So, you’ve just received the news from your veterinarian that your dog has hypothyroidism. Hypothyroidism is a relatively common endocrine abnormality in middle age and senior dogs. It is somewhat more common in spayed females and purebred dogs. Hypothyroidism is said to be the most common endocrine abnormality diagnosed in dogs in veterinary practice.
The thyroid gland is made up of two lobes, one on either side of the trachea (windpipe) in the center of the neck. It produces thyroid hormones, which regulate the metabolism. It is part of the endocrine system (glands without ducts).
There may not be a reason that your dog developed hypothyroidism. This is termed “idiopathic”. Some dogs become hypothyroid after inflammation destroys their thyroid gland. This tends to run in families of dogs, and may be genetically linked. Dogs that are diagnosed with hypothyroidism should not be bred.
The symptoms of hypothyroidism are not unique to this particular disease. Dogs suffering from a low thyroid hormone level are lethargic, gain weight easily, have dry skin and may lose their hair, and don’t like to be where it is cool or cold.
The diagnosis is made based on results of a blood test and clinical symptoms. A T4 is usually run first. Sometimes this test does not give a definitive answer and additional tests may be run if your veterinarian strongly suspects hypothyroidism.
Treatment of this disease is relatively simple and rewarding. Oral medication is given once or twice daily. This supplement must be given for the rest of your dog’s life. Within a few weeks, the symptoms of the disease should gradually disappear. Not treating this disease is not an option that should be considered. The symptoms will worsen and eventually death will result.
Once treatment is started, additional blood tests are run 4-6 weeks later. This is to determine whether your dog is taking the appropriate amount of supplementation. The dosage may be adjusted up or down based on your dog’s improvement and the results of the tests.
Prognosis for a full recovery is good with life-long supplementation.
Please note that this information does not replace onsite, professional, veterinary care. It is solely for educational purposes. Your pet's medical condition should be evaluated by a veterinarian before any medical decisions are implemented. If there is a potentially life-threatening emergency involving your pet, take your pet to a veterinarian or veterinary facility immediately.
Veterinary Technical Services Department