Hyperthyroidism in cats is a common endocrine disorder, primarily affecting middle-aged and older cats. It is caused by the overproduction of thyroid hormones (T3 and T4) from an enlarged thyroid gland, usually due to a benign tumor called an adenoma. This excess hormone production leads to an increased metabolic rate, causing symptoms such as weight loss despite an increased appetite, increased thirst and urination, vomiting, diarrhea, hyperactivity, and an unkempt coat. If untreated, hyperthyroidism can lead to serious complications such as heart disease and high blood pressure.
Causes and Mechanism
Hyperthyroidism occurs due to enlarged thyroid glands producing excessive thyroid hormones. Most cases involve a benign tumor (adenoma), while a small percentage are due to malignant tumors. The exact cause is unknown, but potential factors include dietary issues and environmental chemicals.
Clinical Signs
- Weight loss despite increased appetite
- Increased thirst and urination
- Vomiting and diarrhea
- Hyperactivity or nervous behavior
- Unkempt or greasy coat
- Increased heart rate and sometimes a palpable thyroid nodule
Diagnosis and Treatment
Diagnosis is usually confirmed by blood tests measuring thyroid hormone levels. Treatment options include medication, radioiodine therapy, surgical removal of the thyroid gland, and special iodine-deficient diets. Most cats respond well to treatment and can lead a normal life afterward.
Complications
If untreated, the condition may progress to heart disease (hypertrophic cardiomyopathy), high blood pressure, and damage to various organs including the eyes, kidneys, and brain. This information provides a comprehensive overview of hyperthyroidism in cats, its causes, symptoms, complications, and treatment options.
