dog violent colic, diarrhcea, and vomition, at first bloody and eventually of pure blood, with an almost imperceptible pulse and coma, were followed after twenty-four hours by recovery. Apart from intense gastro-enteritis, a smell of sulphuretted hydrogen and the possible detection of particles of sulphur are post-mortem signs.
In treatment, castor-oil, eggs and milk, sub nitrate of bismuth, chlorodyne, and whisky have been found useful.
Phosphorus.Ordinary or live phosphorus compounded with a suitable grease, as a rat powder, is the only phosphorus preparation likely to cause damage to animals, and then most usually with the dog, cat, and fowl.
The dangerous dose depends largely on the state of subdivision, 0.7 to F5 grains being given as the poisonous dose for the dog. Phos phorus is absorbed as such into the blood-stream and is given out in the exhaled breath, which therefore smells of phosphorus and glows in the dark.
Phosphorus acts as a local irritant, but as it is slowly absorbed the onset of symptoms is often delayed. Uneasiness, nausea, vomiting, and eructation ensue, with fever, thirst, and abdominal pain. In the second phase jaundice, nervous effects, delirium, convulsions, and coma precede death. The jaundice is attributed to the enlargement of the liver cells preventing the flow of bile in the ducts. Birds display great stupor or remain huddled up, beak open and comb blanched, thirst, diarrhoea, convul sions, and coma preceding death.
The prognosis of phosphorus poisoning is unfavourable.
Treatment. The stomach should be emptied, if necessary by the tube. Copper sulphate is used both as an emetic and antidote. Old (oxidized) French turpentine is a well-known antidote of doubtful value. Avoid the use of oils which promote absorption.
Other Metals.Some of the salts of mercury, copper, zinc, silver, barium, and chromium may give rise to poisoning. This applies to such preparations as are soluble; thus calomel and barium sulphate are harmless, unless the former is given in very large doses. Again the oxide, carbonate, and weak acid salts of zinc are apparently innocuous, the sulphate of zinc being an emetic, and the chloride a caustic irritant.
Soluble barium salts, e.g. the chloride, which is used as. a purgative, produced poisoning re sembling that of lead.
Poisoning by mercury is rare, although corrosive sublimate (the soluble bichloride) is a powerful protoplasmic poison. Mercury pre parations are very rarely exposed in access ible situations, which no doubt accounts for the rarity of cases. The writer, however, once encountered a case in which the deposition of finely divided metal on herbage, as the result of an explosion in a fulminate factory, led after several months to deaths of cattle.
The soluble salts of copper, of which the sulphate, or bluestone, is a good example, are dangerous. For instance, Theiler states that 45 grains upwards causes the death of sheep from acute gastro-enteritis. The green pigment, Scheele's green or copper arsenite, is naturally very dangerous. It is not often used as a paint, except for outside work, but recent cases of damage by it have been observed.
In general it may be said that poisoning by any of the above agents pursues the course common to that noticed with the other irritant heavy metals.
Acids and Alkalis.Brief mention will suffice of such other inorganic agents as strong mineral acids and caustic alkalis. Cases of damage by them are rare in practice, although the extension of chemical manufacturing activities in recent years leads to considerable production of contaminated effluents. Such effluents are very dilute, and calculated to produce chronic digestive trouble rather than to display the drastic corrosive effects of the strong agents. Removal of the cause is the only satisfactory counter-measure. Alkali is obviously antagon ized by weak acid (vinegar), and acid by weak alkali.
Poisoning of animals by gases, such as coal gas, is rare, although poisoning by ammonia fumes has been recorded, and an extremely interesting case of the emission of fumes of hydrochloric acid from a volcanic fissure in the Kelong valley, Africa, has been described by Stordy (Journ. Comp. Path., 1908, p. 75).
Organic Poisons Under the heading Organic Poisons one includes the isolated alkaloids or extracts of medicinal plants and such artificial or natural organic products as prussic acid, carbolic acid, and the like.
Hydrocyanic Acid; Prussic Acid Hydrocyanic or prussic acid is one of the most powerful known poisons. It is fairly commonly encountered either from natural or artificial sources, and cyanides find extensive application in pharmacy, the electro - plating and photographic arts, and on the large scale in cyanide gold extraction.
Cyanides are produced on the manufacturing scale in the course of the deprivation of coal gas of its cyanogen compounds, and are also manufactured by other processes.
In nature hydrocyanic acid results from the fermentation by enzymes of certain glucosides, notably amygdalin of the bitter almond, the peach kernel, and other seeds; linamarin (or phaseolunatin) of the common flax, and Phaseolus lunatus, the Java, Rangoon bean, or Haricot de Lime, species of Vetch, and certain of the Gramineas, e.g. the millet or sorghum, and maize. The various species of Prunus also give rise to hydrocyanic acid, and the South African Dichapetalum cymosum, gift - blaar or poison leaf, is very dangerous, 1 ounces sometimes and 2 ounces always being stated to prove fatal to sheep.
The quantity of glucoside contained in the wild varieties of Phaseolus or Java bean, which vary in colour from pale reddish brown to purple, amounts to rather more than 0.1 per cent. It is noteworthy that under cultiva tion the percentage of cyanogenetic glucosidc dwindles, the white haricot or butter bean being harmless. From the practical standpoint only the dark - coloured or purple beans need be regarded with suspicion. Linseed cake rarely yields more than 0.025 per cent of hydrocyanic acid, although as high a percentage as 0.055 has been noted; it is therefore only exception ally that danger is to be apprehended from this source, as is fully borne out by practical experi ence in numerous feeding tests. In connection with cyanides it is well worth while pointing out that many of the numerous derivatives, in particular red and yellow prussiates, sulpho cyanides, and mustard oils or organic sulpho cyanides, are either comparatively harmless, or dangerous through other causes. Indeed sulpho - cyanides are constituents of human saliva though not found in that of the ox. The mustard oils are dangerous by reason of their powerful irritant effects, and do not typify cyanide poisoning. It is a great mistake often committed in medico-legal practice to class everything in which cyanide occurs as part of the name as a deadly poison. As regards toxic doses, Kaufmann gives 6 grains in the form of 2 per cent solution for the horse, and 0.6 grain for the dog.
Potassium cyanide is less toxic; thus for the dog Kaufmann gives 4.5 grains, which is equiva lent to reckoned as pure acid. A heifer examined by the writer withstood potassium cyanide equivalent to grains pure acid, but was killed by cyanide equivalent to 30 grains taken by the mouth. Calculating on 20 grains as the minimum toxic dose for cattle, it is reckoned that two pounds of the most dangerous Java beans would be necessary to cause death, while at least eleven pounds of linseed cake would have to be used. In conse quence of the rapid elimination of hydrocyanic acid, even such an unusually large feed of linseed cake would probably fail of its effect.
Symptoms. Very large doses are rapidly fatal owing to arrest of the heart and diastole. Toxic doses, after a brief, powerfully stimulant effect, lead to depression, paralysis, and diminu tion of blood tension.
In cases of poisoning by cyanide-producing plants, the train of symptoms is almost always complicated by irritant effects due to other constituents, e.g. an essential oil in the cherry laurel. Animals poisoned by hydrocyanic acid or Java beans do not show inflammation. There is congestion of the central nervous system and the lungs; fluid, black and oily blood; the cavities of the heart contain bubbles of gas, and all parts of the corpse have a faint smell of bitter almond. As we are in possession of delicate methods in this case, it is possible to test chemically and demonstrate the presence of prussic acid even in the brain substance after minimum doses.
Treatment. The treatment of prussic acid poisoning is exceedingly difficult. Removal of the cause by emetics or pump, and measures against prostration should be adopted. The following have been recommended: atropine; sulphide and thiosulphate of soda in the hope of producing the comparatively harmless sulpho cyanides; ammonia; chlorine; anaesthesia under ether. The best-known antidote is freshly pre cipitated ferrous hydrate made from iron sulphate and liquor potassm. It is given in the hope of converting the cyanide into the harmless ferro cyanide, but there is rarely time to apply the antidote in any case.
Carbolic and Tar Acids.The pure carbolic acid is rarely used outside of the laboratory and pharmacy, and therefore is not often responsible for poisoning. The cresols (homo logues of carbolic acid) form about 3 per cent of the heavy, or creosote, oil of tar. The so called tar acids are blackish liquids running up to 25 per cent of cresols, and moreover the pure cresols are manufactured on the large scale technically.
Coal tar dips, and such disinfectants as creolin and lysol, are all of them essentially concentrated homogeneous solutions of tar acids more or less pure, with resin soaps in dips and soft soaps for higher grade preparations. They form emulsions with water.
Oil bf tar, mixed with vaseline or mineral lubricating oil, to which finely divided mercury is sometimes also added, is a common mange dressing for horses. Tar acid products may also be encountered in effluent waters from gasworks, tar distilleries, and coke oven plants. The tar acids are somewhat dangerous, the Depart mental Committee on tar dips having found that a per cent tar acid dip caused grave symptoms, a 0.75 per cent tar acid dip being safe.
Symptoms. A diluted carbolic acid after absorption exercises marked effects on the central nervous system, illustrated by weakness, stupor, and tetanic convulsions similar to those produced by strychnine, choreic movements, followed by paralysis of the locomotor system, and death.
The concentrated acid is a violent corrosive. Hobday carefully investigated the use of creolin, chinosol, and izal. With delicate breeds of dogs and cats he advises that the total application of creolin should not exceed 10 to 15 minims. In poisoning he observed subnormal tempera ture, paralysis of hind legs, followed by complete paralysis, prostration, and chronic spasms well marked in limbs, jaws, and eyelids. Death from collapse follows coma.
Dollar on the whole agrees with Hobday. He found that a cat of seven pounds weight, three years old, after rubbing with 5 drachms of Jeyes' in 5 per cent solution, was poisoned and died within fourteen hours. He argues, however, that this preparation is no worse than any other lotion or efficacious agent.
