LAMENESS, FROM VARIOUS CAUSES. 339 



owing to the spread of ossification; that is, the coffin bone and 

 pastern bone become united together by bony growth. Ring- 

 bones are the result of hereditary predisposition, structural organi- 

 zation, and accident. As to hereditary predisposition, there is no 

 doubt but that some sires, the subjects of spavin, ring-bone, and 

 other forms of exostosis, father foals which often, sooner or later, 

 tnemselves become victims of the same disease. The same law 

 applies to dams. Breeders of horses are fully aware of this fact, 

 and are, therefore, more careful than formerly in the selection of 

 parents for the purposes of breeding from. As to form, many 

 living cases which now exist prove the truth of the statement that 

 low-bred, coarse-limbed horses, with short, upright pasterns, are 

 frequently subjects of ring-bone. Why such should be the case 

 with animals with upright pasterns is easily explained, as follows : 

 The pastern bones in a well-formed limb ought to form an oblique 

 angle with the cannon-bone (metacarpus) placed above them; 

 whereas, if the pastern is upright, the column of bones from the 

 elbow-joint to the foot is, necessarily, placed in one and the same 

 straight line, causing, at every step made by the animal during 

 progression, a severe concussive shock to be produced on the whole 

 column of bones, but more especially on the pastern bones, owing 

 to the superincumbent weight of the bones above them. Thus one 

 or more of the pastern-bones become injured and inflamed, and, 

 finally, as a consequence, exostosis ensues, the coronet becomes in- 

 volved, and the disease denominated ring-bone is set up." 



Mr. Percivall quotes from Gibson : " When a well-formed, 

 high-bred horse happens to have a ring-bone, we may conclude it 

 to proceed from some accident rather than from any natural fault. 

 The disease may also be produced by a blow to the part, and from 

 the efforts made to increase speed, when concussion causes injury, 

 inflammation, and consequent exostosis to the bones of the pastern. 

 As to treatment, we should recommend the proprietors of young 

 horses, subject to ring-bones, to place their horses in a state of 

 nature, by removing the shoes from their feet, and by turning out 

 to grass. If this, after a fair trial, fail, then the treatment for 

 spavin and other exostosis must be resorted to, such as blistering 

 the affected part and keeping the animal on a low diet. No dis- 

 ease is more troublesome to treat, or more demands the strict at- 

 ention of a skillful veterinarian." 



Causes.- — The exciting causes of ring-bone are ligamentarj 



