Golden in trouble

Question
My golden retriever was in the yard all day with a playmate of his one day. He has been doing this for a month now with the other dog. That evening, our dog was like a completely different animal. Where he was once the most loving care-free dog I've ever had, he now was shy, didnt want to go out in the yard, doesnt care to eat anymore and sometimes refuses to go out to go potty. He has developed a limp where he wont put one of his paws down and is mortififed when we want him to go in the backyard. We took him to the vet and could find no signs of a bite and was given an anti-inflammatory. An x-ray was also taken and was negative. After 3 days with things getting worse, he prescribed an anti-anxiety medication. It has now been almost 2 weeks and things are no better. I am prepared to take him back to the vet but would listen to any advice you might have.

Ken

Answer
Your dog suffered an injury and your veterinarian (for whatever reason) is unable to identify it.  Find an orthopedic specialist, but also have some blood work done to ward off the possibility that the dog was bitten (by an insect or snake).  It's obvious this is an occult injury of some sort; even a spinal tap might help and the dog might require an MRI.  I see you are a very caring owner; have patience, he's frightened, in pain and it might take some time to get to the cause.  Never stay with a veterinarian who makes summary judgments.  Good luck.