Cushing's syndrome ("hyperadrenocorticism") is a chronically debilitating hormone imbalance that can affect many species, humans included. We will limit our discussion to dogs and cats, however. Cushing's syndrome, also called Cushing's disease, results from excessive cortisol in the bloodstream and the symptoms all stem from long term over-exposure to this hormone.
There are many clinical signs associated with Cushing’s syndrome in the dog. These signs usually come on very gradually and, because of this slow onset, these changes are often written off as part of the normal aging process. The following is a list of common symptoms which an owner might observe in their pet at home.
Owners often notice that lately the water bowl must be filled more frequently than in the past. Some dogs are unable to hold their bladder all night and begin crying to go outside during the night when previously this was unnecessary.
Also, urinary tract infections may also be detected and true urine leaking may be observed.
Each day a dog should drink about one cup of water for each ten pounds of body weight, though this can vary somewhat with environmental temperature and activity level. Dogs that truly have excessive water consumption will consume vastly more than this regularly.
This symptom often leads dogs to beg incessantly or steal food from the garbage. It is important for an owner not to be fooled by the pet’s “good appetite;” eating well is not necessarily a sign of normal health.
This symptom, present in over 90% of Cushing’s syndrome dogs, results from hormonal redistribution of body fat plus a breakdown of abdominal musculature.
Muscle protein is broken down in Cushing’s syndrome. The result may be seen as exercise intolerance, lethargy, or reluctance to jump up on furniture or climb stairs.
The classical signs of endocrine (hormonal) skin diseases are:
- Hair loss on the main body sparing the head and legs
- Thin, wrinkled skin with poor wound healing
- Hair that does not grow back after clipping.
- Blackheads and darkening of the skin, especially on the abdomen.
- Persistent or recurring skin infections (especially if the dog is not itchy during times when the skin infection is cleared).
Another condition of the skin which may be observed is called Calcinosis Cutis, in which calcium deposits occur within the skin. These are raised, hard, almost rock-like areas which can occur almost anywhere on the body.
Some other notable findings might include: excessive panting and shortness of breath, infertility, extreme muscle stiffness (called “pseudomyotonia” - a very very rare symptom in Cushing’s disease), and high blood pressure.
Aside from the symptoms described above, advanced untreated Cushing's disease puts a dog at risk for the following serious problems:
In the cat, the clinical features of Cushing’s disease are similar to those in the dog: excess water consumption, muscle wasting, pot-bellied appearance, thin coat, and skin abnormalities. Some cats develop a peculiar curling-in of their ear tips. An important difference to note is that while only 10% of dogs with Cushing’s disease develop diabetes mellitus, 80% of cats with Cushing’s disease develop diabetes mellitus. Diabetes in an animal with Cushing’s disease is very difficult to control until the Cushing’s disease is controlled.
For more information on Diabetes mellitus in cats, click here.
Page last updated: 11/18/2012