Blood tests reveal elevated thyroid hormone level and often elevated liver enzymes. Hyperthyroidism is due to an overactive thyroid producing excess amounts of thyroid hormone. This excess leads to an increase in metabolism. This results in weight loss, an elevated heart rate and often an increase in blood pressure. These cardiovascular changes can lead to anatomical changes in the heart itself.
Treatment is aimed at lowering the circulating levels of thyroid hormone.
Several treatment options are available. The best choice depends on the overall physical condition of the pet, availability of the procedure, veterinarians preference and owners financial situation. In the past surgical removal of one or both thyroid glands was a common approach. However this requires a general anesthesia in a cat that already has cardiovascular compromise and can also result in damage to the associated parathyroid gland. Most, but not all, cats tolerate this drug well.