Why is my 7 yr old Pom losing his undercoat/hair

[debgass]

Hi
We have a 7 year old registered Pomeranian, Kimo, who has been losing his hair over the last 2 years. It started in his rear and tail and has now moved up his back and neck. He still has his beatiful coat on his head/mane and front legs.
Our Vet, based on blood tests, thought it may be from an underactive thyroid. He has been on medication for over 2 years and it's just getting worse.
We recently changed his diet to a non-allergenic food of duck and potatoe thinking he had food allergies.
Do you have any suggestions?
Thanks.
Deb

[debgass]

Hi Val
Thanks for the information. Our next step, if the change in his diet does not produce positive results, will be to take him to a dermatologist.
I would not want to affect his health just for him to have hair. There is no odor, bumps or rashes.
Deb

[vallieanne]

Hi,
I had a Chow Chow who lost her hair on her tail and around her neck and the regular vet tried many things to figure out what is was, he ended up having me take her to a veterinary dermatologist. She did a skin biopsy on her and it came back as a rare disease called pemphegis, which was an auto-immune disorder.
She was put on immuno-supressents and predinsone and the hair did come back, but the side effects of the drugs were very hard on her internal organs. Thankfully, she was already 12 when this started, and she made it to almost 15 before she passed away.  The best thing I can tell you is take the dog to the dermatologist to get a second opinion and let them do a biopsy, it could be coming from several different things that cause hair loss and the only way to find out is to keep ruling things out.
Does the dog have any kind of unusual odor coming from the skin where there's no hair and are there any little bumps or rashes?
Valerie

[debgass]

Thanks for your response.
Kimo's hair loss is bilateral all along his back. His legs have normal hair and undercoat. Can you tell me how Cushing's Disease is treated?
Kimo also has a heart murmur and is taking medication for his underactive thyroid which the vet believes may be the cause of the hair loss. He does seem to be bothered by it, no excess scratching or such but he does like to be scratched.
Deb

[Ghilly]

Is the hair loss bilateral?  In other words, is he losing it in the same places on the right side as he is on the left?  Hair loss could also be a symptom of Cushing's Disease, which is caused by a tumor on the pituitary gland.   If he hasn't yet been tested for this, I would do it to also rule this out.

Ghilly

[Jaybay]

I sure wish I could help you on this one, but I've never personally dealt with a coat problem that went unexplained.  It might be time to ask your vet for a referral to a specialist - either dermatology or internal medicine or both.  Obviously this case isn't going to be an easy fix, and a firm diagnosisis going to take some time and money.  Does Kimo have any other health issues?  Hopefully one of our other members will have some ideas for you, and you can also post your question to Dr. Cheng on the Ask a Vet forum.  Best of luck!  :-)