DISEASES OF THE DIAPHRAGM Spasm of the Diaphragm; Abdominal Pulsation This condition may be met with in any of the domesticated animals, but it is seen most fre quently in the horse and in the dog.
Etiology. The cause of spasm of the dia phragm is not clearly understood. In the majority of instances it is thought to be due to reflex action, the result of indigestion or other affection of the gastro-intestinal tract. It may thus be brought about by defective quality of food, such as mouldy hay or corn, and attacks have been brought on by drinking cold water and by greedy feeding. Irritant poisons may also set up spasm of the diaphragm. Spasm of the diaphragm may also be brought about by over-exertion such as may occur in the hunting field after a fast run, particularly in the early part of the season. Hutyra and Marek record a case in the dog in which the spasms of the diaphragm were due to catarrh of the stomach and bowels. The writer has seen it in a dog occurring at frequent intervals, particularly if any excitement was permitted immediately after feeding. Post-mortem examination in this case revealed that the dog was affected with stenosis of the pylorus followed by dilata tion and hypertrophy, and it is reasonable to assume that lesion to have been responsible for the symptoms. Another asserted cause which is worthy of consideration is intermittent pressure or stimulation of the diaphragmatic nerve as it passes through the mediastinum. This can be brought about by enlarged glands in this area and also spasmodic conditions of the heart. In the latter case the abdominal pulsations would occur immediately after the heart-beats, instead of coinciding more or less with the normal frequency of respiratory move ments, as is the case when due to other causes.
Symptoms. These often appear to be very urgent, and may come on very suddenly; they may pass away equally suddenly. The most noticeable feature is a violent throbbing of the whole body generally corresponding with each respiration, although occasionally, as already stated, they may coincide with the heart-beats. Peculiar throbbing action of the abdominal muscles is also noticed, and this can be appre ciated most easily by laying the hand flat along the asternal cartilages of the ribs. At the same time there may be observed some apparent bulging of the abdominal muscles in this region, owing to narrowing of the posterior margin of the thoracic wall due to the contraction of the diaphragm. There may also be heard a soft laryngeal sound likened to a sob or hiccough at each respiration. The patient appears some what distressed, and in the case of excitable horses profuse perspiration may be set up. During the attack the appetite is in abeyance, and the pulse is generally small and frequent, occasionally palpitating. There is rarely any alteration of temperature. In the majority of cases there are indications of indigestion and irregular condition of the bowels, together with periodical vomiting in animals capable of emesis. The symptoms may pass off in a few minutes, and recur several times in the course of the day; this is frequently the case in dogs. In horses the symptoms are usually more or less continu ous for from several hours to several days, and then may suddenly disappear.
Spasm of the diaphragm is rarely serious in effect, and it is doubtful if any case actually proves fatal as the result of this spasm. In cases where death has been recorded, it is more than probable that the fatal result was due to the original cause responsible for the spasm of the diaphragm.
Treatment. No drastic measures are called for. The spasms during an attack may be cut short by inhalation of amyl nitrite or of chloro form. If that fails hypodermic injection of morphia gr. v. vi. in the horse or gr. 1-i. in the dog will cut short the attacks. In the case of animals that are subject to frequent attacks a course of bromide of potassium should be given. During
the attacks the patient should be kept quiet and free from excitement. Attention should also be paid to the condition of the alimentary tract, a laxative should be administered such as sulphate of magnesia, and an easily digested diet provided. In addition, in susceptible subjects a period of rest and quietness should be enforced regularly after feeding.
Rupture of the Diaphragm; Hernia of the Diaphragm This condition in the majority of cases is brought about as the result of a fall or other violence. Occasionally it occurs in the course of colic in horses, and it has also occurred where the horses have been cast for operation, and in that case probably due to violent straining. In dogs it may be due to having been run over.
Anatomical Changes. The rupture may occur in any part of the diaphragm, but is most commonly met with in the tendinous portion. If the rupture is recent the irregular edges will be more or less blood-stained and congested, with phenomena of inflammation, while in old-stand ing cases of small ruptures adhesions with the viscera may be produced. Some of the abdo minal viscera will usually be found in the thorax, depending on the extent of the rupture. The herniated organs may be portions of the liver, stomach, or intestines. When a small rupture has occurred permitting a loop of bowel to pass through, strangulation is likely to occur with intense congestion and discoloration. In other cases hernia may have occurred through the natural openings of the diaphragm, especially through the oesophageal foramen. In this way loops of bowel of varying length have been found in horses and in cattle; while the writer has observed hernia of half of the liver and gall bladder in a cat, and of the entire stomach in a dog.
It is important to distinguish ante-mortem rupture from post - mortem rupture of the diaphragm, which not infrequently occurs as the result of gas formation in the rumen of cattle and sheep and of the large intestines of the horse after death. In these cases the rupture is usually very extensive and there is a complete absence of vascular disturbance along the borders of the rupture.
Symptoms. The symptoms are variable and depend upon the extent of the rupture. If the rupture is small in extent there may be very little to be observed for some time, since the rent may be occluded by some of the abdominal viscera. If, however, a viscus passes through, intermittent attacks of colic will be brought on, and it may ultimately lead to strangulation and death. dyspnea is not very marked in small ruptures, but it may be shown in animals going downhill. In slightly larger ruptures of the diaphragm respiratory distress may be observed. The patient stands with his hind limbs partially flexed, and horses occasionally sit on their haunches; they rarely lie down. There may be profuse sweating and a short asthmatical husky cough. In very extensive ruptures intense dyspnoea occurs immediately, and death follows more or less rapidly. In cases where a bowel is passed into the thorax auscultation reveals peristaltic sounds in the chest, while tympanitic sounds may be produced on per cussion. In the dog with hernia of the stomach into the chest the most pronounced symptom was persistent vomiting, which could not be allayed by any means, the dog consequently wasted rapidly through inability to retain food. In the cat with the herniated portion of the liver the predominant symptom was wasting, with slight abdominal pain, occasional vomiting, and a yellowish tinge of mucous membranes.
No serviceable treatment is available in rupture of the diaphragm.