Treatment. In. treatment sodium sulphate is given in the hope of promoting the formation of sulpho-carbolates, which are easily eliminated. An emetic of zinc sulphate is recommended for small animals, followed by egg albumen in milk and a mixture of chlorodyne and lime water. With large animals strong purgatives and whisky have proved successful when the purge acted. Oil of turpentine has been usefully employed.
Strychnine. Origin. This alkaloid occurs, together with brucine and igasurine, as the active principle of the seeds of varieties of strychnos, particularly strychnos nux vomica of East Indian habit. The powdered seed con stitutes 11111E vomica powder. The amount of strychnine varies from to 2 per cent. Brucine is present in larger proportions, has the same general actions, but is less powerful.
Strychnine is a very common constituent of vermin powders, in which it is mixed with starch or flour, and blue or soot. The existence of these preparations renders strychnine an accessible poison, and makes it responsible for a large proportion of cases of poisoning among dogs, cats, and foxes. It is also used to protect stacks from vermin, and as a grain dressing. In this latter respect advantage is taken of the fact that birds are relatively immune, and that whereas sparrows may be destroyed, fowls may escape.
Strychnine is very toxic, and the poisonous doses are fixed by Kaufmann as follows: horse, 3 to 4.5 grains; ox, 3 to 6 grains; pig, 0'15 to grain; dog, to grain. For the dog this is roughly between one-thirteenth and one-third of a grain. Putting the dog at the equivalent dose for man is and for the fowl 2 grains, which well shows the relative order of sensitiveness. In practice strychnine is only given to dogs in small and carefully regulated doses, one-hundredth of a grain being given with caution to toy varieties. One-thirtieth of a grain has caused strychnine spasms in a fox terrier.
Symptoms. Strychnine is a powerful stimu lant to the central motor cells, and greatly increases the reflex irritability. After paralysis of the peripheral nerve - endings by cocaine, injection of strychnine fails to produce the tetanic convulsions. Under the influence of strychnine such a gentle stimulus as a slight air current induces a normal reflex immediately followed by the characteristic general tetanic spasms, during which the back is curved, respiration is arrested, and the muscles are tense. Death results from asphyxiation, the respiration usually ceasing after two or three spasms. During the spasms the rigidity of the extended limbs is so great that a small animal may be lifted in a perfectly straight position by one extremity. Macqueen observed strychnine symptoms in the treatment of paralysis in the horse by doses increasing from 1 to 5 grains twice daily. Twitching of the superficial muscles is a preliminary warning. The horse rears, falls and makes galloping movements, so that it moves backwards on its side in a circle. Tobacco gives relief. Dogs become very uneasy, whine, are nauseated, and sometimes vomit. The general tetanic spasms occur with in creasing violence at intervals of one, two, or more minutes until death, which is rapid after the first onset of symptoms.
Post - mortem reveals the appearances of asphyxia, rigor mortis is characteristic, but its absence is not a decisively negative sign. The feet, or in birds, the claws, are generally in curved, and the muscles of the jaws are rigid.
Treatment. Unless the dose is large, and pro vided the cause is promptly recognized, treat ment is hopeful. Remove the cause, giving a tenth to half a grain according to size, of apomorphine as an emetic. Chloroform inhala tion, or morphine, is useful, but chloral, 6 to 20 grains, according to size, by the mouth, is the best physiological antidote. In giving anti dotes by the mouth there is danger, for if a spasm occurs the liquid may pass into the trachea and suffocate. Remembering that mor phine causes excitation in the lower animals, the use of chloral is greatly to be preferred.
Morphine and Opium. Origin. Morphine forms the chief constituent of the alkaloids of the Opium poppy, Papaver somniferum, native to Southern Europe and the Levant. Codeine and narceine are also hypnotics, whilst thebaine, papaverine, and narcotine are convulsants.
The lower animals, by reason of their inferior cerebral development, withstand far larger doses of morphine than man. The doses ordinarily given to dogs for anaesthetic purposes would prove fatal to a man. Four grains per pound body - weight represents a fatal dose for the dog. To kill the horse 75 to 100 grains would be needed. Sixty grains given by the mouth to a pony evoked no marked symptoms, and, after slaughter, impaction of the stomach con tents due to gastric paralysis was the only sign of action. The symptoms of nausea, indigestion, and tympany are due to the arrest of the digestive functions. The excitant effects of morphine are conspicuous in the lower animals. In the ox and home the animal moves in a circular direction, butting regularly into ob stacles, and giving the general impression of madness or marked delirium. This phase may be protracted, and is eventually followed by coma, respiratory failure, and death. The ex citant effects of morphine are enhanced in the action of the allied heroin (diacetyl morphine). In treatment remove the cause, combat ex citement by cold applications to the head and depressant effects by caffeine. The stimulation of small doses of atropine seems useful.
There is very little chance of the accidental poisoning of animals by morphine or the allied alkaloids, and the same holds for such alka loids as cocaine, eserine or physostigmine, pilocarpine, emetine, gelsemine, veratrine, cura rine, etc., particularly as none of the plants from which these alkaloids are obtained is indigenous to the temperate zones. They are a part of pharmaceutical equipment, and as such are, or should be, under control.
Poisonous Plants Anything approaching a full enumeration of the plants which are definitely known as poisonous, still more those to which suspicion of causing damage attaches, would be altogether outside the scope of an article like the present. Particularly in view of the existence of such a comprehensive work as that of Cornevin, Des planter veneneuses, which covers European and many North African species, and having regard further to the somewhat monotonous uniformity in the recorded symptoms alleged to result from the ingestion of different plants, a list in this place of the principal suspicious species and varieties is amply sufficient. On the other hand, however, there are certain genera, regarding whose toxicity long experi ence is fortified by concrete illustrations in point, and more detailed reference will there fore be confined to them, alluding in the first instance to British and North European plants.
The order Coniferm includes yew, or Taxus baccata, and varieties, which are common trees, and which, apart from containing irritant oils, contain the very toxic non-irritant alkaloid taxine. A remarkable feature of yew poisoning is its rapidity; often, whilst quietly chewing, cattle drop as if shot, and have been known to die while in the act of eating the plant. After eating yew, an animal will stop suddenly, start blowing and trembling, fall, and die quietly within five minutes, with symptoms like apo plexy. The alkaloid paralyses the alimentary system with stoppage of digestion and conse quent symptoms. Intense inflammation of the stomach is almost invariably observed, but it rarely extends to the intestines. The prognosis is very grave.
Treatment. A soda bicarbonate emulsion of one pint of linseed oil with two ounces each of chlorodyne and nitrous ether, followed by whisky and linseed oil, and later stimulants and ehlorodyne, has been successful. If the diagnosis is certain, Wallis Hoare recommends rumenotomy.
Apart from general treatment the depressant action may be combated by means of digitalis, ether, or atropine.
This order also includes the black and green Hellebores, which should not be confused with the white Hellebore, V eratrum album, belonging to the Colchicaceae.
Hellebore acts as an irritant and at the same time on the heart in a somewhat similar manner to digitalis.
Members of the genus Ranunculus, which are common weeds of cultivation, contain acrid juices whose chemical nature is not well ascer tained. All the species are to be regarded as suspicious. Ranunculus first produces gastro enteritis, colic, nausea, vomiting if possible, salivation, emission of black faeces, and some times hmaturia. There are nervous symptoms, with retardation of pulse, slow and stertorous respiration, weakness of the posterior parts, difficulty in mastication and drinking, and blindness.
Treatment. J. Gerrard successfully overcame common buttercup poisoning of the horse by nitrous ether, aromatic ammonia, extract of hyoscyamus, peppermint water, tincture of opium, and a four-drachm ball. In spite of the extreme commonness of the varieties of Ranun culus it is not freely taken by animals, except in case of scarcity or when they are confronted by the plant for the first time.
Cruciferae.The Cruciferae include mustard. White and black mustard flower each contains a glucoside giving rise on fermentation to the respective essential oils of mustard, oxybenzyl sulpho-cyanide from the white, and ally' sulpho-cyanide from the black. It has long been known that the whole seed is quite harm less, passing through the system unaltered. Whether the dangerous effects of crushed mustard seed are due to the essential oils or to some other constituent, it remains a fact well established as far back as 1861 that the presence of crushed mustard seeds in oil cakes, notably rape, makes them exceedingly danger ous. About a pound of such cake may cause fatal poisoning. J. Gerrard in 1875 gives the following picture of the poisoning of cattle: uneasiness, restlessness and intense colic, with frantic rushing about and mania, ending in exhaustion, falling, struggles, and collapse. Gerrard quotes this as a good example of an irritant poison. His narrative is almost textu ally reproduced in very recent accounts received from different sources relating to mustard cake poisoning. Even a press cake of mustard husks after milling has produced similar effects. In all such cases the rumen contents smell of oil of mustard, and complaint is sometimes made by the men engaged in handling the corpses, of the stinging effect on the thin skin of the fore arm. The frantic mania, which is characteristic of mustard poisoning, was not noticed in a case of illness among cattle eating wild mustard on pasture. The cause in the latter instance was probably different.
Legurninosm.Amongst the Leguminosae refer ence has been made, under" Hydrocyanic Acid, " to poisoning by the Java or Rangoon bean.
The yellow lupin is held responsible for sheep poisoning on the Continent, and according to the German authorities a daily ration consisting of a pound of the whole plant, three-fifths of a pound of empty pods, or half a pound of the seeds, will produce poisoning, marked by in appetence, dyspnea and fever, haematuria, cir culatory and digestive derangements, trembling spasms, and vertigo. Jaundice is characteristic.
Lathyrism.Several varieties of the genus Lathyrus, such as Dogtooth, Indian or Mutter pea, are dangerous. Their ill repute indeed goes back to the days of Hippocrates and Pliny. The cases of poisoning amongst horses appear to have been first recorded in England in 1886. The causation of lathyrism is obscure, no certain conclusions as to the active principle having yet been reached. Lathyrism is only produced when considerable portions of the pea enter into the rations over a prolonged period of time—in man about four months, in the horse fed exclusively on the pea, ten days, but when one to two quarts only are given daily, towards the eightieth day. The malady
may declare itself as long as fifty days after the cessation of the feeding.
