Thanks everyone. Dr. Kim managed to get ahold of the pathologist right away. So he was able to get back to me faster. It's mixed news.

It appears that Earle's pituitary gland is not working. That gland produces the thyroid stimulating hormone which in turn tells the thyroid to produce it's hormone. The pituitary gland does a host of other things as well and pretty much everything goes all screwy if it shuts down.

There are a number of reasons that could cause this problem. None of them are easy to diagnois. Most would require testing my vet doesn't have access to--like an MRI of Earle's brain. It is possible that he has a tumor on the pituitary gland or a brain tumor, which is what I believe killed Hoodoo. However, my very sweet, patient and highly competent vet tells me this is unlikely. There's also no point worrying about it as there is no way to prevent it or treat it if he did have brain cancer!

The pathologist has recommended treating Earle with thyroid pills, the same stuff Preacher takes. He will be starting his twice daily dose tonight. He should start to feel dramatically better within 2 weeks. In a month, he goes in to get weighed and checked over again. If this works, he will need the medication for the rest of his life, but he should have a normal life span and more importantly, be back to being my happy boy again! If he doesn't respond to the medication, it's back to the clinic for more testing to eliminate autoimmune diseases, but Kim is pretty confident this will work.

He was very specific that when Earle starts to feel better I have to keep him quiet and no harness work. Kim just had to send another dog to a specialist clinic down south for ACL repair surgery. That dog was also hypothyroid and when the meds kicked in, he felt so good he was too active and blew his knee out! Earle can return to harness work, if he so desires, when his weight is back to normal and his joints are under less stress. A sled dog should not weigh 83 pounds! I don't particularly care if he ever pulls again. I just want him around for a long time and I want him happy!