232 
D. McEACHRAN. 
If we take for illustration of the above remarks, fifty-four dried 
specimens of bone-spavin which I have collected in the museum of this 
College, we will find the following instructive facts: 
Seven specimens in which all the articulations are involved in 
anchylosis except that between the tibia and astragalus. 
One in which all the small bones except the os calcis are involved. 
Twenty-eight in which the cuneiforms are united to one another and 
to the metatarsus. 
Fourteen in which the ossification is confined to the articulations 
between the os calcis and astragalus. 
Three (properly called splint) in which the ossification is merely 
between the internal splint-bone and the cannon. 
One where the exostosis is confined to the antero-internal part of 
the cannon-bone, not involving the splint or cuneiform bones. 
Out of the twenty-eight specimens in which anchylosis of the cunei¬ 
form bones has taken place, we only find seven in which the cuboid is not 
involved in the ossification. True, the ossification is interosseous, and 
would not be perceptible on the outside of the hock, even to an acute 
observer, during life; but that fact does not in any way justify the pop¬ 
ular error that ‘ ‘ bone-spavin is but very rarely formed on the outside of the 
hock." In the same specimens we find also two of antero-internal 
spavin in which the anchylosis is so smooth and bulges so little, that it 
would be impossible to detect any enlargement during life, yet we find 
the anchylosis complete, and involving the metatarsus with the three 
cuneiform and cuboid bones. 
If we take these fifty-four specimens as a fair representation of this 
disease, it will thus be seen that while the inflammation would appear to 
originate and occur most frequently at the antero-internal part of the 
hock, it seldom confines itself to that location, but in three fourths 
of the cases the disease has extended to the outside of the metatarsus as 
well. 
Next in importance from the frequency of the occurrence of in¬ 
flammation leading to ossification, we find the articulations between the 
os calcis and astragalus furnishing fourteen out of fifty-four (more than 
one fourth,) exclusive of cases of complete anchylosis of the hock. 
In examining these specimens we find that, with one or two exceptions, 
there is no external enlargement which could be diagnosed during life 
with any degree of certainty, yet we find from the completeness of the 
anchylosis the inflammatory process must have been active while it 
lasted. That this is a very common seat of hock lameness a long 