Paralysis of the lower extremities is a con stant sign of lathyrism in man. M'Call in 1886 placed on record complete observations on the horse. An animal was feeding well but thick in its wind. After going about two hundred yards with an empty lorry it stood with the fore-legs forward, neck stretched, elbows out, and laboured breathing. It was with difficulty kept on its feet until unyoked, and each breath gave a loud sound from the larynx. There was profuse sweating, quick, irregular and intermittent pulse, increased impulse of the heart, venous pulsations, normal tempera ture, and a vibration over the region of the larynx. The symptoms disappeared after about five minutes, and the animal began to eat hay. Later accounts substantially agree. Sometimes the paroxysms prove fatal, otherwise there is a speedy temporary recovery. Change of diet, at any rate at first, does not arrest the malady.
With sheep and pigs and experimental dogs, paralysis of the hind extremities is notable.
The only effective treatment, besides removal of the cause and rest, appears to be tracheotomy.
Loco disease is common in Colorado and Montana, and as with lathyrism the etiology is obscure, but no doubt is felt that the disease is caused by leguminous plants of the Astragalus species.
In acute locoisin in sheep the animal becomes unmanageable, completely blind and dizzy, walk ing in long circles to the right, and then standing for a few moments in a stupor. The head is elevated and drawn to the right at the beginning of an attack, and these become more frequent as the malady progresses. The expression and pulse are nearly normal, and the pupil is not dilated. Trembling fits are characteristic and the animals tend to bolt in an erratic manner.
Umbelliferse.Conium maculatum, or Spotted Hemlock, is the source of the volatile alkaloid conine, and as a common weed has caused dangerous poisoning of the larger animals. The general effect of conine is that of a para lysant. In the horse the plant produces nausea, accelerated respiration and dyspnea, muscular trembling beginning in the posterior members, and paralysis. There is loss of sensibility, subnormal temperature, rapid pulse, and death by arrest of respiration. In cattle, profound stupor and arrest of digestion; sometimes constipation, but in other instances bloody evacuations.
Treatment is by evacuation of the stomach and purgation; tannic acid to remove the alkaloid; warmth and stimulants.
The same natural order includes Cicuta virosa, Cowbane or Water Hemlock, whose root is very dangerous. The active principle, cicutoxin, is a powerful narcotic. Cobbold observed a case in Brittany where eleven beasts died with violent symptoms of vertigo. Animals appear to die without a struggle.
ffnanthe crocata, or Water Dropwort, has in its root cenanthotoxin, apparently closely re sembling cicutoxin in its effects. In 1835 a gang of convicts at Woolwich suffered from poisoning from this cause. ffnanth, e appears also to possess irritant principles. Wallis Hoare observed well-marked delirium followed by rapid death in cows poisoned by roots left in a field after a flood. In the horse nervous symptoms predominate, and with the pig large doses kill with the rapidity of cyanide.
Ericacea3. This family includes the orna mental shrubs, Rhododendron, Azalea, and Calmia. Rhododendron leaves are dangerous. In cattle and sheep they produce intense pain, diarrhoea and discomfort, gritting of the teeth, salivation, and frequently vomition. There is cessation of lactation, trembling, spasms, loss of power, and death. Brisk oleaginous purgatives, followed by chlorodyne or counter-irritants to abdominal pain, followed by stimulants and tonics, prove successful in the treatment of Rhododendron poisoning.
Solanaceze. The four British genera Atropa, Hyoscyamus, Datura, and Solanum comprise some of our commonest poisonous plants. To them may be added the exotic tobacco plant, Nicotiana tabacum. These may be sub divided according to the active principles into the Atropine group—Atropa belladonna, Hyoscya mus, and Datura, which contain the mydriatic alkaloids atropine and its congeners; the Solanine group—Solanum dulcamara, or Bitter sweet, and the potato, containing the glucosidal alkaloid solanine; tobacco, containing the volatile alkaloid nicotine analogous to conine.
The most dangerous of these is Atropa bella donna, or Deadly Nightshade, which frequents waste and stony places in chalky districts. By reason of its scarcity, and further because most of the atropine is in the roots, cases of poisoning by the plant are very rare. The possibilities of poisoning by the pharmaceutical preparations atropine and extract of belladonna are naturally more restricted. Atropine inhibits secretion and leads in animals to dryness of the mouth, and causes an increase in temperature and pulse and respiration. There is dilatation of the pupil, blindness, nervousness, delirium, and muscular trembling. After the period of excitement there is fall of temperature, con vulsions, motor and sensory paralysis, feeble and slow respiration, relaxation of the sphincters, and death in convulsions. One grain of atropine sulphate subcutaneously evokes symptoms in the horse. The pig, goat, sheep, and rabbit are said to be tolerant to the root, but the alkaloid on injection causes typical symptoms. Bella donna liniment sometimes produces symptoms in the small animals either by reason of absorp tion or more usually of licking.
Hyoscyamus niger, or Black Henbane, contain ing principally the alkaloids hyoscyamine and hyoscine, acts as more powerfully depressant than Atropa. In the very rare cases of poisoning by it, in contradistinction to poisoning by atropine, profuse salivation has been observed.
Datura stramonium, or Thorn-apple, is rather rare in England, but is a common weed in the United States known as Jimson weed, and also in South Africa, where it is called Stinkblaar. Poisoning by it resembles that due to atropine, which is in harmony with the fact that the active principle, formerly regarded as a single substance and called Daturine, is a mixture of the mydriatic alkaloids atropine, hyoscyamine, and hyoscine. The post-mortem appearances of poisoning by these plants are not characteristic, being those of asphyxia.
Cases of poisoning by Solanum dulcamara and the potato are probably due to the same cause. The unripe and green potato, as well as the old, rotten, or sprouting tuber is dangerous.
In poisoning by the potato, all accounts agree as regards the general narcotic effect. In general there is depression, loss of appetite, cessation of lactation, gritting of the teeth, and profound prostration with remarkable somno lence. Mydriasis is not always observed. A period of constipation is generally succeeded by diarrhcea, and, when possible, vomition. In less acute cases, to the dominant feature of prostra tion there are added intestinal irritation and rapid loss of flesh.
The post - mortem appearances are not characteristic.
In treatment strychnine subcutaneously is indicated and has proved successful. In the few recorded cases of poisoning by bittersweet, greenish diarrhcea is in addition noticed.
Cases of tobacco poisoning have been observed, and usually result from the use of tobacco juice as an external application. The main features in such cases are profuse sweating, tremors, nausea, disturbance of the respiration, and dilatation of the nostrils; later there is profound prostration and deep coma. Strychnine has been found useful in the treatment of nicotine poisoning in the dog.
Scrophularinew. The commonest poisonous member of this family is Digitalis purpurea, or Foxglove, whose leaves and seeds are the prin cipal sources of digitalis. The toxic doses of the green leaves are small. Cornevin quotes four to five ounces for the horses, six to seven for the ox, one for the sheep, and a half to three quarters for the pig. Digitalis is an irritant, but its important physiological effect is on the heart, causing increased and prolonged systole with diminished and shortened diastole. In poisoning, the heart is arrested in systole. It is a powerful diuretic, tends to be cumulative, and is contra - indicated in kidney disease. Hard breathing, erratic feeding, lassitude, an almost imperceptible pulse, contracted pupil, and excessive urination have been noticed in cattle and horses after eating hay containing dried foxglove. In horses which had eaten foxglove there was observed sleepiness, swollen eyelids, dilated pupils, normal respiration, pulse 65 to 75, and the second heart sound frequently obliterated; later the breathing became laboured, head immensely swollen, tongue greatly enlarged and protruding, pulse SO and most erratic, great restlessness. The respiration became more difficult and stertorous, tongue and buccal membranes livid, jugular, Standing out.
In a case of the poisoning of pigs by decoction of digitalis leaves the cbief feature was languor and sleepiness. The animals refused to eat or drink, attempted to vomit, and repeatedly passed small quantities of faeces. Curiously, urination was scanty and strained.
Treatment consists of the administration of tannic acid followed by an oleaginous purge and general stimulants.
Euphorbiacem. The most important danger ous plants of this family are the exotics Ricinus communis or castor, Croton tiglium or croton, and Jatropha curcas, or purging nut.
Many species of Euphorbia, e.g. Euphorbia hibernica, or Irish Spurge, which is used for poisoning fish, contain acrid juices and may be dangerous. The South African Euphorbia genistoides or Piss grass contains an acrid irritant juice. The outstanding feature of its action is severe urethritis, the attempts to urinate being frequent and painful. The animal lies down, the bladder becoming more distended, and dies in coma, or in a violent effort at relief.
Castor Poisoning. The castor - oil seed is extensively imported for the sake of the valuable oil used not only in pharmacy, but also as a. lubricant for high-speed machinery. The press cakes are unfortunately useless as food-stuffs, since they contain the exceedingly dangerous toxine, ricine. It should be noted that the ricine is contained in the body of the seed, and not in the husk. As indicated in the introduc tion to this article, this and other vegetable toxins are bodies of unknown constitution but extraordinary physiological activity, analogous to snake venoms, and they serve in a manner to bridge over the gap between the relatively simple poison and the bacterial toxine. Like the latter they are distinguished by giving rise on sublethal dosage to specific antibodies, and by being destroyed by heat, 56° C. being the minimum lethal temperature. Unfortunately, however, especially when dealing with a mass in the dry state, it is exceedingly difficult to ensure complete destruction of the ricine, even at a steam heat, although this has been success fully done on a large scale. An animal immunized to ricine is able to withstand four to eight hundred times the ordinary full toxic dose. Its serum then contains a specific antibody which is able to protect a second subject against ricine only, but not against crotine or any other toxine, and which gives a precipitin reaction with ricine extract. As is to be expected from a toxine poison, enormously greater doses are required by the mouth than on injection.
