In 98% of cases, the enlargement of the lobe(s) is benign and non–cancerous. In these cases treatment and diagnosis are both straightforward and successful. In the remaining 2% of cases, the enlargement is due to a malignant cancerous growth of the thyroid gland.
Whatever the cause of the enlargement, the result is the same – more thyroid hormones are released.
If left untreated your cat may develop other serious conditions such as heart complaints and high blood pressure. Kidney disease, although not directly linked to hyperthyroidism, may develop at the same time since both diseases are common in older cats.
If you become concerned about your cat's health and welfare, you should consult your veterinary surgeon immediately.