Introduction
Hyperthyroidism in cats causes a number of classic ‘hyperthyroid’ symptoms to develop. These symptoms are usually very mild in the beginning, and they increase in severity over time.
Symptoms of Hyperthyroidism in Cats
Increased Appetite
Hyperthyroid cats have increased metabolic rates, and as a result their appetite begins to increase. Even though hyperthyroid cats have a marked increase in appetite, they begin to lose weight due to increasing metabolic rates. Pet owners are often baffled at their cat’s increase in appetite, and wonder why their cat is eating so much but losing weight. The increased metabolism may also cause the cat to become much more active, or restless, in the beginning stages of the disease.
Increased Water Consumption
Cats with hyperthyroidism will also begin to drink a lot of water, and as a result they will begin to make increased trips to the litter box. In many cases, the gastrointestinal system is affected and the cat begins to show symptoms such as vomiting and diarrhea.
Enlarged Thyroid Glands
Some pet owners are able to feel the enlarged thyroid gland of their hyperthyroid cats. The two lobes of the thyroid gland are located on each side of the trachea near the top of the cat’s throat. As these lobes become enlarged, and the cat loses weight, they may become very prominent and noticeable.
Other Symptoms
Untreated hyperthyroidism will result in more severe symptoms which can include increased panting, weakness, lethargy or depression, anorexia, and heat intolerance. In some cases the cat’s heart rate may become erratic and congestive heart failure can occur.