Castor seeds have produced fatalities among horses and cattle. In horses the poisoning is marked by extreme dulness, loss of appetite, coldness, abdominal pain, and constipation. Purgation has only been noticed in relatively few instances, and greatly assists recovery. With cattle, diarrhcea and bloody purgation have been held to be characteristic, but this is not in accordance with the facts. On experi mental tests we have noticed pale and foetid diarrhoea in young calves after one ounce of whole seeds, Pressed seeds up to eighteen ounces tended to make the faeces dark or hard. The ordinary small seed is less toxic than some of the larger varieties (R. sanguineus—R. Zanzibariensis) which are cultivated for orna mental purposes. Fourteen and sixteen ounces respectively of these seeds killed where eighteen ounces of the ordinary seeds had failed. Diarrhoea was not marked, nor were the evacua tions bloody; the general toxic action prepon derates over the local irritation. In croton poisoning the effects of the drastic irritant croton oil predominate.
Treatment. Morphine sulphate, or the equivalent of tincture of opium in drenches of mucilage, cornflour, or arrowroot, have been recommended successfully in treatment.
Many plants and foods have been reputed to be poisonous, amongst them cotton cake, brewer's grains, and beet pulp residues. It seems doubtful in all these cases whether there is any definite poisonous principle at work.
Undecorticated cotton cake may cause im paction.
Beet residues and beet molasses are very rich in saline constituents; in order that they may be utilized as food-stuffs it is necessary to bring the animals on to them by cautiously feeding small quantities in the first instance.
Acorn Disease. The remarkable disorder known as acorn poisoning affects cattle, but not sheep, deer, or swine. Its features were first clearly investigated by Simmonds and Brown in 1871. The symptoms are not declared until after the acorns have been digested and ex pelled. In the early stages there is constipation, succeeded by persistent diarrhcea, with frequent small dark and bloody evacuations. There is loss of appetite, suspension of rumination, wasting, colic, and excessive urination. The temperature may be subnormal. Soreness of the mouth, pallor of the membranes, and a discharge from the nose and eyes, which are sunken, are noticed. The lesions are in general those of an irritant poison. Treatment is by oleaginous purgatives and opiates.
Bracken. Bracken poisoning is another obscure malady. Storrar in 1893 drew attention to the poisoning of cattle by bracken, and was inclined to attribute it to the indigestibility and not necessarily to any specific toxic effect. The symptoms summarized in the 1909 Report of the Chief Veterinary Officer of the Board of Agriculture are: Temperature, 104° to 107° F., Joss of appetite, blood-tinged discharge from the mouth and nose, blood from the bowels, pallor of the membranes of the eye: great depression, coma; and death in from twelve to seventy-two hours after the onset of symptoms. The disease produces congestion of the stomach and intestines, and notably there are hie in the heart and body muscle and under the skin. It is suggested tentatively by the Board that the weed tormentil, Potentilla tormentilla, which occurs along with bracken in many localities, may be in part responsible.
Food may be defined to be any solid or fluid taken into the body for the purpose of growth and repair of tissues and the production of heat and energy. This definition excludes the atmo sphere. There has been some controversy as to whether the atmosphere ought not to be included as food, because undoubtedly the body receives from the atmosphere an amount of oxygen which is useful both for growth and repair and the production of heat and energy, but it is generally agreed that food only includes what passes into the gastro - intestinal tract. The health and usefulness of the lower animals are to a great extent a question of proper feeding. The prin ciples of feeding are the same with all the lower animals, although this article will specially deal with horses.
There is no doubt that considerable economy could be effected in most large stables were the principles of feeding properly understood and applied. It should first of all be grasped that the body makes the best use of food if the different food constituents are in certain pro portion to each other; that if they are not, some portion of the food is either wasted or may even produce disease. It should also be remembered that the horses or cows in the stable have no power of selection. They have to eat what is given them or go without.
The different constituents of food are familiarly known as the proximate principles, some of them complex chemical compounds but elementary so far as the building up of the body is con cerned. Every blade of grass and every seed of corn contain these proximate principles but in varying amounts, some are rich in one and poor in another, others contain them in the correct proportions. These proximate principles are first of all divided into two classes, the organic and the inorganic, the inorganic com prising the mineral salts, to which reference will be made more fully later.
The organic proximate principles are divided firstly into those containing nitrogen and those without nitrogen. Those containing nitrogen are known as proteids or albuminates or often albuminoids. Chemically they contain the elements carbon, hydrogen, oxygen, nitrogen, sulphur, and occasionally phosphorus. The chemi cal composition of a proteid is Proteids are divisible into two great groups according to their nutritive value. The more nutritious consist of albumin, glutin, casein, myosin, and legumin. The other group, less nutritious, is more concerned with the food of carnivore and consists of gelatin (from boiling bones and cartilage), chondrin, ossein, and keratin. Glue is really an impure form of gelatin got from boiling horns and hoofs.
Albumin is the essential constituent of that substance which, called by physiologists proto plasm, really is the physical basis of life.
The white of egg is almost pure albumin. Glutin is the name given to the albumin of most cereals, and can easily be demonstrated by placing some wheat flour in a muslin bag and running a stream of water through it. The milky water passing from the bag is due to the presence of starch, the sticky substance left behind in the bag is nearly pure glutin. Myosin is the name given to muscle or flesh albumin, casein to the albumin of milk. It is the curd which is formed when an acid is added to milk. Legumin is the albumin of the pea and bean tribe (Leguminos). Avenin is the albumin of oats and gliadin that of wheat. Most of these albumins are coagulable by heat. Casein is an exception.
The passage of a food proteid through the body is as follows: It is unacted upon in the mouth. In the stomach, by the action of the gastric juice containing pepsin and hydrochloric acid, it is converted into what is known as peptone, which is a soluble form of proteid, and passes from the stomach into the bowels, whence it is absorbed by the lacteals and passes into the blood. Such of the proteids that are not digested by the gastric juice are further sub jected to the digestive action of pancreatic secretion containing a ferment" trypsin, " and by intestinal secretion (succus entericus). The functions of albumin in the body are especially to build up the muscular tissue, to determine the absorption of oxygen, provide heat and energy; and if the starches, sugars, and fats are deficient in the food, it can be converted into fat. It is not completely oxidized in the body, but is excreted by the kidneys in the form of urea, which on exposure to air, as is very evident in most stables, is rapidly converted into carbonate of ammonia. If given in excess it does not seem to be stored up in the body for future use in the way that the fats are, but rather tends to produce disease. The proteid is the only organic compound in the food con taining nitrogen.
The second of the proximate principles con sists of the fats and hydrocarbons. They consist of carbon, oxygen, and hydrogen in the proportion of In true hydrocarbons there is no oxygen. The fats are compounds of glycerine with the fatty acids (oleic, margaric, and palmitic). Their functions are to repair and renew fatty tissues, and they yield energy and heat. They cannot be converted, so far as is known, into proteids as they do not contain the necessary chemical elements. Their pass age through the body is as follows. They are unacted upon in the mouth or the stomach. On leaving the stomach for the small intestine they are immediately met by the flow of bile from the liver, and with the help of the bile they form an emulsion which is capable of absorption by the lacteals, and so reach the blood. Fat is also acted upon and rendered absorbable by steapsin contained in pancreatic secretion. As has been mentioned, they give heat and energy, repair and renew the fatty tissues, and are completely oxidized into carbonic acid and water, in which forms they are excreted from the body. If given in excess they are stored up for future use, especially in the form of glycogen in the liver and as fat throughout the greater portion of the body. An excess of fatty food does not produce any thing worse than a want of condition.
The third of the proximate principles is the carbohydrates represented by the starches and sugars. These consist of the same chemical elements as the fats, namely, carbon, oxygen, and hydrogen, but in this case the hydrogen and oxygen are always in the proportion to form water Thus starch has the chemical composition cane sugar and grape sugar - The carbohydrates constitute the bulk of nearly all natural foods. In their passage through the body the starches are acted upon in the mouth by ptyalin, a ferment contained in the saliva, and are more or less, according to the length of time passed in the mouth and the amount of saliva secreted, converted into glucose or dextrose, otherwise known as grape sugar. The sugars are merely more or less dissolved by the saliva. There is no action on either the starches or sugars in the stomach. On reaching the small bowel they meet with the secretion of the pancreas, whose starch-digesting ferment" amylopsin" completes the conversion of the starches into sugar. This on passing into the blood is carried along to the liver, where it is retained as glycogen, to be supplied to the needs of the body as required. The functions of the carbohydrates are to supply heat and energy. They are unable to form proteids, but they can be converted into fat, indeed it is probable that the most of the body fat is derived from the carbohydrates. Like the fats they are completely oxidized in the system and leave the body in the form of carbon dioxide and water.
The fourth proximate principle consists of cellulose and woody fibre or lignin, which form the framework of plants. They are true carbo hydrates and have the same chemical composi tion as sugar, but are classed separately because they are supposed to be of no nutritive value. Not that there is no digestion or solution of cellulose, but because the energy required to digest it is equal to the energy derived from it after digestion. The general opinion, however, amongst veterinarians is that in cattle at any rate there is a nutritive value in cellulose. Amongst the constituents consisting of carbon, oxygen, and hydrogen should also be mentioned the various vegetable acids, which are very useful in stimulating digestion.
The inorganic portion of the food consists of the mineral salts, of which perhaps common salt or sodium chloride is the most important to the adult animal. It not only assists in keeping in solution the globulins of the blood, but it is the source of the hydrochloric acid in the gastric juice which materially aids the conversion of the insoluble proteid in the stomach into the soluble peptone.
The complete withholding of common salt from food will cause the death of the animal from starvation, owing to the proteid matter not being dissolved. Common salt does not exist in sufficient quantity in the natural foods of herbivora for hard-working horses or heavily milking cows. To these animals, therefore, an addition should be made to the food of common salt or in the form of rock salt in the manger. Phosphates, calcium, potassium, sodium, mag nesium, and iron salts are all essential to the repair and growth of different parts of the body. The phosphates of lime, potash, and magnesium go to the formation of bone and also nervous tissue. Muscular tissue is also rich in potash. Iron helps to form the hfflmoglobin of the blood.
