For some dog owners, Cushing’s is a disease they have had to deal with in their pets. For those who have no prior experience with the condition, Cushing’s is a disease involving the adrenal glands.
The adrenal glands produce cortisol and hormones that affect the body’s daily functions. Two of them are small glands. One is at the top of each kidney. They help regulate metabolism and affect blood pressure, and they respond to stress and even secrete certain sex hormones. So, while they’re usually small and relatively unnoticeable when they’re working, they can cause quite a stir if they’re not working properly.
Cushing’s is named after Harvey Williams Cushing, a neurosurgeon who first described the condition in humans in 1912. Basically, the word means that the adrenal glands are “overproducing.”
An overproduction of cortisol is what causes the typical symptoms of Cushing’s. Dogs with Cushing’s drink a lot of water and urinate a lot. Their appetite increases. They find it difficult to lose weight. Their stomachs begin to take on a pot shape as their abdominal fat increases and their abdominal muscles weaken. Their hair coat is also damaged.
Although Cushing’s can be caused by a tumor in the adrenal gland that overproduces cortisol, it is most often caused by a tumor in the pituitary gland. The pituitary gland is located in the brain, and it monitors the production of the adrenal glands. If the pituitary gland thinks the adrenals need to release more cortisol, it will send a chemical known as ACTH through the blood to the adrenal glands, which will stimulate them to release more cortisol.
A tumor in the pituitary gland means a constant overproduction of ACTH, which in turn constantly stimulates the adrenal glands to overproduce cortisol and other hormones. If Cushing’s is diagnosed, treatment involves starting the pet on a medication called Trilostane (also known by the brand name Vetoryl). It is a synthetic steroid that inhibits an enzyme in the adrenal cortex, reducing its ability to produce cortisol and, to a lesser extent, aldosterone.
Treatment of the disease is an expensive undertaking because trilostane is an expensive drug and because after initiation of treatment, follow-up blood tests are required to monitor response. Follow-up blood tests are also expensive. Testing is necessary because these hormones are so important to the body’s function that their levels must be maintained and monitored for pet health.
Untreated dogs have a shorter lifespan. They experience symptoms of exposure to high levels of steroids. These dogs develop changes in their liver and are more prone to diabetes. If they develop diabetes, it is difficult to treat. These dogs are also overweight.
If one’s pet is diagnosed with Cushing’s, the decision about treatment will be based on several factors. The pet’s age and pre-existing conditions should be taken into consideration, as well as the cost of treatment. This can be discussed with your veterinarian to create a plan that best meets your family’s needs.