188 DISEASES OF THE CHEST. 



the Scotch breed, had every appearance of good health, except that she 

 frequently fell into a fit after having run a little way, and sometimes even 

 after playing .in the yard. She was several times bled during and after 

 these fits. When I examined her, I could plainly perceive considerable 

 and violent spasmodic motion of the heart, and the sounds of the beating 

 of the heart were irregular and convulsive. She was sent to the infirmary, 

 in order to be cured of an attack of mange ; but during her stay in the 

 hospital she had these fits several times : the attack almost always followed 

 after she had been playing with other dogs. She appeared as if struck by 

 lightning, and remained motionless for several minutes, her gums losing 

 their natural appearance and assuming a bluish hue. After the lapse of a 

 few minutes she again arose as if nothing had been the matter. She was 

 bled twice in eight days, and several doses of foxglove were administered 

 to her. The fits appeared to become less frequent ; but, playing one day 

 with another dog, she fell and expired immediately. 



The post-mortem examination was made two hours after death. The 

 cavity of the pericardium contained a red clot of blood, which enveloped 

 the whole of the heart ; it was thicker in the parts that corresponded with 

 the valve of the heart ; and on the left ventricle, and near the base of the 

 left valve of the heart, and on the external part of that viscus, was an 

 irregular rent two inches long. It crossed the wall of the valve of the 

 heart, which was very thin in this place. The size of the heart was very 

 small considering the height and bulk of the dog. The walls of the ven- 

 tricles, and particularly of the left ventricle, were very thick. The cavity 

 of the left ventricle was very small ; there was evidently a concentric 

 hypertrophy of these ventricles ; the left valve of the heart was of great 

 size. 



The immediate cause of the rupture of the valve of the heart had evi- 

 dently been an increase of circulation, brought on by an increase of 

 exercise ; but the remote cause consisted in the remarkable thinness of the 

 walls of the valve of the heart. This case is remarkable in more than one 

 respect; first, because examples of rupture of the valve of the heart are 

 very rare ; and, secondly, because this rupture had its seat in the left valve 

 of the heart, while, usually, in both the human being and the quadruped, 

 it takes place in the right, and this, without doubt, because the walls and 

 the valves of the right side are thinner. 



Diseases of the investing membrane of the lungs, and the pleura of the 

 thoracic cavity, and of the substance of the lungs, are more frequent than 

 those of the heart. 



PLEURISY, 



or inflammation of the membrane of the chest and the lungs of the dog, 

 is not unfrequent. There are few instances of inflammation of the lungs, 

 or pneumonia, that do not ultimately become connected with or terminate 

 in pleurisy. The tenderness of the sides, the curious twitching that is 

 observed, the obstinate sitting up, and the presence of a short, suppressed, 

 painful cough, which the dog bears with strange impatience, are the symp- 

 toms that principally distinguish it from pneumonia. The exploration 

 of the chest by auscultation gives a true picture of it in pleurisy ; and, by 

 placing the dog alternately on his chest, his back, or his side, we can readily 

 ascertain the extent to which effusion exists in the thoracic cavity ; and, if 

 we think proper, we can get rid of the fluid. It is not a dangerous thing 