" The last proximate principle is water, and when we remember that almost two-thirds of the body is composed of water there is no difficulty in comprehending its necessity as a food. Its use in the body is for the solution and conveyance of the food to different parts of the system, the excretion of effete products, the equalization of heat by evaporation both from lungs and skin, as well as the regulation of all the chemical and mechanical functions of the body" (Notter and Firth).
A complete food, therefore, must consist of fats, carbohydrates, salts and water. No two cereals contain these constituents in the same amount or proportion. Thus, peas and beans contain a high percentage of proteid, linseed contains a high percentage of fat, while maize contains a high percentage of soluble carbohydrate, so one has next to consider the" nutritive relation" or the proportion in which the proximate principles of food are arranged towards each other, and what are the best ratios or proportions of the albuminoids (proteids), carbohydrates, fats, and cellulose for a food to supply its highest economic value, while at the same time sustaining the animal in perfect health.
In the case of carriage horses and hunters it is more a matter of health and condition without regard to cost, but in the case of large horse owners such as municipalities, large carriers or railway companies, it is a question of how to get the work done by the cheapest method of feeding consistent with the good health of the horses. I am acquainted with veterinary surgeons who in the first year of their appointment have saved for their em ployers more than the whole of their salary, not only without the horses suffering in the least, but with an actual improvement in health as shown by the number of working days. Let us then try to understand what is meant by the nutritive relation or ratios of food, which seems to be something of a" pons asinorum" to the beginner, though it is really very simple.
There are three ratios to be considered: the first known as the nitrogenous ratio, the second the fatty ratio, and the third the complete nutritive ratio.
The nitrogenous ratio means the ratio or proportion of digestible albuminoids to the digestible non-albuminoids, cellulose and salts not being included. In other words, it is the proportion of the proteid to the fats and carbohydrates. Perhaps the following table or classification of the constituents of food will enable this to be more easily understood.
In order to arrive at this, it is necessary to know the percentage composition of the food, which is ascertained by taking the mean of a large number of chemical analyses. For instance, take the analysis of oats.
This means that for every one part of nitrogenous matter there are 5.2 parts of non-nitrogenous matter. By this calculation, therefore, the nitrogenous ratio of oats would be said to be 1: 5.2. This is not quite correct, owing to the fact that the nutritive value of fats is nearly 24 times the value of carbohydrates, and it is necessary in order to be correct to reduce these two to the same value. What has to be done, therefore, is to multiply the percentage of fats by 24.
Substitutional Dieting. There are generally various cereals on the market which by substi tuting for the whole or a portion of the oats will give a quite healthy mixture and capable in the case of draught horses of giving the necessary amount of work, and it is the business of the food expert to discover the cheapest food capable of fulfilling the required conditions. This will vary according to the markets. Some times oats are relatively higher in price than maize or barley. Sometimes a few beans may with advantage form a part of a horse's ration, but beans being highly nitrogenous would unbalance the food unless given in small quan tity or some substitute found containing less nitrogen. It is a rather interesting study to watch the markets and try and work out a well-balanced food at the lowest possible cost. By a well-balanced food is meant a food in which the proximate principles are in their proper proportion, i.e. where the ratios work out cor rectly. I have worked out a diet (see below) as an example which usually is not an expensive one comparatively, and which I have found a singularly healthy one. With the necessary care in feeding and watering to which I shall refer later, it has almost abolished colic, enteritis, and that most unsatisfactory mischief known as twisted colon, which I am convinced is due in most cases to errors of feeding, more particularly with regard to the balance of the food. It consists of the following mixture: 6 lbs. of oats, 6 lbs. of maize, 3 lbs. of beans, 2 lbs. of bran, and 13 lbs. of hay.
In the summer time, when less food is required to keep up the body temperature, a portion or even the whole of the beans may be omitted.
In this food for cart-horses I advocate 10 lbs. of hay given as chaff amongst the corn ration and 3 lbs. of long hay in the rack at night for the following reasons. A horse is almost com pelled to grind this food, he cannot bolt it. Many horses prefer corn to hay, provided both are of good quality, and will eat the whole of the corn before touching the hay and then perhaps not eat enough hay to balance the corn, or if horses are not allowed a sufficient time for their meal they have not time to eat the hay after finishing the corn. (The man who comes late in the morning is often respon sible for this.) But by mixing it in this way the horse has always a fairly balanced ration, and the 3 lbs. of hay at night in the rack will give him something to play with during the night if of a wakeful disposition and prevent him eating his bedding. Working cart-horses should be allowed at least two hours for break fast before commencing work and not less than one and a half hours for the mid-day meal. They should be fed four times a day, the last feed as late as convenient at night. Ten pounds weight of food is too much to put into a horse's small stomach at once. That is what three meals a day means, and is the cause of a good deal of stomach and bowel trouble. Food may be damped to prevent a horse blowing it out of the manger. It should never be made very wet except in the case of a bran or linseed mash. Very wet food is a temptation to the horse to bolt his food. Grinding the food is necessary to excite salivation, without which the starches are not acted on in the mouth. Boiled food is only permissible to old horses with defective teeth or some such special reason, as when colts have tender gums from teething. There are two useful rules to remember, in working out a mixed chop for horses, which may save a good deal of calculation and worry. Never include in a suggested food more than 3 lbs, of peas or beans per diem or there is difficulty in balancing the food, and bowel affections are the result; and never let your hay fall below the proportion of as three is to four of corn in weight for the same reason.
It will have been noticed that at the end of the table giving a suggested mixed chop for heavy horses I have also shown the percentage digested of each of the proximate principles. If the absolutely correct ratios are desired, the percentage digested must be taken into con sideration, but it complicates the calculation and in my opinion, at any rate, is unnecessary. I have tried a number of mixed foods and worked them out according to the percentage digested, and found the difference was only a matter of one or two decimals, which is of no importance in the composition of a diet.
The Watering of Horses.Horses should always be watered before being fed. A con siderable quantity of fluid is required for the production of gastric juice, and watering before feeding helps this process. Watering after feeding not only dilutes the gastric juice and so weakens its action, but will also wash through the stomach a quantity of undigested food, the nutritive value of which is thus lost even if nothing worse in the form of bowel trouble occurs. There is some prejudice against giving a horse water when he is sweating. It is an overrated prejudice, but where such exists it is surely not a difficult matter to take the chill off the water, which abolishes the objection.
Digestibility of Foods.Every natural food contains some matter which is absolutely indi gestible; but more than this, every food has a portion of that which is digestible unacted upon, and which is excreted from the system without undergoing absorption. Our knowledge of the digestibility of food by farm animals is almost entirely derived from German investigators, and for those who would wish to refer further to the subject I would recommend the translation of the German work of Professor Emil Wolf by H. M. Cousins, M.A., entitled Farm Foods.
The general method of investigation has been to supply an animal with weighed quantities of food, the composition of which has been as certained by chemical analysis. During this experimental diet the solid excrements are collected and weighed, and finally analysed by the same chemical methods previously applied to the food. Subject to certain small corrections for intestinal secretions, we obtain by this plan the amount of each constituent of the food which has passed through the animal unabsorbed, and, by difference, the amount digested.
The amount of food digested seems not to differ whether the animal is in an emaciated state, requiring all the nourishment possible, or whether it is in a condition of being overfed. If a piece of meat is placed in a large amount of gastric juice no more of it is digested than if placed in what is only just a sufficiency.
The proportion of each constituent digested for 100 parts supplied is known as the digestive coefficient. The mean coefficient of digesti bility of proteids in the horse is 69, of fats 59, and of carbohydrates 68. This means that of every hundred parts of each of these substances the horse can digest of the first, of the second, and of the third. The ox digests a greater percentage than the horse. Hard work with exhaustion seems to diminish the co efficient of digestion.
In hay the digestibility varies according to the ripeness of the grasses when cut. The young plant is always more digestible than the mature one, and in overgot or overripe ryegrass hay for example the amount of soluble carbo hydrates has been so greatly transformed into cellulose as to render it a most indigestible food. Boiling the food does not increase the coefficient of digestion in the least but rather decreases it.
It is also generally accepted, though not universally, that in a mixed food the digesti bility of each food is increased by the admixture of the other. That is to say, supposing a horse is thrown off work for some time and only hay and water given, which is sufficient for a subsist ence diet, it would actually be cheaper to add a couple of pounds of oats per day, because by so doing the animal would extract so much greater nourishment from the hay. Further experiments, however, are required on this subject before one can be dogmatic upon it.
Heat and Energy Production.I have now to say a few words on the heat- and energy-produc ing power of foods. This has been calculated especially by the researches of the late Dr. Joule of Manchester. It is a chemical law that the complete combustion of a certain amount of material of any description, whether coal in a fire or food in the body, always gives off a definite amount of heat; whether the com bustion be slow or quick the same amount of heat is given off in the aggregate. Joule proved that heat can be converted into energy without loss, and he found from an elaborate series of experiments that the amount of heat required to raise 1 lb. weight of water through one degree Fahrenheit, i.e. to raise the temperature from say 39° F. to 40° F. for example would, if converted into energy, be sufficient to lift 772 lbs. weight one foot in height.
The amount of heat necessary to raise 1 lb. of water one degree higher in temperature is known as the heat unit or calorie, and the mechanical equivalent of one degree of heat in the Fahrenheit scale is said to be 772 foot pounds.
Joule's experiments prove that 1 oz. of albumin, of which only is oxidized in the body, yields nearly 170 foot tons of potential energy.
One ounce of fat oxidized in the system yields 378 foot tons of potential energy.
One ounce of starch oxidized in the system yields 138 foot tons of potential energy.
One ounce of grape sugar oxidized in the system yields 124 foot tons of potential energy.
These calculations, so far as the lower animals are concerned, are of more academic interest than practical importance; so much energy is required in keeping up the body temperature and in the movements of the heart, lungs, bowels, and general animal metabolism that it is calculated that only about + of the food con sumed is available for work. For example, the horse requires food sufficient to produce 21, 000 foot tons of energy for the processes of the body alone, and if you calculate that a horse's day's work should approximate to 3000 foot tons, you must then give him an amount of food sufficient to produce 24, 000 foot tons of energy.
