180 



COMMON DISEASES. 



it will generally be found that both hocks are alike. The knees 

 may have similar peculiar development, and yet be perfectly 

 sound. 



Examination. — An examination for soundness should be sys- 

 tematic and thorough, although it may be rapidly done. Examin- 

 ation should be made with a horse in the stall ; as he backs out, 

 stands at rest and in motion. In the stall to see whether the 

 horse cribs or weaves, or has any other stable habit which is ob- 

 jectionable. As the horse backs out of the stall he may show 

 peculiar use of the hind legs or imperfect control, due to serious 

 disorders of the nervous system. \^ery frequently the first intima- 

 tion of spavin may be had as the horse is made to step from side 

 to side, particularly as he steps toward the spavined leg. 



FIG. 66. SPAVINS. TV/O TYPES. (M. H. R.) 



I. Spavin with :\Iarkod Bony Enlargement. A, Metatarsals; B, tarsals 

 with enlarKcmcnt and anciiylosis. 



II. Blind Spavin. Extensive ulceration of articular surfaces; no enlarge- 

 ment; no anchylosis. 2, Os calcis; 3, scaphoid or large cuneiform. 



At rest. — With the horse at rest the observer should begin in 

 front and examine the cars for hearing, for tumors that may de- 

 velop around the Iwse, for split ears, etc. 



The eyes should be examined to test the sight, bearing in mind 

 that moon blindness, which recurs at intervals and leaves the eye 

 more or less nearly normal between times, still shows a weakened 

 or squinting appearance that is suggestive. 



The nasal eliainbers .'^hould l)c examined for ulcers, scars, 

 or (liscliarf,a^s which would suggest possible glanders, bearing in 



