spavin

patti A disease of horses characterized by a bony swelling developed on the hock as the result of inflammation of the bones.
1920, w:Peter B. Kyne|Peter B. Kyne, The Understanding Heart, Chapter XII

“As an inventor,” Bob Mason suggested, “you're a howling success at shooting craps ! If I were as free of spavins, ringbone, saddle-galls, and splints as you are, I'd have that nanny-goat in here, hog-tie her, flop her and let the boy help himself. (..)”