310 



PARTICULAE LAMENESSES. 



liorse does not always cause lameness, we are warranted in 

 endorsing the popular and common conclusion, that an old- 

 standing spavin seldom does harm, and that it 

 is only during its formation it interferes with 

 tlie usefulness of the animal. 



But a spavin, to terminate so favourably, must 



be limited in its extent ; perfect immunity 



from a recurrrence of lameness may result 



when it is confined to the cuneiforms and 



metatarsals ; but if the superior surface 



of the cuneiform magnum and the lower 



articulating surface of the astragalus are 



involved, in addition to the others, I do 



not think that perfect restoration can be effected. 



In many of the specimens in the College Museum, 



not only are all the gliding bones involved, but 



also the bones of the true hock-joint. Such 



clianges must cause permanent lameness. 



In conclusion, I may mention that a practice 

 prevails in some parts of the country by which 

 liocks that present a want of symmetry in the 

 seat of spavin, and particularly if one hock is 

 larger than its fellow, are made as nearly alike 

 as possible. The operation is called causticking, 

 and is as follows : — Upon the coarse hock an 

 incisioQ is made a short distance below the 

 spavin, and a piece of caustic inserted sub- 

 cutaneously to the hcLse of the enlargement. 

 This causes inflammation and a filling up of 

 tlie hollow beneath the spavin ; in fact, it hides 



the latter by elevating the former. 

 Fig 53a 



Occult bone-spavin. OccuLT Spavin, as shown in Fig. 53a, is a form 

 of hock disease in which inflammation of the 

 cuneiform bones and interosseous ligaments, with anchylosis, is 

 unaccompanied by any apparent external formation of bone ; the 

 spaces between the bones may be filled up with ossific matter 

 as in the illustration, but there is no visible enlargement. 



