TYPES AND MARKET CLASSES OF LIVE STOCK 481 



Certain unsoundnesses are ordinarily referred to as "heredi- 

 tary," on account of their marked tendency to reappear in suc- 

 ceeding generations. More correctly, however, it is some weak- 

 ness of conformation that is transmitted which predisposes the 

 members of the family to one or more unsoundnesses. Con- 

 siderable difference of opinion exists among well-informed per- 

 sons as to the hereditary transmission of some unsoundnesses. 



A number of minor troubles which are not unsoundnesses 

 are here given brief mention, because of the frequency with 

 which they are met and to satisfy curiosity regarding them. 

 Treatment is briefly mentioned in some cases for a similar reason. 

 Many minor troubles are important because they blemish a 

 horse. A blemish merely detracts from the appearance of an 

 animal, whereas an unsoundness interferes with his working 

 capacity. Many unsoundnesses are blemishes as well. A 

 study of the ills to which the horse is heir shows that his eyes, 

 legs, and wind are the seats of unsoundness. 



Blindness. Any defect of sight is a serious defect in a 

 horse, and eye trouble always furnishes grounds for rejecting 

 horses for unsoundness. Inspecting a horse for blindness re- 

 quires expert knowledge of the diseases of the eye, and, although 

 the average horseman can in many cases discover defective 

 eyes, no horse is safely passed as sound in eyes except by a well- 

 qualified veterinarian. Severe weeping, partially closed eye- 

 lids, sunken eyes, inability to bear strong light, a cloudy ap- 

 pearance of the cornea, unnatural or dull color, failure of the 

 iris to contract to a considerable degree when brought from 

 darkness to light, too active play of the ears, failure to blink 

 when an object is passed close to the eye these and many 

 other conditions give evidence of defective vision. (See also 

 cataract and periodic ophthalmia.) 



Blood spavin. Blood spavin is situated in front and to 

 the inside of the hock, and is merely a varicose or dilated con- 

 dition of the vein passing over that region. It occurs directly 

 over the point where the bog spavin is found, and is some- 

 times confused with the latter. It constitutes a blemish rather 

 than an unsoundness. 



Bog spavin. This is a round, smooth, well-defined swell- 

 ing in front and a little inward of the hock. On pressure it 

 disappears to reappear on the outside and just behind the hock. 

 It is caused by a weakness in the synovial sacs of the joint, 

 accompanied by a hyper-secretion of synovial fluid or joint oil. 



