ATROPHY OF THE HEAET. 571 



From the records of veterinary medicine, both in this 

 country and abroad, many wonderful instances of dilatation of 

 the heart may be gathered. Both Mr. Percival in his ' Hippo - 

 pathology,' and Mr. Gamgee in his ' Domestic Animals in 

 Health and Disease,' drawing from these records, relate some 

 very significant and well-marked cases. Some of the cases 

 mentioned by the latter I had the opportunity of examining, 

 and can vouch for the reality and accuracy of what is there 

 stated. 



II. Atrophy of the Heart. 



Unnatural lessening or loss of the substance of the heart, 

 as well as increase and augmentation, is observed in the 

 horse and other of our patients. This abnormal decrease 

 may, as with the hypertrophic state, be particular or general ; 

 it may involve only portions, or affect the whole. It may 

 occur without alteration of the cavity or cavities ; or it 

 may, as with the opposite state, be attended with thinning of 

 the walls and dilatation of the cavity — the former known as 

 simple, the latter as eccentric atrophy. The frequency with 

 which the several cavities of the heart are usually affected 

 with atrophy has by some observers been stated to be the 

 opposite of that which holds good in the condition of hyper- 

 trophy, the auricle being more liable to atrophy, the ventricles 

 to hypertrophy. 



The anatomical characters are lessening of bulk and abso- 

 lute weight, with often undue pallor of the muscular tissue, 

 which is occasionally suffering from degenerative changes. 



The symptoms, general or local, are not diagnostic. There 

 is much weakness, with feeble cardiac impulse distributed over 

 a restricted area. 



III. Fatty Changes in the Heart. 



Of the diseased conditions affecting the intimate structure 

 of the heart dependent on fatty changes, we have in the horse, 

 as other animals, two forms— (a) Fatty infiltration, or deposi- 

 tion upon and amongst the muscular fibres of oil or fat in the 

 form of ordinary fat-cells or adipose tissue ; (6) Fatty degene- 

 ration, or metamorpJiosis, in which fat or oil particles take the 

 place of the true muscular elements in the minute tubular 



