3i8 Veterinary Medicine. 



Stephenson probably weighed the heart while filled with blood. 

 A diseased heart weighed in this way by Thomson amounted to 

 34 Bbs., one by Gerlach, 19 lbs., an ox's heart by Herrau 36 flbs. 

 In Stephenson's case there was further an extraordinary dilatation 

 of the anterior venacara. Haycock (Veterinarian, 1850), records 

 a case in which though the heart only weighed 10 flbs. 8oz., yet 

 the walls of the ventricles were double the normal thickness, those 

 of the left being 2^ inches while those of the right were i inch. 

 An estimate from the thickness of the walls, it must be borne in 

 mind, is not so satisfactory as the absolute weight taken after the 

 removal of the large vessels, the superfluous fat and the contained 

 blood. 



The usual coincidence of other complaints supports the state- 

 ment that it is mostly due to obstruction to the circulation. A 

 few cases will illustrate. Dyer reports the case of a hunter in 

 which with general hypertrophy and dilatation of the right auri- 

 cle, the pulmonary artery was so large as to admit the fist. (Vet- 

 erinarian, 1861). Halloway relates a case in which there were ex- 

 tensive internal deposits of melanotic material, especially in the 

 mesenteric glands, liver, spleen, and kidneys (Veterinarian, 1850). 

 Haycock records a case with thickening of the auriculo- ventricu- 

 lar valves on the right side, and of several of their tendinous 

 cords, also a diseased liver which had ruptured before death (Vet- 

 enarian, 1850). Perci vail publishes a case associated with pleu- 

 risy and rheumatism (Veterinarian, 1858). Henderson furnishes 

 a case associated with diseased right auriculo-ventricular valves 

 and enlarged liver weighing 55 lbs. (Veterinarian, 1847.) 



Symptoms. In simple hypertrophy the heart beats are more 

 forcible and prolonged so that the period of silence or rest is 

 shortened. This is due to the greater length of time taken up in 

 the contraction of the ventricles. For the same reason the pulse 

 which mayor may not be accelerated, irregular or intermittent, is 

 full and rolling or as it were prolonged. The first sound of the 

 heart is prolonged and low or muffled, sometimes almost inaudible 

 while the second is unnaturally loud. Sometimes when one ven- 

 tricle only is enlarged that may complete its contraction later than 

 the other and the second sound is repeated as in the syllables 

 lub — tip tip. A duplication of the first sound only is less com- 

 mon. If the sounds are heard over a greater extent of the chest's 



