12/26/12

help a dog with Cushing’s disease

Question: My 11-year-old Dachshund, Hannah, has Cushing’s disease and the only comfort my veterinarian can offer her is radiation. I don’t believe that the quality of life my pet would have as a result of this treatment would be acceptable to me.

She drinks water by the gallon (if I don’t give it to her in an attempt to try to cut back, she sits and cries and it hurts me to see her so unhappy), so I give her the water, then she urinates anywhere she is, as long as it’s in the same room as her papers. I am constantly cleaning up wet floors and wee wee pads.


I am trying a homeopathic tablet, but it doesn’t seem to change anything. She has recently started to steal food from the cats and the other dog, and tries to steal food from my plate. (I have restricted her ability to steal from the other pets.)

Do you have any suggestions for ways I can help her?


Answer: I can sympathize with your situation with Hannah drinking and urinating too much (polyuria and polydipsia), along with excessive hunger (polyphagia). All are among the most common symptoms we see with Cushing’s disease due to an excessive amount of cortisol production from the adrenal gland(s). Other common problems include muscle weakness, hair loss, urinary or respiratory infections from a suppressed immune system, and a potbellied appearance from tremendous liver enlargement.

Cushing’s disease is usually diagnoses through hormone testing (ACTH stimulation or low dose dexamethasone suppression testing), before any treatments are administered. It is one of the most common endocrinopathies (glandular diseases) we see in older dogs. Because most of the dogs are older and often have concurrent medical conditions, the workup before treatment includes basic blood chemistry and urinalysis, chest radiographs, urine culture, abdominal ultrasound and blood pressure testing.

Pituitary dependent Cushing’s disease (PDH) is the most common form of the disease. In this form of the disease, a small tumor (microadenoma) exists in the pituitary gland. Occasionally Cushing’s disease is due to a tumor in the adrenal gland rather than the pituitary gland.

The most common treatments for Cushing’s disease are medical for PDH, and surgical for a single adrenal mass. In the rare instances of a pituitary macroadenoma, identified by MRI imaging, radiation therapy is recommended. Although it requires close monitoring, medical therapies are usually successful in controlling the symptoms of Cushing’s disease and improving the quality of life for both the patient and pet owner.

Lysodren (generically known as mitotane) has been the traditional medical therapy until recently. It directly destroys the part of the adrenal gland responsible for the production of cortisone.

I was involved in a multicenter study to test a drug called trilostane on newly diagnosed Cushing’s disease patients or patients who had not responded well to Lysodren. Trilostane — which was new at the time to the U.S., but had been used in Europe for many years — is an inhibitor of an enzyme called 3-beta-hydroxysteroid dehydrogenase. This enzyme is involved in the production of several steroid hormones, including cortisol. The FDA approved the drug in February 2009. It is marketed under the name Vetoryl. I use the trilostane almost exclusively to treat Cushing’s disease in dogs and have been extremely pleased with the results.

Although both drugs can have side effects and require frequent monitoring, most patients appear to handle trilostane better. I would consider seeking the advice of a veterinary internist as to the type of Cushing’s disease Hannah may have and the possible therapies to address it.

PDH due to a macroadenoma requiring radiation therapy would be extremely rare. I have not found holistic therapies to be of use in the management of this condition, but have been very pleased in the response of most patients to medical or surgical therapies.

Except in rare circumstances, diagnosis and treatment are not considered a medical emergency. Although fatal complications from Cushing’s disease can occur, the condition is usually a chronic one, and some patients may go for years untreated.

Best of luck with Hannah, and I hope she does well.