- a disease of the hock joint of horses in which enlargement occurs because of collected fluids (bog spavin ), bony growth (bone spavin ), or distention of the veins (blood spavin ).
- an excrescence or enlargement so formed.
- enlargement of the hock of a horse by a bony growth (bony spavin) or fluid accumulation in the joint (bog spavin), usually caused by inflammation or injury, and often resulting in lameness
