Navicular syndrome is a common cause of lameness in the horse. This problem may account for 1/3 of all chronic lameness. Unfortunately, navicular syndrome remains only loosely defined.

I've recently been called to trim a horse and noticed that the hoof on the off-side front has separated from the coronet front by about 3 inches. After pointing out this problem to the owners, they told me that the horse was totally lame about a week prior and it's now sound and putting full weight on the foot. There's no sign of infection, and during trimming the horse shows no signs of discomfort. There's a lot of movement in the separation opening and you can see a sensitive area that appears to be healthy.

Is it really navicular disease, or just tendonitis? Are they the same thing? If they are different, how can they be treated differently?

What impact does urine in a stall have on hoof quality, and how do you treat urine-damaged hooves?