Symptoms of Thyroid Disease in Dogs

Dogs with thyroid disease lack adequate thyroid hormones to maintain normal functioning. The thyroid affects the rest of the bodily symptoms, making thyroid disease hard to diagnose. Dogs with thyroid disease go through a number of sometimes contradictory symptoms including weight gain, hair loss and personality changes. Dogs may suffer from problems with any of their bodily systems, including digestion and reproduction.

  1. Weight Gain

    • Thyroid disease typically causes dogs to gain weight. However, not all overweight dogs have thyroid disease. Many simply eat a too-rich diet or exercise too little. If your dog has recently gained weight, take him on additional walks and switch to a lower-calorie pet food. If he doesn't lose weight, you may want to talk to your veterinarian about thyroid disease.

    Lethargy

    • Dogs with thyroid problems tend to become lazy and lose their tolerance for exercise. They may sit all day, resist walks or ignore attempts to play. Your dog may lack energy to do basic tasks such as eating or drinking very much. He also may eat or drink more slowly than usual.

    Skin and Hair Changes

    • Hair changes caused by thyroid disease include hair loss on head and limbs and at the base of the tail, thin hair, or a dull coat. Skin changes include thick scales, known as hyperkeratosis, and dark spots known as hyper-pigmentation.

    Personality Changes

    • Thyroid disease can cause pets to act very different from their normal behavior. Once playful dogs may become mean or aggressive. Once bold dogs may become fearful. Dogs will lose mental alertness and have trouble learning new tricks or remembering changes in their environment. Training a dog with thyroid disease may seem impossible.

    Other Problems

    • Dogs may suffer from cold intolerance, high cholesterol or ear inflammation. Since all bodily systems require a functioning thyroid to do their best, any one system may suffer. Dogs may be unable to procreate, may suffer from digestive ailments such as diarrhea, or may suffer from circulatory problems such as a slow heart rate.