Q&A: with Dr. Leilani Alvarez on Cushing’s Disease in Dogs
Cushing's disease appears when the body overproduces certain hormones, especially cortisol.
This leads to increased appetite and thirst, lethargy, and a pot-bellied appearance. Because some of the underlying causes of the disease could be related to pituitary or adrenal tumors, early treatment is essential for a favorable outcome. “Dogs can absolutely live a very full and long life despite having Cushing’s disease,” according to Dr. Leilani Alvarez, DVM, DACVSMR, Director of Integrative and Rehabilitative Medicine at the Animal Medical Center of NYC. “And when Cushing’s is actively being treated, we don’t expect the disease to continue progressing.” While there’s no way to predict if your dog will get Cushing’s disease and no way to prevent it, there are things you can do if you suspect your dog is sick. We talked to Dr. Alvarez about Cushing’s Disease and how it can affect your dog.
THE HONEST KITCHEN: What is Cushing's Disease and how does it affect dogs?
LEILANI ALVAREZ: Cushing's Disease is a condition where the body produces excess amounts of cortisone (a natural steroid produced in the body). This can occur when hormone-producing glands either near the kidney (called "adrenal glands") or in the brain (called the "pituitary gland") produce too much cortisone. The medical name for the disease is hyperadrenocorticism. The vast majority of dogs with Cushing's (80-85%) have it due to a tumor in their pituitary gland. A smaller percentage of dogs (15-20%) have adrenal tumors that cause Cushing's. Cortisol-producing tumors in the adrenal or pituitary gland can be either cancerous or benign. Cushing's can also be caused by chronic or excess use of medications containing steroids (called iatrogenic Cushing's).
THE HONEST KITCHEN: What are the most common symptoms of Cushing's disease in dogs?
LA: The most common symptoms include increased thirst and urination, increased appetite, thinning hair coat, pot-bellied appearance, excessive panting, and muscle weakness. Not all dogs demonstrate all these symptoms and severity can certainly vary as well. Consider taking your pet to the vet if these symptoms are persistent or your pet seems uncomfortable or not herself.
THE HONEST KITCHEN: Does nutrition play a part in the development of Cushing’s?
LA: The vast majority of dogs with Cushing's syndrome are due to an adrenal or pituitary tumor; however, a small percentage of dogs (<5%) may be due to an inherited condition. These dogs are born with abnormal cells that release an excess amount of steroids in the adrenal gland in response to signals from the stomach after a meal (abnormal glucagon inhibitory peptide—GIP). This leads to chronic transient increases in cortisol from a young age and can present with the same classic symptoms of Cushing's. These dogs can have normal tests for Cushing's unless the test is done ~ 4 hours after a meal. When a dog with "meal-induced Cushing's" is fasted for 12 hours, the test results will be normal.
THE HONEST KITCHEN: Can changes in diet affect Cushing’s, either positively or negatively?
LA: I am not aware of any valid scientific literature demonstrating that diet affects Cushing's either positively or negatively (except for the rare cases with abnormal GIP adrenal receptors). Nonetheless, a healthy diet is always beneficial for dogs with any type of chronic disease.
THE HONEST KITCHEN: Can you explain why a whole foods diet would be more beneficial for a dog with Cushing’s?
LA: From a Traditional Chinese Veterinary Medicine (TCVM) perspective, diets that are rich in carbohydrates and dairy would be more "dampening". In loose terms, this means more "inflammatory". For example, diets that are highly processed or SOMETHING OTHER THAN KIBBLE-type and foods containing milk, cheese, or other dairy could be more pro-inflammatory and lead to symptoms of "bloating". Given that Cushing's Syndrome can cause similar symptoms, one could use a TCVM approach and avoid these types of foods in an effort to reduce these symptoms. In order to ensure a complete and well-balanced diet, consumers should look for an AAFCO label on the food.
THE HONEST KITCHEN: Is a high protein diet recommended for dogs with Cushing’s?
LA: I am not aware of any reliable sources that indicate higher protein diets are better for dogs with Cushing's. In general, it's best to look for proteins sources that are whole (as opposed to meal or other more processed particles that contain protein).
THE HONEST KITCHEN: Should Purines be avoided for dogs with Cushing’s?
LA: I'm not aware of Purines being linked with canine Cushing's syndrome. Any Honest Kitchen diets that are complete and balanced would be appropriate. I personally like to feed dogs with Cushing's diets are more "damp draining" from a TCVM perspective. These would include Grain-Free Fish and Limited Ingredient Fish (formerly Zeal and Brave) and Grain-free Turkey (formerly Embark).
THE HONEST KITCHEN: Can Cushing's be cured or just managed?
Cushing’s can be cured if treated surgically. Meaning that the tumor is removed and there is no longer excess amounts of steroids produced in the body. The surgery can be risky, however, given the close proximity of the adrenal glands to major blood vessels (the vena cava) and the kidneys. Pituitary tumors are even less commonly treated surgically since that would involve brain surgery! More commonly, Cushing’s is managed with medication. In the old days, we used a medication called Lysodren, which actually destroys the cells in the adrenal gland that produce steroids. This treatment could also be risky because if too much medication was given, the damage was irreversible could lead to a crisis since some amount of steroid production is necessary for everyday life’s stresses. Without the body’s ability to produce cortisol in response to stress, animals can collapse and even die. Nowadays, thankfully, there is a much safer medication, called Trilostane, that blocks an enzyme rather than destroying any cells. This allows us to tweak the dose up and down as necessary or even stop the medication all together, making it an overall very safe treatment option.
THE HONEST KITCHEN: Are there any supplements you recommend for dogs with Cushing’s?
LA: For atypical type Cushing's (when cortisol levels are normal but there is abnormal secretion of sex hormones), flax hull lignans can be a useful supplement. Lignans have natural phytoestrogen activity and complete for estradiol receptors in the body. Melatonin can also be helpful, especially if hair loss is a symptom. TCVM herbal formulas with damp draining effects and/or Yin balancing formulas can also be useful.
Diana Bocco is a full-time writer and avid adventurer. She's gone hiking in Siberia, snorkeling in Thailand, and canoeing in the Mekong River. She also loves caves and has been known to get lost in one or five around the world. Diana's work has been published in the Discovery Channel website, Yahoo!, Popular Mechanics, and more. You can read more of her work on her website at www.dianabocco.com