He is a 3 and a half year old rescue greyhound, we've had him for 2 years, he has never raced.
I have no idea what started him limping, no obvious injury or anything.
He's been tot the vet's twice now, painkillers and antiinflammatories have not made any difference.
It's his right hind leg and the problem seems to be very intermittent: sometimes he properly tripods about, leg held high, no contact with the ground, sometimes he limps and very obviously favours the other leg, sometimes he seems to have no problem at all (and runs like the clappers) 
Next week he is going for an x-ray under sedation and blood tests (those are also to investigate his ongoing pooing and lack of weight gain further, but that's maybe a whole other thread).
Any experiences of lame mutts and what it turned out to be?
I am now a bit worried about him, he's too young for arthritis and hip dysplasia is uncommon in greys, but sarcoma is not.... 