My horse is 3, TB and grew quickly. She has clicking in her joints. She clicks every time she steps in both her back fetlocks. Can you suggest a good supplement for her joints? Is EquinylCM a good one? Any others that you can think of that might be helpful or HARMFUL to a young horse, I don't want to do any damage either! AV, Connecticut

Dear AV:
"Clicking of the joints" is one of the more common questions we get and is a frequent cause for horses to visit our clinic. In most cases it is related to immaturity, lack of conditioning and sometimes size. It is also (rarely) associated with OCD, but not usually. The mechanism of the sounds is the subject of a lot of speculation and some research. Think of the people you know who can crack their knuckles! It's the same thing. If you cause a closed hydraulic system to suddenly expand by stretching the membrane, there isn't enough fluid to fill the space, so oxygen will actually form bubbles and come out of solution and form an air interface with the joint. This is the sound you hear in most cases. It is harmless. One of the other sounds you hear is the cartilages slipping over each other and then falling back into place.

So what to do? Usually, after we've ascertained that there is no cartilage damage, lameness or inflammation, we recommend lots of turn out, conditioning and steady regular work. Any lameness should be explored, but the sounds themselves almost never correlate with injury. Most horses grow out of it, but many continue to click their entire lives.

Jay Merriam DVM
Massachusetts Equine Clinic