http://www.ainsworths.com/site/default.aspxWe are having the same problem with our pup, but he's lame on his right hind leg. The vet took 2 separate sets of x-rays but couldn't find anything abnormal. They are suspecting slipping patella because toy breeds are predisponed to this condition.
What breed is your dog Caroline?
Have you noticed is its worst when it's cold and wet? after sleeping? is the dog lame all the time or is it intermitten? is the dog in pain and/or discomfort?
I wouldn't personaly like to give medication to my dog without knowing what's wrong :-(
Our dog's been lame since January, he had a period of one week when he stopped limping and his limping is intermitten.
I will speak with the vet regarding hydrotherapy or acupuncture next week.
Hope it's nothing serious with your dog and hope it gets better soon:-)