RING-BONE. 
609 
surfaces. Such adhesions are often accompanied by excessive volar 
flexion. By lifting the foot the anchylosis of the joint is discovered 
immediately an attempt is made to rotate, to flex, or to extend it. From 
the above it will be clear that the degree of lameness in no way depends 
on the size of the exostosis; a large exostosis may only produce 
slight lameness, and vice versa. 
The diagnosis of ring-bone is very difficult unless the enlargement 
is well developed. In foals the phalangeal epiphyses appear well 
developed, and the coronet-joint lies high in consequence of incomplete 
development of the hoof. The proper distribution of weight on all four 
feet and the absence of lameness show this condition to be normal. 
Thickening of the skin may be recognised by palpation, and ossifica¬ 
tion of the lateral cartilage can easily be distinguished from ring-bone if 
palpation is practised with any approach to care. 
It is more difficult to distinguish ring-bone from strain of the 
coronary-joint, though the latter is accompanied by acute inflammatory 
symptoms (increased warmth and pain on pressure), which sufficiently 
distinguish it. As, however, chronic disease consequent on strain also 
falls under the designation ring-bone, conditions occur which may be 
described by either term. The disease may be masked by thickening 
of the skin around the joint, a condition induced for purposes of 
deception; the trick succeeding the more readily as laymen are pre¬ 
disposed to refer lameness to the skin injury. It is always safer to take 
the opposite view. 
Course and prognosis, As a rule, the disease is chronic, though 
the different forms of ring-bone exhibit many peculiarities. The 
articular form generally sets in slowly, though at times it results from 
acute synovitis, and is then difficult to differentiate from synovitis itself. 
As complete recovery cannot be expected, the prognosis depends on the 
degree of lameness and the work required of the horse. Lameness of 
sufficient severity to prevent work can only be removed by neurectomy. 
Exostoses, involving the front of the joint, offer little chance of cure, and 
those fixing the joint none at all. 
Periarticular ring-bone sometimes results from acute periarthritis of 
the coronet-joint, or from repeated strain of its ligaments. Improve¬ 
ment or cure depends on the nature of the pathological processes, and 
the possibility of removing the active cause. When the joint is much 
enlarged and the position of the pastern altered, recovery is not to be 
expected. The more nearly, the enlargement approaches the joint, 
especially the front or back of the joint, and the nearer it is to the 
hoof, the more serious the condition; high ring-bones are therefore less 
dangerous than those in the coronet region. The prognosis is also less 
hopeful where conformation is bad. When, on the other hand, errors in 
V.S. R 11 
