About 3 months ago my Black lab started slowing down and having trouble getting up, going up stairs and walking. He has been to 2 different vets and been on everything from muscle relaxors to steroids to antibiotics because of a temp of 104. He had x-rays that showed only very minor arthritis and his labs were all normal. He refuses to eat but drinks water. I try to get him to eat anything but he won't. Any help would be great.