It will be noticed in the above statements that the term" potential energy" is used. Perhaps a few words in explanation may be useful. Energy means the power of producing movement, or so far as we are concerned the power of producing work. It is divided into two kinds, potential and kinetic. Potential energy is energy which is stored up for future use and is not being expended in work at the moment. One example of potential energy usually given is poising a stone above the head; release the stone and the potential energy becomes converted into kinetic energy or actual movement. This is, I believe, one of Newton's own examples, but I must confess it always seems to me a better example of gravity or the attraction of bodies to each other. Another example is, if you wind up a watch spring, you can do it so carefully that when wound it will remain still, but touch the watch spring with a needle and it will commence to work, and thus the potential energy becomes converted into kinetic energy; so, fat may be stored up in the body and give to that body potential energy, which, if you work the animal on an insufficient supply of food, will be used up by the body to produce the kinetic energy or vis viva.
The kinetic energy of an animal is represented by (1) his maintenance work, i.e. the work expended in breathing, circulation, and the pro duction of animal heat, and (2) by the external work he does, as moving the limbs, drawing a load, and carrying himself. This energy is produced by the breaking down of the proto plasm of the cells and the combustion of food materials.
Various Articles used as Food Grass Grass, the natural food of herbivora, is made up of a large number of different species of Graminacew, and included amongst the grasses but usually referred to as" artificial grasses" are the clover, vetches, sainfoin, and lucerne, belonging to the natural order Leguminosx. The grasses vary considerably in their feeding value and are divided into three groups, namely:" good, "" indifferent, " and" bad or useless." Roughly speaking, ' the composition of grass is as follows: Water . . . . SO per cent.
Proteid . . . 3 to 5 per cent.
Fats. . . 1 per cent.
Carbohydrates . . 10 to 12 per cent.
Cellulose . . 3 to 12 per cent.
Salts. . . 2 per cent.
Grass itself is quite sufficient to keep a horse in health provided that no hard work is required, but the quantity of water produces a condition known as hydreemia or excess of water in the blood, a condition quite healthy but not favourable for work. It will be noticed that when a horse comes up from grass, unless in a very dry season, he will not touch water for two or three days, and it is for this reason that a watery purge is valuable before putting him to work. Otherwise" filled legs, " if nothing worse, is apt to supervene.
Meadow Foxtail (Alopecurus pratensis). One of the earliest grasses, flowering in April, and one of the best, especially for pastures. If sown in meadows it has usually lost its seed before the time for mowing, but even then it loses less of its nutriment than most of the other grasses. Either nitrate of soda or sulphate of ammonia has a very beneficial effect on its growth. Meadow foxtail is three years before attaining its full growth.
Timothy or Meadow Cat's-tail (Phleum pra tense). A hardy good grass but late, flowering in July; attains its greatest height and produc tiveness in the first year after being sown. All good meadow hay should have a fair proportion of timothy. This grass might be mistaken for foxtail, but is easily distinguishable by the absence of the hairy awns which are quite a feature of the foxtail.
Crested Dog's-tall (Cynosures cristatus). A good grass, which does not, however, add great weight to the hay. It has a rather small flowering head compared with the two previous grasses, but is good both for pastures and hay. It responds better to nitrate of soda than to sulphate of ammonia.
Fescues. The Fescues are all classed as good grasses with the exception, perhaps, of the Sheep's Fescue (Festuca ovina), which is so short that it is useless for hay, as it is too short to be mown either with a machine or a scythe.
Rye Grasses (Lolium italicum and Lolium perenne). The Italian ryegrass is a biennial, i.e. it only lasts for two years, and should not be sown in pastures. It is a good grass, but requires to be cut early. In Scotland it is grown as a separate crop and is estimated very highly. In other parts of the country, as a rule, it is sown along with red clover and is commonly known as first crop. There is no better hay than clover and ryegrass, assuming, of course, that it is well got. Both this grass and the red clover flower a second time in the same season and so produce two crops of hay, hence the names first and second crop. The Lolium perenne or perennial ryegrass is not perennial on sandy or very light soils, but otherwise is correctly named, and is one of the very best of grasses. In some parts grown as a separate crop, it is generally to be seen and should be present in all good meadow hay. The two grasses can easily be distinguished from each other by the presence of the hairs or awns on the Italian variety which are absent in the perennial.
The Artificial Grasses. Clover, lucerne, vetches, and sainfoin belong to the natural order Leguminosw. They are all good. Some of the clovers are perennial, but the red clover grown with ryegrass is at most biennial, as it is incapable of self - fertilization, depending for this process on the bee carrying the pollen to the female flowers. There is, however, a peren nial red clover known as cow grass or zigzag clover, grown principally in the south of England, where it seems to be highly thought of. The white or Dutch clover and the Alsike are both perennial. Neither horses nor cattle seem to be specially fond of these varieties, although their nutritive value is quite good. Lucerne, a very ancient plant described by long before the Christian era, is a valuable forage plant, but is not much grown in this country, as it requires a dry climate and a dry soil. It is usually eaten green in this country. It is an excellent forage grass and produces three or four cuttings in the year. It is imported into this country as hay from the South American states under the name of Alfalfa.
Vetches, a good food when young, but indi gestible when they commence to go yellow at the roots, are eaten green and usually sown with an admixture of oats round the headlands of cornfields.
Sainfoin is also a valuable forage plant, largely grown in the south of England, and also eaten green or made into hay.
Cocksfoot (Dactylis glomerata). This grass has a very wide distribution, is very hardy, and usually classed as a good grass. This view, however, requires some qualification. It is a good grass if grown alone and cut early, but usually it is sown with the late meadow grasses, and being an early flowering grass it has not only lost its seeds, but in the stems the digest ible carbohydrates to a remarkable extent become converted into cellulose and even lignin, an advanced stage of cellulose which is absolutely indigestible. From a farmer's point of view also it is not too desirable, as its roots spread in the form of a cushion and interfere with the full growth of the adjoining grasses.
Sweet Scented Vernal (Anthoxanthum odor atum). This is the grass which gives the pleasant smell to meadow hay. It has no smell when green but only when dried. It is a moderate grass from a nutritive point of view, and as it flowers early it has frequently lost its seeds before being harvested. The essential oil is supposed to act as a condiment, and in some parts of Europe is extracted for the manufacture of scent.
Yellow Oat Grass (Avena flavescens). I am inclined to rate this grass somewhat higher than most authorities, and I have no objection to quite a fair quantity of it in a sample of hay.
Fiorin or Creeping Bent Grass (Agrostis alba) comes rather low down amongst the moderate grasses.
Poas.There is a considerable number of varieties of Poa all more or less resembling each other. They are only regarded as very moderate grasses, although personally I prefer them to florin.
Yorkshire Fog or Woolly Soft Grass (Holcus lanatus). This is a grass which one sees in far too great quantity in most samples of meadow hay. It is a useless grass, although in Australia it was for a time rather highly thought of, but I believe that now they are coming to the same conclusion as authorities in this country.
The other grasses in the list classed as useless need not be further alluded to. They are all found more or less in inferior samples of meadow hay.
To all interested who may wish to recognize these and other grasses at sight I would strongly recommend the purchase from Messrs. Sutton, of Reading, or some other seed - growers of a box containing samples of the different grasses, which can be had for a few shillings. It is very much easier to learn them from these samples, which are labelled, than from any book plates.
Hay Hay is usually divided into three classes, Upland, Meadow, and Water Meadow, but gener ally speaking, I think, a better division is that commercially adopted, i.e. the division into First Crop and Meadow Hay.
The first crop consists almost entirely of Italian ryegrass and red clover. It usually follows an oat, wheat, or barley crop and is very good, especially for milch cattle. It has not been considered suitable for racehorses or hunters, owing to its larger proportion of cellulose than in hay containing the permanent grasses. At one time no stud groom would have used this hay for galloping horses, but this prejudice is not so pronounced as it used to be, and now in many racing and hunting stables it is freely used. This ryegrass and clover hay produces a good aftermath or second crop, as both the ryegrass and the clover flower a second time. In the case of the permanent grasses many of them do not flower a second time, with the result that the aftermath of meadow hay consists almost entirely of the stems and leaves of the grasses, and the absence of the flowering heads detracts very seriously from the nutritive value of the hay.
How to make good Hay.In grass cut too young, i.e. before it flowers, much of the nourishment is in the roots, and the nitrogenous portion existing in the stem consists only of amides. It has not yet become a true proteid, and amides can only be converted into heat and energy. The difficulty of saving such hay, also, would be very great and the shrinkage excessive owing to the large amount of water it contains. Young grass cut at the proper time, i.e. after flowering but before the pollen begins to fall, contains a great deal more nutriment than in the case of grass cut late. When the grass has done growing the soluble carbohydrates (starches and sugars) in the stem become converted into cellulose to build up and strengthen the structure of the stem; cellulose is indigestible fibre, and the indigestible fibre of young hay is therefore much less than in hay cut late. Old grasses have well-developed seeds. and the nutriment, especially the proteid matter which was originally in the stem, will have passed into the seeds, and when the seeds fall this most valuable portion of the food is lost altogether. By letting the flowering heads ripen and fall, a considerable amount of the nitrogenous matter extracted from the stalks will be lost. Of course, the barometer has always something to say as to the exact day when one can commence cutting hay, but there is considerable difference in the feeding value of hay cut from old grass. Many farmers, particularly those who do not consume their own hay, allow it to get too ripe, because they get, a greater weight per acre, and the general public is too ignorant to appreciate the differ ence in value. Hay made from old grass also often contains more weeds, such as docks and sorrel. Often in the market one can see two loads of hay selling at about the same price per ton where the nutritive value of the one is 20 or 30 per cent more than the other. Hay as made in England should never be eaten until it has been at least three months in the stack. It takes nearly this time before the temperature of the centre of a stack is reduced to that of the surrounding atmosphere, owing to fermen tative changes, and if used before is a prolific cause of digestive trouble.
Good hay should have a rather greenish tint, hard long stems, clean, fresh, and possessing the well-known aroma. Meadow hay should have a considerable variety of good grasses and an abundance of flowering heads.
