Dogs with Cushing's disease can lead a normal life with medication
With symptoms like calcified skin lumps and abdominal enlargement, canine Cushing's disease sounds almost as painful for man's best friend as it does for the owner to watch. A disease with several causes (some easier to treat than others), Cushing's can occur in both canines and humans. Regardless of how many legs the afflicted walks upon, it is important to seek immediate treatment or Cushing's could result in fatal consequences.
Definition
Canine Cushing's disease, also known as hyperadrenocorticism, is the overproduction of adrenal hormone, usually corticosteroids, reports VetInfo.com. Cushing's disease can occur naturally or be brought on by an over-administration of corticosteroids such as prednisone, used to treat autoimmune diseases in dogs. The supplemented corticosteroids can be reduced and the symptoms of Cushing's disease will fade with time.
Causes
The most common cause of canine Cushing's disease is pituitary dependent hyperadrenocorticism. It accounts for 85 percent of all afflicted dogs. This occurs when the pituitary gland excretes an excess amount of the hormone ACTH. A microadenoma (benign, microscopic tumor) will normally form in the pituitary gland and produce great amounts of ACTH, which in turn causes the adrenal glands to produce large amounts of cortisol. The pituitary gland, due to the disease, is unable to respond to the high cortisol levels.
In roughly 10 percent of canine Cushing's disease sufferers, adrenal-based hyperadrenocorticism is the culprit. On one of the two adrenal glands, a tumor develops, continuing to produce cortisol even if the ACTH hormone levels drop.
Symptoms
Symptoms include increased water consumption and urination (80 to 85 percent increase), hair loss, excessive panting, thinning of skin (also known as papering), increased or insatiable appetite, abdominal enlargement, weakening of the heart and muscles, and calcinosis cutis or calcified skin lumps.
Diagnosis
Cushing's disease can be positively diagnosed by a complete blood count, urinalysis or blood chemistry panel though often don't provide a definitive diagnosis. Another diagnostic tool is the ultrasound. The low dose dexamethasone suppression test is also a commonly used test. During this test, a dog is given several low doses of dexamethasone. After eight hours, cortisol levels are tested. In a dog that has Cushing's disease, there will be no change in cortisol levels; however, a healthy dog will show an obvious decrease when tested. Over 90 percent of dogs with Cushing's disease will have no response to the dexamethasone, making this test very accurate.
Treatment
In December 2008, the FDA produced the first drug in more than 10 years to treat canine Cushing's disease. Vetoryl Capsules were the latest drug to be approved to treat canine Cushing's disease. It is the first drug approved to treat the disease in both the pituitary and adrenal glands. The medication works by stopping the production of cortisol in the adrenal glands. Common side effects included vomiting, lack of energy, diarrhea and weight loss.
The FDA reports that the naturally occurring Cushing's disease can be treated with medication but can only be cured with surgery. If the disease is in the adrenal gland and the tumor hasn't spread, the tumor should be removed. There is no surgery that can be done on the pituitary gland yet. The only other FDA-approved medication to treat canine Cushing's disease: Anipryl. It is used only to treat uncomplicated, pituitary-depended Cushing's disease.
