Cat Cushings Disease
Veterinarian Reviewed on April 2, 2014 by Dr. Janice Huntingford
Cat Cushings Disease / Addison’s Disease
Signs and Symptoms
Cushing’s disease and Addison’s disease are both forms of adrenal gland dysfunction. While much more common in dogs, these disorders do occasionally affect cats. Feline Cushing’s disease is also known as hyperadrenocorticism and involves the overproduction of adrenal hormones. Particularly rare in cats, Addison’s disease often involves the production of antibodies that destroy the adrenal glands. This damage then results in the insufficient production of adrenal hormones. Although these diseases share several common symptoms, the warning signs for both conditions can be vague and variable. However, as the disease progresses, symptoms may become less subtle.
Two common symptoms of these diseases are increased thirst (polydipsia) and increased urination (polyuria). In the case of feline Cushing’s disease, the overproduction of steroids known as glucocorticoids can interfere with the animal’s ability to concentrate its urine. As a result, the cat urinates more frequently and is driven to drink more. The excessive amounts of these steroids can also cause the breakdown of muscle, leading to thin legs and a potbellied appearance. Weakness, lethargy, and apparent laziness are also common warning signs of cat Cushing’s disease. Appetite changes may also occur, frequently in the form of an increased appetite.
Some cats suffering from adrenal gland dysfunction also experience changes with their coats. For example, a cat’s fur may thin or display signs of slow regrowth. With respect to Cushing’s disease, hair loss and thinning most typically occur on the cat’s body, rather than on the legs and head. Calcified lumps may also develop under the cat’s skin. A cat with Cushing’s disease may also experience thinning of its skin, which can lead to tears and skin infections. Since excessive amounts of steroids can lead to immune system suppression, cats suffering from Cushing’s disease are also prone to secondary infections, such as those affecting the urinary tract. In addition, high blood pressure and panting are other warning signs that are exhibited in some cases. Both adrenal gland disorders are also capable of causing vomiting and diarrhea.
Since the symptoms caused by feline Cushing’s disease and Addison’s disease can be so vague and variable, it likely will not be readily apparent that adrenal gland dysfunction is responsible for your cat’s problems. Moreover, many of the symptoms and warning signs of these diseases can also be indicative of other medical conditions and disorders. If you observe your cat exhibiting any of the above signs, the best course of action is to have your pet examined by a veterinarian immediately. A professional diagnosis will reveal whether or not adrenal gland dysfunction is to blame for your cat’s unusual symptoms and behaviors.
When you take your cat to a veterinarian because it is displaying one or more of the above listed symptoms, the practitioner will go over your pet’s medical history and conduct a thorough physical exam. During the examination, the veterinary doctor will check for any of the common clinical signs associated with adrenal gland dysfunction. In order to make a definitive diagnosis, however, a number of laboratory tests and diagnostic techniques will likely be required.
Since there is no one single test used to diagnose cat Cushing’s disease, a number of blood and urinary tests may be performed. The levels obtained from such tests can then be compared to normal levels in order to determine whether or not adrenal gland dysfunction is occurring in the feline patient. Some of the most common changes that are observed in a patient with hyperadrenocorticism include elevated levels of white blood cells, increased blood sugar, elevated levels of ALP (a liver enzyme), increased cholesterol, and diluted urine. An ACTH stimulation test, which measures adrenal gland function, will also likely be carried out.
In addition to laboratory tests, other diagnostic methods that may be employed include imaging techniques such as x-ray and ultrasound. These tools can reveal the presence of calcium near the adrenal glands, which is suggestive of a tumor, or a tumor itself. X-rays may also show an enlarged liver or enlarged adrenal glands, both of which are indicative of adrenal gland dysfunction. In most cases where cat Cushing’s disease or Addison’s disease is suspected, a number of these tests and diagnostic tools will be used in combination in order to arrive at a definitive diagnosis.
Feline Cushing’s disease and Addison’s disease are both forms of adrenal gland dysfunction. A cat has two adrenal glands, which are located in its abdomen, just in front of the kidneys. Cushing’s disease is also known as hyperadrenocorticism and involves the overproduction of adrenal hormones. The primary hormone that is overproduced is the glucocorticoid cortisol. Cortisol is involved in many physiological functions, including the regulation of stress and blood sugar levels. Since this glucocorticoid plays a role in so many physiological tasks and pathways, excessive amounts of it can have a variety of effects. This is why the symptoms of Cushing’s disease can be numerous and varied.