When hay is stacked a bacterial fermentation takes place, producing heat and a change of a portion of the starchy material into sugar. If there is too much moisture left in the stems when stacked, i.e. if stacked before it is ready, this fermentation is carried a stage further, the hay becomes dark in colour and the sugars are converted into acetic acid, or the stack may even take fire from spontaneous combustion. Horses will often for a while eat readily of this dark-coloured or mow-burnt hay if the process has not gone too far, but good buyers will reject it, as it is a prolific cause of diuresis (profuse staling) and excessive thirst, followed by want of condition and emaciation.
Mouldy hay is an entirely different condition from mow-burnt hay and is due to a fungus (Penicillium glaucum) which finds a. congenial habitat on hay which has received a shower of rain during the process of housing or stacking.
That hay which is the cheapest to make is always the best, by which I mean the hay which has required the least turning over, the least labour. Hay that has been more than three or four days between cutting and housing and exposed to bad weather has lost a con siderable amount of its soluble carbohydrates and loses its crispness. It is usually darker in colour, does not rustle when handled, but feels soft and woolly. On the other hand, hay left too long in the sun becomes bleached, brittle, and dusty, and loses its flavour and quality.
The Grains The grains are really not the natural food of herbivora, but are necessary when work is required. Hay of itself will only give little over a subsistence diet, i.e. the amount of nourishment necessary to subsist without any extra exertion.
Oats. Of the grains the most valuable and widely used is undoubtedly oats. There are numerous varieties of oats, the commonest being the white, yellow polands, tawny, black tartary, and crosses between the white and black oats such as the tartar kings and storm kings. The white oats and the crosses are the commonest all over England and Scotland, while the black oats are mostly grown in Ireland. There is very little to choose between equally good samples. The true test is the amount of oatmeal which a sample will yield, but generally speaking a good sample should be large in the grain, short, plump, thin in the skin or husk, bright in colour, and feel hard like small pebbles when handled. They should weigh not less than 40 lbs. to the bushel. Oats vary some what in their chemical composition, but the following may be taken as the analysis of an average sample: Oats are divided into new and old. They are classed as new until they are a year old. It is unnecessary for oats to be a year old before being used, but it is a very good rule never to allow them to be eaten in the year they are grown. As soon as January sets in they may be eaten with impunity.
There has been some. controversy as to the economy of crushing oats. The late Professor Pritchard contended that it was unnecessary. He held the view that the horse had a splendid grinding machine in his mouth, and that even in case of a horse bolting his oats, the heat and moisture of the stomach were sufficient to burst the grain and enable the animal to extract all the nourishment. This is not correct. I tested it by using the dung of a horse that habitually bolted his oats as a manure for a flower garden, and grew quite a considerable quantity of oats amongst the flowers. But while I contend it is an economy to crush oats I never advocate the purchasing of crushed oats from a dealer, for the following reasons. A dealer will natur ally not crush his best oats, a sample of light oats is not so easy to distinguish when crushed, and in the case of a dishonest dealer such as unfortunately does occasionally exist, there may even be added to the sample the husks left in the process of preparing oatmeal. It is a somewhat informing study to examine the proportion of empty oat husks in many samples of crushed oats bought from dealers. Of course I do not say this is general, but I do say it occurs sufficiently often to be worth looking into.
New oats are occasionally thrashed before they have been long in the stack, and are then kiln dried and rushed on to the market before the price comes down. They can be distinguished by being a little puckered in the husk from the heat, from being softer than the old, and from having, mingled with the earthy smell of new oats, a slight" sulphury" odour. Old oats as a rule from attrition and dryness have lost their beards or tips. This should not be confounded with what is known as clipped oats, in which the ends have been taken off by machinery, leaving them quite square at the pointed end. This process is adapted parti cularly with Canadian and New Zealand oats, which are imported into this country in large quantities. They are very light oats, often weighing not more than 35 lbs. to the bushel. They are generally well got. and with the excep tion of being badly fed, a good oat, but should always be fed by weight or the animal will go short of his supposed ration. When oats have suffered from over - heating in the stack, a condition comparable to mowburnt hay, they become, except in the case of black oats, darker in colour, and are termed" foxy" from the char acteristic smell. These will produce the same effects in horses as mowburnt hay. In order to hide this condition they are often bleached by means of sulphur dioxide (doctored oats). This can be detected by rubbing a small sample between the palms of the hands, when the smell of the is easily discerned.
Good oats and hay, with an occasional bran and linseed mash, are a sufficient food to keep in health and condition all but those horses doing exceptionally hard work, and other grains are only substituted on the ground of economy.
Maize or Indian Corn.Maize is often called Indian corn and is largely grown in India, but the principal portion reaching this country comes either from Russia or America. The Russian grain is smaller and rounder compared with the American flat corn, and is mainly used for feeding poultry. It is the principal substi tute for oats, but is unsuitable for horses doing fast work, as although it has a fair proportion of proteid, it is exceptionally rich in carbo hydrates and is consequently rather fat-forming than muscle-producing. It is exceptionally poor in salts and is practically without lime. It should therefore not be used in great quantity to infoal mares, or to young growing stock requiring lime for the formation of bone. It will be remembered by those who had much experience of American horses, that many went lame if put to fast work for the first few months after their arrival in this country, from a form of ostitis or inflammation of the bones of the fore - legs, particularly due, in the opinion of many, to the softness of the bone from deficiency of lime salts, due to having been reared largely on maize. After a few months in this country, and being fed on oats, this tendency to lameness disappeared. For cart-horses maize may be substituted for oats to the extent of one-half the oat ration, but should always be crushed, or much of the hard grain will pass through the body without digestion. In South Africa maize is known as" mealies" and is extensively used as a horse food. As a food for cattle in the form of maize-meal it is exceedingly useful both for milk and fattening purposes, and it is a capital food for fattening pigs, though prac tically for the last fortnight of a pig's life oat meal should be given, when the flavour of the bacon is greatly improved.
Barley. When the market conditions are favourable barley may be substituted for oats. Mr. J. Malcolm, F.R.C.V.S., of Birmingham, who had exceptional experience in feeding cart horses, stated that he could find no difference between two stables in one of which barley had been substituted entirely for oats. My experience has not quite coincided with his. I have thought that after a few weeks' substitu tion it produced a certain amount of bowel trouble, due, as I considered, to the awns on the barley. Barley should be crushed, other wise with greedy feeders a proportion of the hard grain will pass through the body without digestion. It is an excellent food in the form of meal for either cattle, sheep, or pigs, and in the case of young colts two to four years old during the eruption of the molar teeth and consequent tenderness of the gums. It is quite easily assimilated when boiled. This is one of the few conditions when boiling of grain is permissible and indeed advisable.
Wheat.Wheat is an unfit food for horses, under any conditions, unless eaten green or baked into bread. It can produce tympany, laminitis, and stomach staggers. It is fortunate that its demand for human food is such as to preclude the probability of its use as a horse food. Damaged wheat is sometimes used for cattle, but with them, unless in very small quantity, is apt to produce impaction of the rumen. The percentage composition will show at once how difficult it is to balance a food if wheat forms one of the component parts, but it is the gluten of the wheat which forms a gummy mass in the stomach and especially is the cause of trouble.
Bran is the outer covering of the kernel of wheat, and is known as red or white bran, according to the colour of the wheat from which it is obtained. Commercially there are two kinds of bran, broad and fine. The broad bran with large flakes is the best, and lends itself least to adulteration. The best bran has a small amount of the flour adherent to it, but these small particles do not tend to form glutinous masses in the stomach as in the case of a feed of wheat, although large quantities of dry bran are not advisable. Two pounds of dry bran mixed with the other food is quite sufficient for a day's ration for either a horse or cow. Large quantities of dry bran have been blamed for the formation of calculi in the bowel, owing, it is said, to the quantity of salts, especially phos phates, which it contains. If, in addition to dry bran, the water in the district is very hard from the presence of lime salts, I am of opinion that the two together do constitute a danger.
There has been considerable controversy as to the value of bran as a food. F. Smith in his Veterinary Hygiene says it is useless, whereas experiments at the West of Scotland Agricul tural Society point to its being highly valuable. It is a very healthy food for sick animals in the form of a mash made with boiling water and then allowed to cool slowly, and has a somewhat laxative effect due, according to some, to the irritating effect of the bran on the bowels, but according to later opinion, due to the magnesium constituent of the bran (Pbytin). It is also a good food for young animals from its digesti bility and richness in phosphates, but it should be remembered in this connection that the phosphate is that of magnesium, and that bran Bran lends itself to adulteration principally from the addition of sand or sawdust or both. By stirring up some bran and water the sand can be detected by immediately falling to the bottom, whereas sawdust will float after the bran has settled down. Good bran should have a sweet and pleasant smell. Sometimes one notices an oily smell, in which case it has prob ably been mixed with some bran which has been used for cleaning machinery. This probably would do a horse no harm if he would eat it, but he wont.
Beans. Horse beans (Faba vulgaris) are largely grown in the British Isles, and are also imported in large quantities from abroad, especially the East. They belong to the natural order Leguminos, all of which order are very rich in proteids, and generally speaking, with the remarkable exception of Soya beans, very poor in fats. Three lbs. weight per day is the maximum quantity permissible for either horses or. cattle. They may be given whole or split to horses mixed with other food, and in the form of meal to cattle. English beans are much to be preferred to foreign. Foreign beans are often a distinct danger from the presence of small pebbles amongst them, due to the method of threshing the beans in the open on the sandy soil, and then shaking in a large meshed sieve or riddle which gets rid of most of the sand but leaves the small stones. These are a distinct danger from two reasons, firstly, horses' teeth are often split from trying to grind the small stones, and secondly, from their liability to form a nucleus for calculi formation in the large bowels. Foreign beans are also often affected by the weevil, a small insect, quite visible in size. Indeed, some weevils reach up to of an inch in length. They bore into the bean, and may destroy the whole of the inside, leaving nothing but the shell. Their presence is recognized by the existence of a small hole about the size of a pinhead. They are ex tremely difficult to get rid of. You cannot drown them. Beans affected with weevil may be left under water all night and the weevil is still alive. Indeed the only method of dealing with weevily beans is to grind the bean into meal. ..
