AmStaff 11 yrs old; severe hip dysplasia age 3, soft tissue cancer age 6, ACL/MCL age 8, you get the point. He''s in a lot of pain. He's had vet check, and bloodwork, everything's great, but his appetite is off, he occasionally gags, and his breathing has changed, it appears shallow, labored, and slightly rapid. Almost like ketoacidosis breathing. He's been on Tramadol since age 6. I normally give 1/2 tab - 25mg. And he has taken "drug holidays". I've told you all I've told the vet. Thank you for your consideration!