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Low Thyroid in Dogs: Symptoms and Treatment

December 15th, 2014 by Cherished Companions Animal Clinic

Ranger, Dr. Melanie's yellow Labrador, had the symptoms of low thyroid in dogs.

Today we want to explore a fairly common health issue: low thyroid in dogs.

Low thyroid disease can affect just about every dog breed, as well as both males and females.

It tends to be more common in middle-aged:

  • Golden retrievers
  • Labrador retrievers
  • Doberman pinschers
  • English sheepdogs
  • Boxers
  • Poodles
  • Cocker spaniels
  • And other mid- to large-size dogs

Ranger, a lovely yellow lab… with low thyroid

Ranger was one of Dr. Melanie’s favorite dogs…

An energetic yellow lab, Ranger loved playing in the water. During the summer, he’d even ride on wave runners with her!

At one point in his life, Ranger had surgery.

Soon after, Dr. Melanie began to notice an odd thing in the weeks after the surgery.

His hair wouldn’t grow back where Dr. Mel and her veterinary team had shaved him for the procedure.

He also was having unusual weight issues.

Even though Dr. Melanie was actively watching his food and activity levels, he was gaining quite a bit of weight.

So what was going on?

It turned out Ranger had low thyroid.

What is low thyroid in dogs?

Dogs with low thyroid disease have thyroids that don’t make enough of the hormones needed to keep their metabolisms up to normal.

Their metabolisms slow way down. The dogs:

  • Get heavy
  • Lose their energy
  • Become very lethargic
  • Start having issues with their coats of fur or hair (as was the case with Ranger)

Many dogs with low thyroid begin losing their hair, particularly along their tail and flank side.

Low thyroid in dogs can be genetic.

For example, in some dogs, it’s an autoimmune disease that runs in their family lines.

Once Wrigley started treatment for low thyroid in dogs, he was more comfortable.

Symptoms of low thyroid in dogs

So what are some symptoms that may suggest your dog has low thyroid?

Some of the common symptoms are a:

  • Sudden change in attitude and activity level – from being full of energy to having no energy
  • Sudden weight change without a significant change in food or activity level
  • Dry coat or hair loss

We can diagnose low thyroid in dogs with a blood test.

Typically, our veterinarians will send your pup’s test to Michigan State University for a full panel to confirm that the thyroid is the problem.

We’ll also consult with an endocrinologist.

Treating low thyroid in dogs

If your dog is diagnosed with low thyroid disease, we’ll likely recommend starting your dog on a special medication, so he or she feels better quickly.

You’ll have to give your dog a pill twice a day throughout his or her life…

But the great news is you’ll quickly see a dramatic and positive change in your cherished companion.

Typically, our veterinarians will check your dog’s “T4 level” about a month after you start the medication to make sure your dog is at the right level.

(The T4 level indicates the level of “thyroxine” hormone that your dog has.)

Then, we’ll likely check your dog’s blood level once a year in your annual visit, just to make sure your dog is doing well.

With the right care, low thyroid in dogs is a very manageable disease.

So back to the story of Ranger

Within a month of starting treatment for low thyroid, Ranger returned to his ideal weight.

He was back to his normal and crazy lab self.

He was playing in the water and jumping waves before Dr. Melanie knew it!


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Cherished Companions Animal Clinic is a veterinary clinic in Castle Rock, Colorado. Specializing in the care of cats and dogs, our goal is to help you and your pet feel more comfortable, keeping your stress to a minimum.

This article is intended to provide general information on low thyroid in dogs. If you have specific questions or concerns, please contact your local veterinarian. (If you live in or around Castle Rock, we welcome your call: 303-688-3757.)

© 2014, Cherished Companions Animal Clinic, All Rights Reserved

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