Feline Symptoms of Underactive Thyroid Disease

An underactive thyroid (hypothyroidism) in cats is most often seen in middle-aged or older felines. Rarely occurring in cats, it can arise after overactive thyroid (hyperthyroidism) treatment, reducing a cat's metabolism. Several combined symptoms may indicate possible hypothyroidism in your cat, including vomiting, increased water intake and chronic ear infections. Visit your veterinarian for a possible diagnostic work-up if your cat experiences those symptoms in combination with weight gain, lethargy, skin disorders or bowel changes.

  1. Weight Gain

    • Cats may experience slower heart rates with hypothyroidism.

      Watch for signs of weight gain in your cat without an accompanying rise in appetite. The thyroid gland is responsible for producing and secreting thyroxine, which is responsible for regulating metabolism and growth. Weight gain may increase gradually, making it difficult to notice. Weigh your cat regularly each month and keep a weight chart. Weight schedules and charts can help you keep track of and watch for dangerous weight changes.

    Skin Disorders

    • Hair loss, especially on the tail or trunk area, could indicate hypothyroidism.

      Excessive hair loss or chronic dry skin without associated itching or thinning or dulling of the cat's coat could be indicators of skin disorders due to underactive thyroid glands. Watch for bald areas or an extreme amount of thinning. Even though skin disorders do not always indicate an underactive thyroid gland, they could slowly develop as the disease increases.

    Lethargy

    • Depression, agression and anxiety often go hand-in-hand with apathetic behaviors.

      Due to a reduced metabolism, cats may also experience apathy and lethargy. Since hypothyroidism is often over-diagnosed, make a note of your cat's mood and activity level in the weight chart to help you track and follow up on any changes. Watch for a reduced interest in play or an increase in sleeping patterns that are unusual for your cat.

    Bowel Changes

    • Constipation is often common in middle-age or older cats. If your cat spends an increased amount of time in the litter box or you notice your cat straining, seek your veterinarian's advice as to how to help this symptom. Diarrhea can also indicate an underactive thyroid condition. Cats often suffer constipation or diarrhea due to diet changes or low-quality cat food. However, if your cat experiences constipation or diarrhea without associated food changes, an illness could be present. Decreased appetite due to an underactive thyroid and constipation could go hand-in-hand.