By Dr. Becker
Addison’s disease, also known as hypoadrenocorticism, is a disease of the adrenal glands. It is much more common in dogs than cats, but it does sometimes occur in kitties.
In Addison’s disease, the adrenal glands produce fewer corticosteroid hormones than the body requires. The adrenals produce the hormones responsible for the fight-or-flight response, which is how an animal’s body copes with potential danger or stressful events.
These potent stress hormones are designed to be produced in small amounts only when the body is being threatened. But sometimes the adrenal glands become overworked and can no longer produce all the hormones the body is asking for. If the adrenals continue to under-produce stress hormones, adrenal insufficiency – otherwise known as Addison's disease – develops.
Causes and Symptoms of Feline Addison’s Disease
When hypoadrenocorticism occurs in cats, it’s usually caused by atrophy of the adrenal glands due to an autoimmune problem in which the cat’s immune system begins attacking its own tissues. Other suggested causes of Addison’s in cats include the use of corticosteroid drugs, cancer, trauma or mineralization of the pituitary gland, internal hemorrhage, infection, and granulomatous disease.
Kitties with Addison’s may not show any obvious signs of illness. When they do, the symptoms can be fairly generic, and can come and go for no apparent reason. They include weakness, lack of energy, loss of appetite, increased thirst and urination, vomiting, and sudden collapse. Sudden collapse is actually fairly common in cats with hypoadrenocorticism. If you have a kitty who is lethargic, sluggish, or just can’t seem to get up at all, you need to be thinking Addison’s.
In cats with the condition, levels of circulating electrolytes – such as potassium, sodium, and chloride – become imbalanced, which can lead to dehydration and other serious problems. These symptoms are typical of many other feline diseases, and since Addison’s is fairly rare in cats, it often goes undetected as your veterinarian searches for other more common causes for your pet’s illness.
Hopefully your vet has Addison’s disease on his or her radar as a potential cause of your kitty’s symptoms.
After taking a history and completing a physical exam to look for clinical signs like dehydration, a weak or slow pulse rate, irregular heartbeat, generalized weakness, or depression, your veterinarian will probably perform a complete blood count and serum chemistry profile, along with a urinalysis. These tests can reveal a lot about the function of your cat’s organs, but alone, they don’t confirm a diagnosis of Addison’s disease. Based on those test results, your vet may also recommend chest X-rays, an abdominal ultrasound, or other procedures to try to determine the cause of your kitty’s illness.
The confirming test for Addison's is an adrenocorticotropin hormone (ACTH) stimulation test. In this test, blood samples are taken before and after the cat is injected with an adrenal-stimulating hormone. If your cat does not have Addison’s, the blood cortisol levels will increase. If she has Addison's, there will be no increase in blood cortisol, which is the confirming diagnosis.
Treatment Options and Long-Term Management of Feline Addison’s Disease
How aggressively your cat’s illness is treated will depend on her clinical status. Acute Addisonian episodes are true emergencies that require immediate veterinary intervention – sometimes even before a diagnosis is confirmed.
If your cat is very sick, she will need to be hospitalized to receive IV fluids and cortisol replacement agents. While dogs often show good improvement within the first 24 hours after initiating treatment, sometimes kitties don’t respond that quickly. It can be three to five days or even longer after treatment begins before improvement is seen in a feline Addison’s patient.
Once your pet’s fluid levels are normalized and hormone levels are stabilized, she has received initial fluids and medications (sometimes including IV glucose), and she has recovered from any other adverse effects of the Addisonian crisis, you’ll be able to take her home.
Long-term management of Addison’s disease usually involves oral supplementation with adrenal corticosteroid hormone replacement for the rest of the cat’s life. Addisonian kitties should also have regular urine and blood tests to monitor the level of adrenal hormones and other substances, such as electrolytes, circulating in the blood. If elevated potassium levels persist, additional drug therapy may be required.
Preventing all forms of physiologic stress can help your cat avoid adrenal gland disorders like Addison’s disease. Start by reducing nutritional stress with a balanced, species-appropriate diet that is moisture-dense and grain-free. Don’t allow your cat to be over-vaccinated, as this is tremendously stressful to the immune system and can set the stage for an autoimmune reaction.
Reduce or eliminate situational stress by enriching your cat’s environment. There are a number of ways to do this – please refer to my videos and articles on the subject here at Mercola Healthy Pets. Keeping a regular schedule that minimizes risks for sudden changes or other unexpected stressors is wise for all kitties, but is especially important for Addisonian kitties.
Talk to your holistic veterinarian about glandulars to nourish your cat’s adrenal glands, as well as adaptogenic herbs and nutritional support that might be beneficial. At my animal hospital, we use whole food supplements and adrenal glandulars to help reduce the amount of drugs needed to manage Addisonian patients, as well as a homeopathic preparation of cell salts called Bioplasma, which helps regulate electrolytes.
Finally, make sure that your cat is getting some exercise and playtime each day, which will help support healthy cortisol levels.