Side Effects of Medicine for Cushing's Disease in Dogs

The overproduction of cortisol by the adrenal glands produces Cushing's disease (hyperadrenocorticism). Most dogs that have Cushing's disease are six years or older, according to Washington State University, though it can affect younger dogs. The disease has several side effects that vary from dog to dog, including hair loss, increased appetite, a pot-bellied appearance, increased drinking and increased urination. Other signs that are less common include weakness, walking with knuckled-over paws and panting. Cushing's is commonly treated with mitotane, a drug used for human adrenal problems.

  1. Most Common Side Effects of Mitotane

    • Dogs might show all or some of the most common side effects of mitotane. When starting treatment, watch for nausea and vomiting, loss of appetite, diarrhea, a skin rash or redness of the skin, and problems with central nervous system functions, such as lethargy, sedation, weakness and dizziness. Watch the dog closely, as vomiting and diarrhea leads to dehydration. Contact your veterinarian if vomiting and diarrhea persists, so that he can recommend a course of action to deal with dehydration and the causes of dehydration. You should also contact your veterinarian if the dog exhibits signs of dizziness or acute loss of appetite.

    Less Common Side Effects of Mitotane

    • Some dogs might also exhibit other side effects that are not seen as often but are present with mitotane treatment. These side effects are harder to see, so your dog should be tested on a regular basis to ensure he is not exhibiting high blood pressure, low blood pressure, fever, protein in the urine or bleeding of the bladder. Some of the less common side effects are evident to the lay-person, such as visual abnormalities, blood in the urine, redness of the face and skin and generalized aching. Always contact your veterinarian if you see any of these symptoms. The veterinarian might have to look at another form of treatment if the side effects of this Cushing's medicine are too severe.

    Late Side Effects of Mitotane

    • According to UNM Cancer Center, when mitotane is taken for more than two years, incidences of brain damage and function impairment might present. Function impairment becomes obvious in dogs---a dog might lose control of its bowels or bladder, or it might have a hard time walking.