Information About Cushing’s Disease In Dogs

Learn about Cushing’s disease in dogs, how to treat it, the symptoms, causes of the disease and more.

Cushing’s disease is a condition characterized by an increase in cortisone levels due to a pituitary gland tumor or enlargement of the pituitary gland. Excessive cortisone lead to various negative side effects and can make a dog ill, though these effects may also be the result of a cancer. Cushing’s disease most often occurs in older dogs and is easily mistaken for natural aging, though there are some key differences. In this article we will be explaining the causes, symptoms and treatment plans for this condition, as well as other important information.

Causes

 
Cushing’s disease is a condition characterized by heightened cortisone levels which occurs as a result of an enlargement of the pituitary gland, or tumor affecting the pituitary gland. The most common cause, is due to the presence of benign tumors, also known as microadenomas which are usually very small in size (less than 5 mm in diameter). These tumors cause an oversecretion of ACTH (corticotropin) which is responsible for an increase in the production and release of corticosteroids. Certain cancers may also lead to higher cortisone levels.

The condition may also occur as a result of over-supplementation with glucocorticoids, which may be used to control allergies, inflammation and other symptoms. While the dog’s own body is not at fault, by flooding them with corticosteroids we produce the same effects as would be caused by more conventional and natural forms of the disease.

Certain breeds are also predisposed to the condition, including terriers, beagles, poodles, sausage dogs, german shepherds, golden retrievers, labradors and boxers.

Symptoms of Cushing’s disease in dogs

 
There is a very large list of symptoms associated with Cushing’s disease in dogs. Look out for the following signs:

  • Increased hunger and thirst
  • Increased urination and incontinence
  • Pot-bellied appearance and obesity
  • Muscle weakness
  • Skin conditions (including darkening of the skin, thin skin, bruising and white scaly patches)
  • Fat build up around the neck and shoulder regions
  • Missed menstruation in females, shrunk testicles in males
  • Insomnia
  • Fatigue
  • Hair loss

In the rarest of cases, dogs may experience a condition known as pseudomyotonia.

Diagnosis

 
When diagnosing a pet for Cushing’s disease, your vet will check your dog’s cortisone levels. The methods for doing this include blood testing and urine analysis. There are two blood tests carried out for testing dogs, a dexamethasone suppression test, which tests to see if ACTH levels can be suppressed, and an ACTH stimulation test. When examining urine samples, the vet will perform a cortisol/creatinine ratio test.

When hyperadrenocorticism is diagnosed, further tests will be required to determine whether symptoms are being caused by an enlargement of the pituitary gland or by tumors. The dexamethasone suppression test may reveal tumor-based symptoms, whereas an endogenous ACTH concentration test can point to enlargement of the gland.

X-rays and ultrasound are also sometimes used to reveal tumors, though it may not always be accurate as only 50% of tumors are detectable this way.

Treatment

 
The treatment plan decided upon usually depends on the type of Cushing’s disease your dog is suffering from. When caused by tumors, the most common approach is to remove the tumor surgically. Owners who choose to go this route will often have to treat their dog with medicine such as ketoconazole for dogs prior to surgery for stability reasons. However, because surgery is quite risky, and because Cushing’s sufferers are often older, many owners decide against this approach and instead opt for non-surgical treatment.

Radiation therapy is another option, which is used in an attempt to shrink tumors which relieves pressure on the brain, minimizing neurological symptoms. This approach is often costly, and again, many owners with older dogs decide against this treatment.

In terms of medication, the most effective option currently is Lysodren for dogs, however there is a risk of side effects and can not be tolerated by all dogs, which leads to many opting to use ketoconazole or anipryl instead. Symptoms usually fade within 6 months.

Prevention

 
As stated earlier, some breeds of dog have a genetic predisposition to Cushing’s disease. Aside from this, avoiding over-use of corticosteroids can help prevent conditions such as Cushing’s from developing.



Lysodren for dogs, strong treatment for Cushing’s
Generic Cushing’s disease Wikipedia entry