286 



PARTICULAR LAMENESSES. 



more propriety to those which take the form of a ring round 



the bone. 



Eing-bone is of two kinds, true and false. The false ring- 

 bone may be dismissed in a few words ; it is an exostosis, 

 situated about the middle of the os suffraginis, due to an in- 

 creased development of one or both of the roughened ridges on 



this bone, which 

 give attachment to 

 the sesamoidean 

 ligaments. When 

 very large, it may 

 cause lameness ; as 

 a rule, however, it 

 never gives incon- 

 venience to the 

 animal, and is not 

 always to be look- 

 ed upon as a cause 

 of unsoundness. It 

 may be compared 

 to a splint thrown 

 out for some bene- 

 ficial purpose. 



The true ring- 

 bone is quite an- 

 other matter, and 

 ^:^=^ is an unsoundness 

 '■_ -^^ in every sense of 

 ^^^ the word, involv- 

 ^^^^ ing important arti- 

 _^?W^ culations, and giv- 

 -ir_ ing rise to obsti- 

 nate, and often in- 

 curable, lameness. 

 There are two 



Fig. 45. — High ring-bone. 



kinds of true ring-bone, the high and the low ; it is called high 

 when it involves the proximal inter-phalangeal articulation or 

 pastern joint ; and low, when it involves the distal inter-phalan- 

 geal articulation or coffin joint. In many instances both forms 

 exist at the same time. Photo-lithograph, Plate III, Pig- 5, is 



a good illustration of tliis. 



