I am drawing a blank on the name and lab that runs the extended thyroid test. My friends BC has been being a bit more "cranky" lately (he bit one of her other dogs a week or so ago and he tries to bite when she is grooming him). She said something to the vet when she took the dog in that was bit and the vet said "it might be time to think about letting him go" (be PTS).
I asked my friend one question: Has this gotten worse as his weight increased? She said yes. I said before you make any rash decisions, have his thyroid checked. I know the regular test the vet uses is limited and with the possible outcome from this test she wants to have the more thorough testing done.
Lazer was abused as a pup with a cracked skull and jaw and suspected brain damage. It IS possible that this is a result of those early injuries but he has been through so much he deserves a relatively simple test.
If you haven't already had it done, be sure that they include the TgAA (thyroglobulin antibodies). Many won't include it, even when you asked for a full panel. That's the one that has the best chances of catching any autoimmune component.