Cat Hyperthyroidism-A Brief Introduction

As cat owners, there's nothing more distressing than finding out that your feline friend is sick. In the case of a disorder such as feline hyperthyroidism, the consequences can be severe and have the potential to rob your pet of its health, comfort, and even its life. However, when armed with some basic knowledge, you'll be better able to help your cat through its illness and to hopefully catch the problem early on so you can ease your pet's suffering and improve its health with early treatment and intervention.

The Feline Thyroid Gland

The thyroid is a double-lobed gland located in the cat's neck, wrapped around its trachea. Consisting of spherical follicles, this gland is responsible for secreting the two thyroid hormones -- thyroxine (T4) and triiodothyronine (T3). These two iodine-containing hormones play a significant role in a number of physiological functions and have an effect on every cell in the feline body. In particular, T4 helps to regulate the cat's metabolic rate, or the rate at which the cat's cells burn energy.

Feline Hyperthyroidism

When a cat's thyroid does not function properly and produces too much of the T4 hormone, the cat develops the endocrine disorder known as hyperthyroidism. This disorder is most common in middle-aged and elderly cats and affects male and female cats equally. Since thyroid hormones have an effect on every part of the feline physiological system, hyperthyroidism can also affect every organ. As a result, this endocrine disorder can have numerous negative effects on a feline patient and can quickly become extremely dangerous if left untreated.

Consequences of Hyperthyroidism

Since the thyroxine hormone controls the metabolic rate of a cat's body, elevated levels of this hormone result in a higher rate of metabolic function. This causes an increase in blood pressure as well as an increased heart rate. This excessive stress upon the feline heart can eventually cause it to expand in size. Known as myocardial hypertrophy, this heart condition causes the organ to wear out more quickly than a normal heart and will eventually lead to heart failure if the myocardial hypertrophy and hyperthyroidism continue to go untreated.

Symptoms and Warning Signs

The fact that cat hyperthyroidism affects every cell in a feline's body and increases the animal's metabolic rate explains the nature and high number of different symptoms that this disorder can give rise to. While not all feline patients will experience the exact same set of symptoms, some of the most common warning signs of hyperthyroidism include a significantly increased appetite accompanied by weight loss, both of which directly result from the elevated metabolic rate. Hyperactivity, irritability, rapid breathing, and a rapid heart rate are also frequently displayed by cats suffering from this thyroid condition.


While there are likely many different factors that can contribute to the development of hyperthyroidism in a particular cat, this thyroid condition is caused by the presence of a tumour on the thyroid gland. Even though these tumours are often benign, they still trigger the overproduction of thyroid hormones. When it comes to possible contributing factors for cat hyperthyroidism, there is still much that is not understood. However, it's believed that factors such as age, environment, and diet could be related to the development of thyroid tumours which lead to feline hyperthyroidism.


When hyperthyroidism is suspected in a feline patient, a thorough physical examination will be conducted so that the veterinarian can check for clinical signs such as enlarged glands, high blood pressure, and an elevated heart rate. Numerous blood tests can also provide important information on the condition of different organs and physiological systems. Thyroid tests will also likely be conducted in order to measure the levels of thyroid hormones in the cat's body. In certain cases, imaging tools such as ultrasound will also be used to examine the physical structure of the thyroid gland and to check for any physical abnormalities such as tumours.


Once a diagnosis of cat hyperthyroidism has been made, there are a variety of different treatment methods available. Traditional forms of treatment include surgery, radiation, and medication. A holistic health care approach will also be beneficial in some cases, involving the use of natural supplements and homoeopathic remedies to balance hormones and to regulate thyroid activity. Natural supplements are also beneficial in the sense that they can reduce uncomfortable symptoms and boost a cat's overall health. Whether your particular cat will benefit the most from a holistic health care approach or traditional treatment methods is something that will depend upon your individual pet's circumstances and will need to be determined by a veterinarian. For some feline patients, the best approach will involve a combination of both traditional and holistic treatments. In any event, it's always important to ensure that your feline friend receives treatment as soon as possible so that severe and potentially fatal consequences of this endocrine disorder can be avoided.

Article Courtesy of Article Cat

Author: Catharine Wells