462 DISEASES OF THE CIRCULATORY SYSTEM. 



ditioDs of which we have just spoken is occasioned by the attempt 

 to identify cardiaG palpitations and the diaphragmatic spasm. 



In comparing the abdominal pulsation to a spasm of the dia- 

 phragm we agree with most authors (Apperley and Castley, Beeson, 

 Boiteau, Goubaux, Hering, Cagny). The spasmodic contractions 

 of the diaphragm explain perfectly the intense abdominal shocks. 

 A simple circulatory trouble in the posterior aorta, and still less 

 the aneurism of this bloodvessel, could not produce such serious 

 effects ; the same is the case with the isolated contraction of the 

 abdominal muscles (Delafond), which would make these phenomena 

 similar to expulsive exertions.^ Abdominal pulsations have been 

 attributed to an alteration of the hepatic and splenic arteries 

 (Milanese), but this is a purely imaginary theory. Palpitations 

 have also been confounded with the phenomena produced by 

 thrombosis of the crural arteries and of the posterior aorta. From 

 these considerations we must conclude that abdominal pulsations of 

 the horse form an affection which is similar to hiccough in man 

 (neurosis of the diaphragm). They may appear isolated or may 

 coexist with cardiac palpitations. 



True palpitations have been observed in the dog and the horse 

 (Fricker, Brusasco) ; Fricker has seen these in a pet dog which 

 was cured in thirteen days by the administration of small doses of 

 digitalis. In a similar case Brusasco has used with advantage 

 hydrate of chloral, given in doses of 3 grammes, 



MYOCARDITIS: INFLAMMATION OF THE CARDIAC 



MUSCLE. 



Btiology. Myocarditis, which is very rare and difficult to 

 recognize in our animals, is ordinarily of an infectious nature. It 

 may be produced by aphthous fever (Johne), septicemia, pyemia, 

 tuberculosis (Johne), contagious pneumonia of the horse, etc. ; in 

 certain cases it is due to colds and to excessive exertions. At times 

 it occurs as a secondary affection through propagation to the myo- 

 cardium of an inflammation localized at first upon the endocardium 



1 The existence of this phase of the disease has been irrefutably established by 

 Delafond (see Bull. Soc. centr. Vet., 1851). In two horses used for surgical experi- 

 ments we have observed these abdominal shocks, which seemed to originate in the 

 flank, and, like Delafond, we were able, after a laparotomy, to recognize that they 

 were not produced by the diaphragm, but really by the abdominal muscles, and espe- 

 cially by the ilio-abdominalis. — n. d. t. 