Peas.The variety used for feeding the larger animals is principally the white pea, Pisum arvense. Peas are not largely grown in the British Isles, but are principally imported from Canada and the East, especially India. The Canadian peas are large and in every way much the best of the foreign peas. Indian peas are smaller, and can be recognized by the presence, in almost every sample, of a number of small brown peas (Pisum sativum). Nearly every sample of Indian peas contains a large quantity of sand, and they are an unsafe food for horses unless first dealt with by a powerful dust extractor. I have known as much as 25 per cent of Indian peas to consist of sand. In other words, for every four sacks of Indian peas you are probably buying one of sand.
Peas are not so good as beans for horses. being less easily digested and productive of tympany. For cattle, in the form of meal, they may be used up to 2 lbs. weight per day. Peas, like beans, are also very subject to attacks of weevil.
Soya Beans Beans.These beans, ivory coloured and looking like ovoid peas, have a most extraordinary percentage composition, containing as much as 40 per cent of proteid and 25 per cent of fat. They are largely imported from Japan and Manchuria for the purpose of extracting the oil for soap making, after which they are pressed into a cake. They have also been crushed and sold as Soya bean meal or cake. It is possible that ex periments will show that if properly balanced by the admixture of other foods, a valuable feeding stuff may result, but until this is done they can only be considered as a very dangerous food, and one that should only be given in the smallest quantity, certainly not more than 1 lb. weight per day.
Gram (Cicer arietinum). Gram, a grain of the leguminous order, is grown and largely used in India. It is a brown wrinkled kind of pea, and its analysis is very similar to beans. It has been for some years largely imported into this country, and is used crushed as a substitute for beans and in the same quantity. Provided it is only used in limited quantity, it seems to have no ill effects, but to be quite a good food.
Rye.Rye is only grown in certain parts of the British Isles, and is not largely used as a food. It is very subject to the attack of a fungus known as Ergot (Claviceps purpurea), and when affected with this should never be used to parturient animals, as the action of ergot of rye upon the uterus is apt to produce abortion.
Linseed. Linseed is the seed of the flax plant, and is a valuable food for both sick and healthy animals. It should never be given dry, as in this case many grains will pass through the body without solution. It may be given mixed with bran or other food either boiled, scalded, or stewed. Stewing is the best method of dealing with linseed, as here the grains are not burst so much as in boiling, and are conse quently more palatable to the animal. It forms the bulk of most of the calf meals, and in the case of an orphan foal oil-dust gruel, i.e. gruel from ground linseed from which the bulk of the oil has been expressed, can be used as a substitute for milk, though not entirely, owing to its laxative properties.
The following is the analysis of linseed: Hand - Feeding a Foal. Here, perhaps, I might interpolate that the common method of feeding an orphan foal is to take cow's milk, add boiling water until the temperature of the mixture is 100° F., and a teaspoonful of sugar to the pint of milk. In this connection it should be remembered that cane sugar should not be used; lactose, of course, is ideal, but its expense is prohibitive. Brewers' sugar (glucose) acts very well, and is easily assimilated by the young animal.
Poisonous Grain, etc.
There are poisonous grains which only require a few words, as they are sufficiently understood by grain merchants in this country to prevent their importation in large quantity unless as an adulteration to some other ground food or meals.
Java Beans.These are the most dangerous beans. They are flat and shining and may be either a shade of pink, purple, or marbled. They are extremely poisonous, and if given in sufficient quantity can cause death within half an hour, due to the production of hydrocyanic acid from the action of the gastric juice on the bean by its moisture and warmth. The HCN is really produced by the fermentation of a glucoside amygdalin. There is not much danger of the importation of these beans, as their properties are well known.
The Mutter Pea or Vetch and the Riga or Pea.These were imported in large quantities a few years ago, and produced suddenly, after being fed to horses for several weeks, most alarming symptoms, and indeed occasionally fatal results. In the stable the horse is apparently healthy, but when put to work or exertion of any kind an appalling dyspnea or difficulty of breathing sets in, accompanied by not exactly a roaring, but rather squealing sound which may result in suffocation and death in a few minutes. It is due to a paralysis of the muscles of the larynx or entrance to the windpipe, and is of a nature very similar to that causing roaring in horses, with this remarkable exception — that roaring is an incurable disease which tends to go worse. I have never known a case of even the most severe attack of mutter poisoning which, unless death occurred as previously mentioned, did not make a complete recovery in the course of a few months. It is said that by boiling the mutters before use the poisonous property, a toxin called lathyrin, is destroyed.
Yew. The old leaves of the yew tree, but not the seeds, are well recognized as poisonous. There are practically no symptoms in yew poisoning, collapse and death with the presence of the leaves in the stomach being all there is to be seen.
Potatoes. Potatoes in a certain stage of putrefaction or disease undoubtedly at times develop a poison. Not much is understabd at present of the cause, but pigs, which are often the recipients of diseased or brown and rotten potatoes, are often killed by them, the only post-mortem appearance being a slight conges tion of the stomach. It is apparently a species of ptomaine poisoning.
Feeding Cakes These are highly concentrated foods pro duced from various seeds by the removal of a portion of the oil, the residue being pressed into cake. They are prepared by" hot pres sure, "" cold pressure, " or by the action of" solvents" which are afterwards recovered to be used again. Generally speaking, cakes are sold guaranteed to contain a certain per centage of oil, usually round about 10 per cent, with the exception of the undecorticated cotton cake which often contains no more than 6 per cent or 7 per cent of oil.
The most valuable feeding-cake is the linseed cake. It is the most digestible, and has slightly laxative properties, and can be given to animals of any age. Though the cakes are not con sidered a horse food, and are principally used for cattle and sheep, the linseed cake ground into dust is largely used for fattening horses for show purposes.
There is also a number of compound or mixed cakes—proprietary cakes made by different firms, many of them very good, but, of course, of varying composition, and more or less secret, and often containing a spice which perhaps may add to the amount digested.
2. If a less valuable ingredient has been substituted.
3. If it be coloured, powdered, or polished with intent to deceive or to make the article appear of better quality than it really is.
4. If it be a substitute or imitation of a genuine article, and offered under the name of that article.
An example of the first - named condition is occasionally found in crushed oats from which a portion of the meal has been extracted during the process of crushing, the result being exactly as if some empty oat husks had been added. Perhaps the commonest adulteration of cakes is to mix a cheaper cake with a more valuable one, thus, rape is often mixed with linseed. Except that it is fraud this is not harmful, but cakes are also mixed with deleterious materials, the refuse husks of the castor or even the croton bean being sometimes found, particularly in the cotton cakes. I have also found quantities of chopped string and sacking as an adultera tion. The detection of these frauds is not always very easy owing to the finely-powdered condition of the adulterant in the mixture. A magnifying glass is useful, but often nothing short of a microscopical examination by an expert, who can detect from the appearance of the starch grains the plant from which they f r e are derived, is sufficient to determine what the adulterant is.
The principal roots and allied foods are turnips, swedes, mangel - wurzel, kohlrabi, cabbage, potatoes, and carrots. They are especially winter and early spring diets, and are very useful as supplying fresh vegetable material until grass time. They consist of 80 per cent to 90 per cent of water, the balance being made up mostly of carbohydrate.
Turnips and swedes are used for horses, cattle, and sheep. They may be given whole, but should never be given sliced to horses or cattle, the top slice, particularly in the case of cattle, being a frequent cause of choking. A cow does very little grinding of her food when she is hungry, but bolts it and depends upon chewing her cud for proper mastication. The top slice often becomes fixed in the throat or upper portion of the oesophagus, where it is very difficult to deal with, the sharp edge injuring and sometimes even penetrating the delicate wall of the cesophagus with fatal results. They should always either be cut into fingers or pulped. A cow or bullock may be allowed up to half a hundredweight of turnips per day.
is a species of beet, and is better buried in the ground until the early spring when the turnips are finished, as there is a carbo hydrate named pectin which becomes changed into a more digestible sugar in the course of two or three months after pulling. Mangels (or mangolds) should only be used very sparingly to sheep, as in them they are apt to produce urinary disease if given in quantity.
and cabbage are quite healthy foods and do not tend to taint the milk to the extent that turnips do, though turnips do not taint the milk much if they are given after or during the process of milking, and not shortly before.
Potatoes are not a good horse food in any quantity, and unless given boiled are apt to produce purging and colicky pains. A few raw sliced potatoes to a horse sick from indigestion are often very useful, they stimulate the salivary glands and sweeten a foul mouth, but half a dozen are quite sufficient, more are likely to do harm. Cooked they may be used in fair quantity for cattle, but the small unmarketable potatoes are best used for feeding pigs. Un cooked potatoes should never be given whole to either cattle or horses. They are a not uncommon cause of choking in both.
Carrots are a most valuable food for either horses or cattle, but are usually too expensive to give to the latter. They contain more digestible proteid than the other roots, and are very useful for either healthy or sick horses, as also for young colts, by all of which they are much appreciated. They are laxative and slightly diuretic. Carrots should always be cut lengthwise or finely chopped, otherwise they, too, may be a cause of choking.
Steaming or cooking of food is only advisable where fattening is the object to be obtained, or in the case of colts two to four years of age when the gums are tender from the irruption of the molar teeth, or again in the case of old animals with defective teeth.
Dirt and Dust Extraction.
In all stables where the number of horses is considerable, a dust extractor is most desirable and economical, the amount of dust extracted being astonishing.
Horses should as a rule be fed by weight and not by bulk. Oats, for example, will vary as much as 20 per cent to the bushel.
It is a useful rule, if there is a weighing machine available, that working horses should be regularly weighed, say once a month, and the weights noted for reference. In this way an early discovery can be made of a horse losing or gaining weight and its cause sought for, particularly as to overwork, over, under, or improper feeding, or the presence of disease. In any of these cases it is obviously to the advantage of the owner that he should as soon as possible become acquainted with the fact.