Williams, Fisher, and Udall: The. Spavin Group. 43 
As a group one of the important characteristics is the ab- ~ 
sence of traumatism. Admittedly traumatism at times occtirs 
and modifies the localization and intensity of the visible disease 
process, but these cases are so: exceptional and stand out so 
boldly as to rather emphasize the rule. 
Another important factor in differentiation is the well- -nigh 
constant multiplicity of lesions. They are largely symmetrical, i 
if one hock has a spavin, so has the other, if there is one ring- 
bone there are probably others, if navicular disease exists in one 
fore foot it is well-nigh sure to co-exist in the other. Ifa spavin 
is present, a search will probably reveal slight ringbones, if 
gonitis appear, there can probably be found a spavin or ringbone. 
Most practitioners do not search for these and many fail to 
recognize their diagnostic value, which is their sole importance. 
as a rule, because the smaller of these exostoses are not un- 
sightly and have little danger for the usefulness of the patient. 
The character of the lameness is quite unlike traumatisrn 
whether infected or aseptic. In the former of these two there 
is a tendency to suppuration or erysipelatous inflammation, in 
the latter, like strains, etc., there is sudden lameness quickly 
reaching a crisis and gradually receding. In this group the 
lameness is insidious and persistent, with the few exceptions 
we have noted. 
The local manifestations possess a high value, the exostoses 
are characteristic and we rarely meet with bony enlargements 
likely to be mistaken for these. It is true that the exostoses may 
be of so small size that different examiners will hold different 
opinions and admittedly they exist in imperceptible gradations 
and finally reach a point where their presence or absence cannot 
be decided during the life of the patient. 
We have already referred to the subject of urinalysis under 
the heads of pathology and symptoms. 
The differentiation between the lamenesses arising from the 
various members of the group is frequently difficult and not 
rarely impossible. It is not always essential that the differentia- 
tion should be clear, yet is nearly always advantageous. 
If a horse, lame in a hind leg, presents an evident spavin 
and at the same time shows gonitis with the rigid stifle and 
distension of the femoro-patellar capsule, we may rest assured 
in the present state of our knowledge, that he is lame in the 
stifle, but may not be able to exclude the hock. We might find | 
