28 SOUNDNESS IN HORSES. 



only reasonable to expect tliat the synovial sheathes will 

 have secreted a large supply of lubricating fluid ; and that, 

 if the OS calcis is short, any fulness of the sheath of the 

 perforans tendon will become all the more apparent. A 

 large bog-spavin may give rise to the appearance of 

 thoroughpin, by the fact of its pushing the synovial 

 bursa of the tendon up out of its place. In this case, 

 the bog-spavin, and not the thoroughpin, should be 

 judged as to the probable effect on the animal's useful- 

 ness. Young horses, from weakness of the joints, often 

 show bog-spavins and thoroughpins which may go 

 away in time. The existence of such ailments, in their 

 case, should, I think, be regarded with suspicion ; for 

 joints thus affected cannot be considered to be capable 

 of a reasonable amount of immediate work. If, however, 

 the animal is too young for saddle or harness, his defects 

 should, naturally, be estimated on the same footing as if 

 he had been broken in. We may take the foregoing 

 remarks on thoroughpin in conjunction with those 

 made on bog-spavin (see page 13) ; as both affections 

 are of the same nature, and are closely connected with 

 each other. 



Thrush. — In Barrett v. Preece* (Shrewsbury County 

 Court), it was decided that the fact of a horse which was 

 warranted sound, having thrush, was a breach of the 

 warranty. 



* Veterinarian for 1858, p. 235. 



