That's pretty rude of your vet.... if I were you, I would call another vet in the area just to ask them what their thoughts would be.

YES they have arthritis medicine for dogs. I know they have some at PetCo and I can almost guarantee they'd have some at Petsmart too. They also have dietary supplements you can give your pups to help ease or prevent the full blown effects of arthritis.

Also you MAY be able to give your pup aspirin, but I don't recommend doing so until you call your vet (if he has the time for you, that is) to see if that is appropriate for your pup and what the correct dosage would be.

Hope I've helped, even if only a little!