Information on hyperthyroidism symptoms abnormal thyroid hormone levels in cats and dogs.

    learn about hyperthyroidism symptoms in cats and dogs

    Select a Topic

    1. What is Hyperthyroidism?
    2. What Causes Hyperthyroidism?
    3. Diagnosing Hyperthyroidism
    4. Help for Hyperthyroidism
    5. More Information on Hyperthyroidism

    What is Hyperthyroidism?

    Hyperthyroidism is an endocrine disorder that affects both humans and animals. When hyperthyroidism occurs, the thyroid gland is overactive is and produces too much thyroid hormone, speeding up the metabolism. The thyroid is a gland that consists of two small lobes shaped like butterflies with one each side of the windpipe (trachea) located in the neck.

    It produces thyroid hormones, thyroxine (T4) and triiodothyronine (T3). The primary function of these hormones is to regulate and maintain your pet’s metabolic rate which in turn affects their overall health and wellbeing. Another hormone called thyroid stimulating hormone (TSH) which is produced by the pituitary gland, controls the production of the thyroid hormones.

    Symptoms and signs of canine and feline hyperthyroidism include:
    • Weight loss even with an increased appetite
    • Diarrhea
    • Vomiting
    • Intolerance to heat
    • Dull, dry or oily coat with excessive shedding
    • Breathing difficulties
    • Increased water consumption accompanied by urination
    • Increased or decreased activity
    • Tremors

    Behavioral changes such as nervousness, restlessness, hypersensitivity or stress may also occur.


    What Causes Hyperthyroidism?

    When the thyroid gland is overactive, several parts of the body may not function properly, and your pet may experience drastic weight loss, appetite increase, an elevated heart rate, increased activity or poor skin and coat condition.

    Hyperthyroidism typically affects middle-aged to old cats (between 4 and 22 years of age). Hyperthyroidism in dogs is rare. It is caused by a benign increase in the number of thyroid cells produced. Immunological, environmental and nutritional factors may also contribute to this disorder.

    Diagnosing Hyperthyroidism

    The diagnosis of hyperthyroidism in cats and dogs is based on the symptoms presented – your vet will be able to feel the enlarged thyroid gland. Certain diagnostic tests such as T4, complete blood count (CBC), serum chemistry and urinalysis may be performed to check thyroid levels and rule out other conditions.

    In addition, tests such as the T3 suppression test, measurement of free T4 and thyrotropin-releasing hormone stimulation test may also be performed to confirm the diagnosis of hyperthyroidism.

    Help for Hyperthyroidism

    The following standard treatments for hyperthyroidism are usually recommended and these include radioactive iodine (I-131) and anti-thyroid medication such as methimazole (tapazole). In more severe cases, surgery (thyroidectomy) may be required. These treatments have some adverse side effects such as liver damage, anemia, hair loss and lethargy, and cats with this problem should be kept away from pregnant women and children.

    More Information on Hyperthyroidism

    Tips to cope with hyperthyroidism

    There are several things that you can do to cope with hyperthyroidism in pets and these include:

    • Feed your pet a natural, raw and well balanced diet that contains all the essential vitamins, minerals and nutrients
    • Ensure that your pet gets regular exercise
    • Boost your dog or cat’s immune system with immune-boosting supplements
    • Take your pet to the vet for annual check-ups and monitor any abnormal physical and behavioral changes
    • If your pet suffers from a thyroid problem, become as knowledgeable as possible about this health problem