Hypothyroidism in dogs Sympoms and Tratment

Hypothyroidism is a common malady in many pure bred dogs. Find out what the warning signs are and how to treat this hormone deficiency in your pet.


Has your dog suddenly gained excessive weight even though he’s eating little?

Is he reluctant to exercise? Has he experienced hair loss or a dull coat? Does his skin look flaky and/or irritated? Are his eyes droopy or his joints stiff? Does he smell, no matter how often you bathe him?

If so, your pet might have a common malady called hypothyroid disease. Hypothyroid is when your pet’s thyroid gland, which is located in the neck, ceases to produce the thyroid hormone needed to regulate metabolism. The thyroid hormone is produced and stored by the thyroid gland, and a reserve is also stored within the animals skin. The symptoms of the disease can develop over a long period of time. Many canines exhibit signs at about 2 to 3 years of age, but typically the disease does not progress or become apparent to owners until much later.

At first the pet might experience what appears to be seasonal hair loss or irritation, altered appetite and some lethargy, but these symptoms often come and go, due to the fact that in the early stages of hypothyroidism, the thyroid gland may still be producing moderate amounts of the hormone. Enough to keep them looking healthy, enough to mask the fact that a more serious problem may be developing. During middle age, the gland eventually wears out, and ceases to function all together. At this point, the signs and symptoms accelerate and become obvious, seriously affecting the quality of the pets life. In cases that are left untreated, the animal can die. Many owners are now requesting that thyroid tests be done early in their pet’s life, especially in breeds that may be prone to the disease.

Hypothyroidism is common in many pure breed dogs, such as: Akitas, Dobermans, cocker spaniels, golden retrievers, sheep dogs, and some terriers. Cats rarely get hypothyroidism, and are more likely to suffer from HYPERthyroid maladies, which is an overabundance of the thyroid hormone.


1 Weight gain – loss of appetite
2 Skin problems - dandruff, flakiness and irritation
3 Hair loss
4 Lethargy
5 Droopy eyes
6 Stiff joints
7 Intolerance to cold
8 Sudden aggressive or uncharacteristic behavior (depression)
9 Mentally slow or inattentive
10 Pervasive, yeasty smell coming off of the skin

It’s important to keep in mind that a dog may not have all of the symptoms, and the degree of each symptom that they DO have will be varied. Many dogs also suffer from skin infections, or what seem like skin allergies as a result of the dry skin condition caused by the lack of the thyroid hormone. This can manifest in the dog causing itching, chewing and scratching, increased hair loss and in some cases where the dog worries an irritated area, sores and bleeding. Hypothyroidism is often treated incorrectly as a skin allergy in its early stages. Before allowing a vet to treat your pet’s symptoms as an allergy, and administering cortisone treatments, it is advisable to ask for the thyroid blood test FIRST, to rule out possible thyroid problems. Failing to do so, can waste needless money on ineffective treatments long term.

To diagnose the disease, owners must take their dogs in and ask the vet to administer a thyroid blood test. This test will determine whether or not the pet’s thyroid levels are low. The test most widely used, is the T4 test, which measures the level of T4 hormone in the blood. If this hormone is low, it’s a safe bet that your pet’s thyroid gland is not functioning properly. This test is quite inexpensive (approx $38 to $50 dollars, depending on your vet and the lab services he or she uses) but is not 100% accurate. Newer tests are now available, the most accurate being the THS response test, but it is more complicated to administer and therefore, considerably more expensive. A chemical is injected into he dog, then the blood is tested to see if and how the dogs thyroid gland responds to the chemical administered. The obvious problems with a poor diagnoses, is that if the animal is given too much hormone, he can become agitated and hyper, and too little hormone will not cure the dogs of his symptoms.


Fortunately, low thyroid is easy to treat once accurately diagnosed. The dog is prescribed a manufactured thyroid hormone called Thyroixine, or Soloxine, and it is administered in the form of a pill, often in two daily doses. The pill is inexpensive, and a typical monthly supply is around $10 to $15 dollars. The dog will have to take the replacement hormone for the rest of their lives to maintain normal hormone levels within their system. If the dosage is correct, owners will generally see improvement in a week to two, depending on how severely depleted their levels were prior to treatment. Most vets will require that the dog come back in within 4 to 6 weeks for a follow-up blood test to make sure the dog is being given the right dosage for their thyroid needs.