Spotting, testing and living with Cushing’s
For some dog owners, Cushing’s is an illness they have had to deal with in their own pet. For those with no prior experience in the condition, Cushing’s is a disease associated with the adrenal glands.
The adrenal glands produce cortisol and hormones that affect the day-today functions of the body. There are two of these tiny glands. One is located at the top of each kidney. They help control metabolism and affect blood pressure, and they react to stress and even release a small amount of certain sex hormones. So, though they are small and relatively unnoticed when working normally, they cause great upheaval if they aren’t functioning properly.
Cushing’s is named after Harvey Williams Cushing, a neurosurgeon who first described the condition in humans in 1912. When we are dealing with this disease in dogs, the scientific term we use is Hyperadrenocorticism. Basically, that word means that the adrenal glands are “producing too much.”
Overproduction of the cortisol is what causes the typical symptoms of Cushing’s. Dogs with Cushing’s tend to drink a lot of water and urinate a lot. Their appetite increases. They have a hard time losing weight. They begin to have a potbelly appearance because they are gaining fat in the abdomen and their abdominal muscles are weakened. They also have a poor hair coat.
While Cushing’s can be caused by a tumor in the adrenal gland overproducing cortisol, often it is 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 bloodstream to the adrenal glands, stimulating them to release more cortisol.
A tumor in the pituitary gland means constant overproduction of ACTH, resulting in the adrenal glands getting constant stimulation to overproduce cortisol and other hormones. If Cushing’s is diagnosed, the 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 degree, aldosterone.
Treatment of the disease is an expensive undertaking because trilostane is an expensive drug and because, after starting the treatment, follow-up blood testing has to be done to monitor the response. The follow-up blood tests are expensive, too. Testing has to be done because these hormones are so important to body function that levels have to be maintained and monitored for the health of the pet.
Dogs that are not treated have a shorter life expectancy. They experience symptoms of exposure to high levels of steroids. These dogs tend to have changes to their liver and are more prone to diabetes. If they do get diabetes, it is harder to treat. These dogs also tend to be 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 preexisting conditions must be taken into account as well as the cost of treatment. This can be discussed with your veterinarian so that a plan can be put together.