Stiffness, swollen joints, obvious pain, loud popping sounds from hips and knees...
There are lots of things can indicate it. If you notice particular soreness after she stands on a hard surface for a long time, or after turning in circles, or after strenuous work there's a chance.
But I am not a vet, and I think if you suspect it, you need to have the vet check her, get her some shots and supplements.
It is manageable, with proper care.
ETA: My mare rides beautifully, but she -needs- her Legend shot every few months, and she -needs- her MSM. Otherwise she gets stiff and incredibly sore. I am also considering getting her a set of SMBs to absorb more shock and prevent further damage and pain.
ETA again: My mare has 24 hour turn-out, but has access to her stall if she chooses, instead of being stalled at night. It has helped immensely.
Last edited by LeahKathleen; 04-30-2009 at 02:15 AM.