I recently aquired a large lab/chow cross dog. He is older and seems to be pretty lame on his left front. I have made an appt. for him to see the vet but is there anything I can give him to ease his pain until his appt? Are there vitamins that he could be getting daily to help? He has been an outside dog for 13 years so Im thinking that its a combination of the cold and lack of excercise pretty much his whole life that has done it. Any advice?