482 Veterinary Medicine. 



Perforation of the heart from ulceration is sometimes seen 

 in cows when sharp-pointed metalUc 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 parasites in its substance, 

 render the heart more friable and predispose it to rupture. 



Lesion. The rupture during systole is often at the fibrous 

 ring encircling the aorta or pulmonary artery ; in other cases 

 from concussion in the muscular wall of ventricle or auricle. 

 The following seats have been noted : auricles, fibrous rings at 

 the base of the auricle, or encircling the aorta or pulmonary 

 artery, through the body or near the apex of the left ventricle, 

 at the azygos. The laceration in the muscular wall is usually 

 in a line with the fibres, and from a third to an inch in length. 

 The outer edges of the wound are much more irregular than the 

 inner. The pericardium is filled with blood, and the muscular 

 fibres on each side of the opening are torn and shreddy and filled 

 with blood clots. The blood has been known to escape into the 

 pleural cavity and in case of a foreign body coming from the 

 reticulum, it may pass through the fistula into the stomach. 



Symptoms. Death may be practically instantaneous. If de- 

 layed there is hurried breathing, anxiety, weakness, pallor of 

 the mucous membranes, staggering, trembling, vertigo, stupor, 

 and convulsions. 



In dogs rnpture of the heart has been noted in connection with 

 operation for ascites (Stockfleth, Benz), with purpura hsemor- 

 rhagica (Mathis), with a fall of 20 feet (Rodet), with arrow- 

 wound and other traumas (Nocard), also with ulcerous endo- 

 carditis (Mathis.) 



In a pis: Rosario saw a single case in a pale heart and anaemic 

 animal. 



In chickens Larcher records two cases, and Cadeac two more 

 associated with diphtheria. 



