\Spav"in\, n. [OE. spaveyne, OF. esparvain, F.
['e]parvin; akin to OF. espervier a sparrow hawk, F.
['e]pervier, fr. OHG. sparw[=a]ri (G. sperber), fr. OHG.
sparo sparrow, because this disease makes the horse raise the
infirm leg in the manner of a sparrow hawk or sparrow. See
{Sparrow}.] (Far.)
A disease of horses characterized by a bony swelling
developed on the hock as the result of inflammation of the
bones; also, the swelling itself. The resulting lameness is
due to the inflammation, and not the bony tumor as popularly
supposed. --Harbaugh.

{Bog spavin}, a soft swelling produced by distention of the
   capsular ligament of the hock; -- called also {blood
   spavin}.

{Bone spavin}, spavin attended with exostosis; ordinary
   spavin.