Part 50

Horses affected in this way are useless. Cattle may sometimes be partially fattened by preserving them from all sources of excitement, by keeping the bowels regular and by combating any paroxysms with sedatives, such as aconite, veratrum, hydrocyanic acid, or opium, and with digitalis.

FATTY DEGENERATION OF THE HEART.

Causes, improvement in the direction of easy fattening, inactive life, best breeds of butcher cattle and pigs suffer. Symptoms, weak, irregular, intermittent pulse, palpitation, unfitness for exertion, general heart symptoms.

In addition to the fibrous and bony transformations to which the substance of the heart’s walls is subject, a fatty metamorphosis is frequently met with. In most cases the fat accumulates in great masses externally, but in others the muscular tissue has to a greater or less extent lost its natural structure and fatty granules have taken the place of the sarcous elements. In overfed oxen the right cavities of the heart rarely escape dilatation, and this condition is very often accompanied by the fatty change. Virchow has shown that highbred English pigs imported into Germany are subject to a similar affection of the heart and of the entire muscular system. It may occur during wasting diseases and from phosphorous poisoning.

The symptoms are weak, irregular and intermitting pulse, palpitation on excitement, weakness of the heart’s impulse in the intervals, incapacity for exertion, sighing, Cheyne-Stokes respiration, loss of control over the limbs when hurriedly driven and tendency to dropsy. It is often associated with dilatation, is rarely distinguishable from it in life, and is equally beyond remedial measures. The feeding animals most commonly affected can usually be fattened if removed from all sources of excitement. In case of phosphorous poisoning improvement takes place when the poison is stopped.

NEW FORMATIONS IN THE HEART. TUMORS. PARASITES.

Glanders, abscess, melanosis, tubercle, polypus, nœvus, parasites—echinococcus, cysticercus tenuicollis, cysticercus cellulosa, trichina, sarcocyst, filaria immitis, strongylus subulatus, strongylus vasorum.

1st. =Deposits of Glanders.= In many cases of glanders and farcy in horses the specific product is deposited in the heart as well as in other internal organs. Such deposits are small but numerous, infiltrating the muscular tissue; their cut surface is dry, finely granular and of a yellowish white color.

2d. =Abscesses= are sometimes formed in the heart from the colonization of microbes from suppurating surfaces.

3d. =Cancer of the heart= has been noticed chiefly in dogs by Leblanc. It occurs only consecutively to cancer in other parts of the body, yet it has sometimes acquired considerable dimensions and interfered materially with the movements of the heart.

4th. =Melanosis= of the heart has been repeatedly noticed in the horse. Some if not all such cases should be classed with cancers, as these internal deposits of black coloring matter in solipedes, have, in our experience, mostly possessed malignant characters, though they are usually simple tumors as developed in the skin of the horse. These black masses usually project beneath the pericardium or endocardium.

5th. =Tuberculous deposits= have been met with in the substance of the heart in cases in which the lungs or other organ were the seat of this disease.

6th. The fibrous growths or polypi due to the deposition and organization of fibrinous material from the blood have been referred to under endocarditis.

7th. Gamgee reports the existence of a vascular tumour of the right ventricle of a horse in the museum of the Turin Veterinary School. It consisted of varicose veins ramifying beneath the endocardium which in its turn was healthy.

8th. The =parasites found in the heart= are various, a. One, the =Echinococcus Veterinorum=, has been repeatedly found in the substance of the heart or projecting from its inner or outer surface. b. Another, the =cysticercus tenuicollis=, has been met with in the pericardial sac of a calf (Reed). c. A third, the =cysticercus cellulosa= infests the muscular structure of the heart of measly pigs. d. The heart like other voluntary muscles of hogs occasionally contains =trichina spiralis=. e. =Rainey’s cysts= (=sarcocysts=) are microscopic ovoid bodies usually found in the hearts of oxen and other animals. f. A round worm, =filaria immitis=, first described as filaria papillosa hæmatica by Delafond and Gruby, lives in the blood of the dog, is one millimeter thick by fifteen to 30 centimeters long. It may obstruct the pulmonary artery (Serres) or the mitral orifice (Silvestre). It may cause various nervous disorders and even sudden death. Its mode of entrance is unknown. g. =Strongylus Subulatus=, 1 to 2 mm. long by 70 to 90 μ. in thickness was found in numbers in a nodule of a dog’s lung, and the dorsal vein of the penis of a dog (Leisering). h. =Strongylus Vasorum= in the right auricle and ventricle of a dog, in pea-like blood clots. It is 14 to 21 mm. long by 1 m. in thickness (Serres).