Addison’s disease is extremely rare in cats, but it can occur. In contrast to Cushing’s disease, Addison’s disease is also referred to as hypoadrenocorticism and is characterized by insufficient production of adrenal hormones. Typically, this deficiency involves two groups of hormones — glucocorticoids and mineralocorticoids. Again, the major glucocorticoid is cortisol while the primary mineralocorticoid is aldosterone. Aldosterone is responsible for regulating the amounts of sodium, potassium, chloride, and water in a cat’s body. While Addison’s disease may occasionally affect only cortisol levels, it most often affects both groups of hormones. As with Cushing’s disease, the warning signs of Addison’s disease can be subtle and variable.
Feline Addison’s disease results from the destruction of adrenal gland tissue by the cat’s immune system. This most commonly occurs as a result of an autoimmune disease, where the cat’s body produces antibodies which then attack the adrenal glands as if they were a disease or infection. This disease is often associated with other autoimmune diseases, such as diabetes and thyroid disorders. Far less commonly, this type of adrenal gland dysfunction can be caused by cancer, infections, pituitary gland disorders, and medications. Sudden discontinuation of steroid medications, for example, may cause feline Addison’s disease. Therefore, animals should be slowly weaned of such medications.
Feline Cushing’s disease is typically caused by a tumor, either located directly in one of the adrenal glands (primary) or in the pituitary glands (secondary). A tumor located in one of the adrenal glands is less common, and directly causes the over stimulation of the gland and, therefore, the overproduction of adrenal hormones. On the other hand, tumors in the pituitary gland are far more common. These tumors cause an overproduction of the pituitary hormone that controls the stimulation of the adrenal glands. When this pituitary hormone is present in excessive amounts, it over stimulates the adrenal glands, thereby resulting in excessive production of adrenal hormones. Thus, while the secondary form of Cushing’s disease typically involves a tumor that affects the adrenal glands in a less direct way, this type of adrenal gland dysfunction is more common than the primary form. Feline Cushing’s disease can also be caused by the use of steroid medications, especially when such drugs are used over a long period of time.
The course of treatment required for an individual feline patient will depend upon the type of adrenal gland dysfunction that is occurring. In the case of feline Addison’s disease, corticosteroid and mineralocorticoid replacement therapy may be necessary. A daily salt supplement can also be helpful. With respect to treatment for cat Cushing’s disease, the form of the disease (primary or secondary) will play a role in the implementation of a treatment plan.
In circumstances where a cat is suffering from primary Cushing’s disease, the tumor on the adrenal gland generally tends to be malignant. As a result, the cancer needs to be treated in order to resolve the problems associated with Cushing’s disease. This may well require the surgical removal of the tumor. Once the tumor is successfully removed, the adrenal gland dysfunction is usually cured. However, this type of surgery is very delicate and risky and may not be appropriate for all feline patients with this problem. In contrast to primary Cushing’s disease, the secondary form of this disorder typically involves the presence of a benign tumor on the pituitary glands. As result, oral medications can generally be used to effectively treat secondary hyperadrenocorticism.
In addition to conventional forms of treatment, natural remedies can also be very helpful with respect to controlling adrenal gland function and reducing symptoms. The natural ingredients contained in such products provide a variety of benefits for cats suffering from Cushing’s disease or Addison’s disease. Natural substances such as Siberian ginseng and licorice help to balance adrenal hormones and adrenal gland function. Dandelion and milk vetch improve nutrition and the immune system. This is important for cats suffering from adrenal gland dysfunction, as their immune systems are often stressed, which can leave them vulnerable to other illnesses. As a result, many natural substances have properties that can promote the health and comfort of a cat experiencing adrenal gland dysfunction.
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Janice Huntingford, DVM, has been in veterinary practice for over 30 years and has founded two veterinary clinics since receiving her Doctor of Veterinary Medicine at the Ontario Veterinary College, University of Guelph. She has studied extensively in both conventional and holistic modalities. Ask Dr. Jan