Hyperthyroidism in cats is a common diagnosis that is rarely seen in dogs.
The thyroid is a gland that produces hormones, triiodothyronine (T3) and tetraiodothyronine (T4). The hormones are stored in the gland until they are needed by the body. T3 and T4 control all of the body's metabolic processes. Hyperthyroidism is a common endocrine disorder in cats while hypothyroidism is more common in dogs.
What is hyperthyroidism – Hyperthyroidism is an over active thyroid gland. When the thyroid gland spits out too much T3 and T4 many of the body's organs are affected and the cat can become very ill. Many times the thyroid becomes over active because of an enlargement of the thyroid gland due to a noncancerous growth. Thyroid cancer is rarely seen in cats, comprising 1 – 2% of all cases of hyperthyroidism in cats.
Symptoms of hyperthyroidism – Hyperthyroid disease is primarily seen in older cats. Symptoms include but are not limited too: weight loss, an excessive desire to eat – these cats are always at their food bowls, vomiting, fast heart rate, aggressive behavior, enlarged thyroid gland that the veterinarian can palpate, increased systolic blood pressure, and blindness.
Diagnosing hyperthyroidism in cats – Diagnosis is quite easy. Many times the veterinarian can feel the enlarged thyroid in the cats neck, some veterinarians will check for this during routine physical exams. If the doctor suspects hyperthyroidism in your cat he/she will do a blood test to check the level of thyroid hormone in the cats blood. If it is high then the cat has hyperthyroidism. The veterinarian might want to run additional blood work to check the bodies organ function, for example the kidneys and liver, and check for hypertension by taking the cats blood pressure. Hyperthyroidism can be hard on the body, especially the heart because of the fast heart rate it causes and medication may be needed to control heart disease and high blood pressure.
The cause of hyperthyroidism in cats is unknown but there are treatment choices available through your veterinarian. All hyperthyroidism cats should have regular blood pressure checks as well as blood work and EKG's to check heart function.
Treatment of Hyperthyroidism in cats