RUPTURE OF THE HEART.

In the lower animals ruptures of the heart have been observed as the result of (a) extraordinary exertion, (b) violent concussion, and (c) ulceration and degeneration. The rupture of the fatty heart in the lower animals is not common.

=Rupture during severe exertion= occurs in the perfectly healthy heart. The ruptures take place in the weakest point, and most commonly in the fibrous ring which encircles the base of the heart and attaches the great aorta. This is occasionally seen to happen in very spirited horses during a severely contested race or when a heavy load is being dragged up hill. Percivall mentions the case of a horse at a Woolich racing meeting, which had just lost a heat by half a head and which died just after passing the winning post, with ruptured right auricle.

Cases occur during coitus (Hering), tympany (Anacker, Mayer, Perdan) and operations (Stockfleth).

=Rupture from Concussion= more frequently implicates the muscular walls which have not the same power of resistance when they receive the blow in a relaxed condition. Parker met with a case of rupture of the right auricle at its base or at the line of its union with the ventricle. The subject was a pony which ran away down hill and struck his right shoulder violently against a cart wheel. In other instances the rupture takes place in the posterior vena cava, and particularly if its walls have been the seat of disease. Gamgee found rupture of the commencement of the azygos vein in oxen killed by pithing in the slaughter houses of Ferrara, and Professor Maffei subsequently found that out of 3095 oxen killed in these abattoirs 57 had this vein ruptured. Gamgee’s explanation of the occurrence is that “the instant the animals are pithed the walls and contents of the chest become paralyzed, the heart becomes an inert bag filled with fluid, the jerk of which as the animal falls, causes rupture of the containing vessel at its weakest part and this is in truth the vena azygos whose walls are thin and only protected externally by the pleura.” Hertwig gives other cases resulting from falls.

=Perforation of the heart from ulceration= is sometimes seen in cows when sharp pointed metallic bodies from the stomach make their way into its substance. An alleged case of rupture following ulceration of the walls of the right ventricle is recorded by Gaullet.

Inflammation, softening, fatty and calcareous degeneration, dilatation, atheroma, and the presence of parasitis in its substance render the heart more friable and predispose to rupture.

Lesion. The rupture is often at the fibrous ring encircling the aorta or pulmonary artery; in other cases in the muscular wall of ventricle or auricle.

Symptoms. Death may be practically instantaneous. If delayed there is hurried breathing, anxiety, weakness, pallor of the mucous membranes, staggering, trembling, vertigo, stupor, and convulsions.

DISEASES OF ARTERIES.

The chief morbid conditions seen in arteries are: Wounds, inflammation, thrombosis, embolism, degeneration, and aneurisms. Wounds belong essentially to surgery.

ARTERITIS. EMBOLISM.

Internal and external arteritis. Thrombosis, from inflammation. Embolism. Bruising. Stretching. Ligature. Lesions. Extension of clot, color, consistency, adhesion, lamination. Composition of clot. Condition of vessel. Changes in muscles. Causes: muscular tension, embolism. Heart clots, venous clots. Infecting debris. Symptoms: paresis or paralysis on exertion. Local suffering, tenderness, firm swollen artery, derangement of nutrition and function, atrophy. Chronic arteritis: Atheroma. Changes in serosa. Fibrous thickening, atrophy, dilatation. Strongylus. Treatment: rest, anodynes, alkalies, massage.