These lobes are flattened and cannot routinely be palpated. Embedded in the front end of each thyroid gland are the parathyroid glands. It produces two hormones, referred to as T3 and T4 which circulate throughout the body and affect sensors on the organs of the body. Hypothyroidism is a condition where there is not enough thyroid hormone produced by the body and thus the metabolic rate slows down. Cats are rarely affected by hypothyroidism.
Hyperthyroidism results when the thyroid gland produces an excess of thyroid hormones.
This happens most commonly when the thyroid gland has become cancerous. Hyperthyroidism most commonly develops in cats over eight years old. Cats that are hyperthyroid are usually hearty eaters, sometimes even ravenous, yet they continue to lose weight in spite of how much they eat. This is first detected by an increased heart rate and confirmed by x-rays and ultrasound. Other signs can include increase thirst, increased urination, vomiting, diarrhea, behavioral changes and central flexion of the neck.