SPAVIN. 
183 
means the same, low spavins, are seen existing for years upon 
horses’ limbs without giving rise to high or genuine spavin and 
lameness. And this it was that led old authors on farriery, 
from Gibson downwards, to make the remark, that high spavins 
were “ dangerous” when compared with low spavins. 
The Pathological Seat of Spavin must be looked for upon 
the cushion* bones, upon the joints they form between each other, 
as well as with the metatarsal bone below, and the astragalus 
above. Too much weight thrown upon these bones and joints, 
shocks of concussion ^coming upon them, excite inflammatory 
action in their articular cavities and outward connexions and 
coverings, and the result is, ulceration of the one, ossification 
and exostosis of the other. So long as lameness is present, without 
tumour or other external sign, it would seem either that the disease 
was confined to the articulating surfaces, or else that osseous 
deposition took place in parts where, externally, it could not be 
detected. It must be remembered, however, that the ordinary 
case of spavin consists in the appearance of exostosis and lameness 
together : at least, from any report or history we in general obtain, 
we are unable to say which of the two has made its appearance 
the first. Therefore it would seem, in the generality of cases of 
spavin, exostosis being a primary symptom, that the inflammation 
originated in the ligamentary and periosteal tissues uniting and 
clothing the cuneiform bones ; and that the inner in preference to 
the outer side of the hock joint became affected from the stretch 
and strain on that part being the greatest, in consequence of the 
inclination of the limb and preponderance of the weight to the 
inner side, rather than, perhaps, to the circumstance of the inde- 
pendent articulation of the inner small metatarsal bone, for we 
know that exostosis is not confined to the spavin-place. In post- 
mortem examinations we find coatings of osseous matter extending 
round upon the front of the cuneiform joints : and such more fre- 
quently, I believe, exist in this situation than we are apt to imagine ; 
since in the living subject it is difficult, often impossible, to detect 
exostosis in this situation, on account of the osseous depo it being 
concealed by the ligaments of the cuneiform bones, as well as by 
the tendon of the flexor metatarsi. Cases, however, do present 
themselves, in which tumour in front is, by close observation, to 
be detected. 
When once Exostosis has formed, there seems hardly i 
limit to its extension. Certainly the higher it grows the worsqjj| 
its effects it becomes; for then, not only are the cuneiform joints 
rendered anchylosed by it, but that with the astragalus as well , 
* I call the two large cuneiform, cushion bones ; resembling as they do, i 
situ, cushions placed one upon the other. 
