Low Thyroid Levels in Dogs

Low thyroid levels in dogs cause a condition known under the name of hypothyroidism. This condition can be corrected once detected, but the dog’s thyroid levels should be constantly monitored. There are a few underlying conditions that may lead to low thyroid levels.

Causes of Low Thyroid Levels

The thyroid hormones (T3, T4 and TSH) form in the thyroid glands. The hormones are important in the metabolism process. The thyroid glands are part of the endocrine system and will secret these hormones on a regular basis. When the thyroid glands are injured, destroyed or affected by a tumor, the hormones secreted will be in deficit.

The thyroid glands may also function in deficit if the dog has a problem affecting the hypothalamus or the pituitary gland, which are also part of the endocrine system.

Dogs that receive treatment for hyperthyroidism may often experience low thyroid levels, due to the treatment.

Symptoms of Low Thyroid Levels

Low thyroid levels may result in several symptoms that are easy to spot:

  • An increase of body weight in a short period of time, due to the fact that the metabolism of the dog doesn’t function properly. The dog may eat the same amount of food or even less and still gain weight
  • Lack of appetite
  • Poor skin and coat condition
  • Itchy skin and flakiness
  • Alopecia or hair loss
  • Lethargy
  • Low body temperature
  • Pale gums
  • Low pulse
  • High level of cholesterol

The symptoms may be absent, especially if the dog has only a slight deficit of thyroid hormones. However, if there is a severe lack of thyroid hormones, the dog will most likely display 2 or several of the above mentioned symptoms.

Diagnosing Low Thyroid Levels

The levels of T3, T4 and TSH can be measured with a blood test. The vet will also choose to perform a TSH stimulation test.

The normal levels of thyroid hormones depend on the dog’s age, breed and size, so only a vet can determine if your dog has low thyroid levels.

Treating Low Thyroid Levels

If the diagnosis is clear, the vet will prescribe thyroid gland stimulants or artificial hormones such as Thyroxine. The dose will be established in line with the test results. However, the dose should be adjusted several times during the treatment, as the dog may easily develop hyperthyroidism. The treatment may be needed for the rest of the dog’s life, depending on what are the causes of the low thyroid levels. In some cases, treating the underlying condition will normalize the thyroid hormone levels. However, until the treatment for the underlying condition is administered, the dog will have to receive synthetic hormones to prevent complications.

Regular checkups will be necessary to adjust or discontinue the medication treatment. Typically, dogs that have low thyroid levels will have recurrent periods with low thyroid levels.