Mya’s owner had sensed that something was not quite right with her 12 year old spayed Bichon mix for several months, but now the dog was urinating in the house frequently and panting all night even when the temperature in the house was 60 degrees. Her thirst and appetite was becoming excessive too. She was even starting to try to steal food off the fork while her owners were sitting in front of the TV having dinner.
When I examined her she showed the classic physical traits of Cushing’s disease: a pot-bellied abdomen, hair loss along her sides, and fragile paper thin skin. We performed a series of blood and urine tests that resulted in a confirmation that Mya did in fact have Cushing’s disease. Now that we knew what we were dealing with we could consider the options available for making her more comfortable.
Cushings disease is caused from having abnormally high levels of corticosteroid hormones in the body for prolonged periods of time. Those high levels of hormones can come from one of three sources. Prednisone is a very commonly used drug that saves the lives of patients with life threatening immune system disorders and brings comfort to severely itchy allergy dogs that sometimes get no relief from anything else. It is a corticosteroid, and when given over a prolonged period of time it can cause the symptoms of cushings disease. Tapering the patient off of prednisone usually brings relief of symptoms.
More commonly the high levels of corticosteroids are being produced by the dog’s own adrenal glands where it is naturally manufactured and released in order to help the body cope with physical and emotional stress. Excessive and continuous release of corticosteroids is usually caused by a benign tumor on the pituitary gland, a pea sized area in the middle of the brain, that starts spitting out unregulated amounts of its own hormone who’s job is to tell the adrenal glands to start producing corticosteroids. The adrenal glands dutifully buckle down and do as they are told, dumping tons of unnecessary and eventually harmful corticosteroids into the body.
In rare cases the excessive corticosteroid production is caused by a tumor on the adrenal gland itself, which can often be identified with an abdominal ultrasound. Surgical removal of adrenal tumors may be a treatment option in those cases, but the surgery carries a high risk of death with it, so surgical cases must be chosen carefully.
There are four main drugs used for medical treatment. Ketoconazole and L-Deprenyl are considered less reliable for reducing symptoms, but have less potential for negative side effects. Lysodren and Trilostane are more reliable for improving symptoms, but need to be monitored carefully to prevent problems. It is important to note that survival time after diagnosis with Cushings disease is statistically the same for dogs that are treated medically and dogs that are untreated. The symptoms, however can be dramatically improved with medication, providing improved quality of life for pets and owners alike. Unfortunately there is no cure for Cushings disease, only palliation with drugs.
Information about Cushings disease in dogs, both good and bad, abounds on the internet. With a brief search I found two good articles from vetinfo.com and peteducation.com. The very first option that appeared, however, was “4 Facts Your Stupid Veterinarian Failed To Warn You About Dog Cushings Disease” offered by Michael Dole whose qualifications consist entirely of having visited more than a dozen animal shelters and having personally owned 8 dogs himself. Perhaps I am a little biased, but I recommend that you consider talking with your stupid veterinarian before embracing the unfounded claims of someone who wants to sell you untested and unproven treatments, even if he does use lots of exclamation points.