Originally Posted by Ashleysmardigrasgirl
a windgall is quite possible but not likely... Its most commonly refered to as a type of inflmation of synovial membrane which surrounds the fetlock and digital flexor tendon sheath. Tenosynovitis is the fancy term used to describe the inflamation of synovial membrane (referred to as synovitis) linning of the tendon sheath. This whole thing makes up what windgalls typically are but bear in mind this is all in the fetlock not the hock...
Your horse in my opinion obviously; looks like he/she has got bog spavin. Bog spavin is commonly the name used to describe synovitis of the hock or tarsal joint. This occurs when the sbasically the same process described int he fetlock occurs int he hock simply put your horse experience a trauma (over worked, tweaked itself, bucked landed funny, etc) and the membrane sac which surrounds his joints in his hock became inflamed to protect themselves just as your elbo or knee might swell if you fell relaly hard on it. However in horses repeated injury to the area is usually what causes the inflamation.
I would look critically at your horses conformation and possibly reconsider your training regieme as it may be a little too heavy for his ability. However if that doesnt work or is clearly not the case then you may be dealing with a fracture or improper farrier work.
If rest doesn';t fix it I would schedule a raidograph or at the very least call a vet out.
Are these bumps on the interior portion of his hock as well or just the antierior?
Ah yes my bad! I wasn't sure if a wind gall could appear at the hock as well as the fetlock :P Thanks for clearing that up!