Is weight loss typical of Hypothyroidism?

by Brenda Pietrzak
(Hamilton, Ontario, Canada)

My German Shepherd is just turning 6. 2 months ago he had 4 seizures in a two week span. Took his sugars at the time, as I am a Type 1 diabetic, and they were low.

I took him to my vet. They took his blood and sent it to a lab, for his sugar and Insulin level. They came back normal. We took more bloodwork last week for a CBC, and Chemistry work up. Also for a Pro BNP with profile. The CBC came back normal, the AST and liver profile, came back normal, the T4 was very low, and the Heart profile hasn't come back yet as it takes longer.

I had just put down my 9 year old, female Rottweiler in August/10 due to an agressive cancer, but she had been on thyroid pills, for 5 years. My vet suggested I put my shepherd on those pills immediately, as I had renewed her prescription one month before I put her down. Only she had gained a lot of weight, where as my shepherd is losing weight at a rapid pace. Especially in the face area. He's losing muscle mass.

My vet said it is like finding a needle in a haystack. If the heart test comes back high, we put him on cardiac drugs, if it's normal, then wait and see if the thyroid drugs work and his condition improves. If it doesn't improve, he is thinking either another autoimune disorder or a tumour.

I've had the same vet for twenty years, I trust him, but I am very worried as I had just put down my Rottie due to cancer, and I am terrified of losing my other baby due to the same disease in a span of 2 - 3 months.

My question is, is it a sympton of thyroidism in dogs to lose 25 lbs? In 2 weeks he lost 5 lbs. A total of 25. I'm talking his weight was 137 last year at his routine visit, compared to 118 now, 5lbs being lost in 2 weeks.

Yes, his appetite is very low and I have to convince him to eat. I took him off his dry dog food, and put him on the BARF diet, to try to build up his immune system.

Thank you,

Editor Suggestions, Weight loss and hypothyroidism

Dear Brenda,

No, weight loss is not a common symptom of hypothyroidism. In fact, just the opposite, weight gain, is typically seen.

There is a condition called canine sick euthyroid syndrome that could explain your dog’s low thyroid level. When a dog is very sick for any reason, the thyroid gland stops producing normal amounts of thyroid hormone. I think of it as the body’s way of slowing down its metabolism and conserving energy to deal with the problem at hand.

The blood test that is most often used to diagnose hypothyroidism cannot differentiate between true hypothyroidism and sick euthyroid syndrome. Thyroid pills do nothing to help dogs with sick euthyroid syndrome.

I’m afraid it is very likely that your dog is suffering from a fairly significant underlying disease. The only thing to do is to keep looking and hope that when you find the problem, it is something that can be treated effectively.

Good luck and please keep us up to date on your dogs condition!

Jennifer Coates, DVM

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