Cushing's Disease in a Geriatric Dog

Cushing's disease plagues many aging dogs and can often be hard to detect.

Cushing's disease presents itself commonly in aging dogs and is characterized by the breakdown of the dog's adrenal and pituitary glands. The symptoms of Cushing's disease are vague and often confused with the effects of old age. Many treatment options are available to treat Cushing's disease symptoms.

Identification

Also known as hyperadrenocorticism, Cushing's disease is illustrated by the overproduction of glucocorticoid within the body. This disease is a complicated one due to its diverse manifestation of symptoms. The disease is often mistaken for the natural process of an aging dog. Cushing's disease is most common in dogs of middle to old age and can be caused by several different risk factors.

Causes

Normally, a dog's pituitary gland produces the hormone ACTH, which stimulates the adrenal gland to make glucocorticoid hormones. Cushing's disease results when this mechanism becomes faulty and produces excess glucocorticoid hormones. There are three main causes of Cushing's disease: medical treatment side effects, adrenal gland tumors and pituitary gland tumors. During medical treatment, a dog that receives high daily doses of cortisol over a long period of time may develop Cushing's disease. Adrenal gland tumors disrupt pituitary and adrenal gland communication, leading to excess glucocorticoid production. In addition, pituitary gland tumors cause the pituitary gland to produce extra ACTH and consequently, excess glucocorticoid hormones.

Symptoms

The symptoms of Cushing's disease show themselves in a variety of clinical signs. The most common symptoms include increased water consumption, increased urination, weight gain, excessive panting and seizures. Other clear physical changes include a pot-bellied disposition, significant hair loss, baldness and a dry coat.

Diagnosis

The diagnosis of this disorder is not always clear, due to the generality of symptoms available. Dogs suspected of having Cushing's disease should undergo a complete blood test and urinalysis to detect for abnormalities. Other screening tests that can detect Cushing's disease include finding the urine cortisol to creatinine ratio, the low dose dexamethason suppression test and the abdominal ultrasound.

Treatment

Treatment for Cushing's disease varies according to the disorder's underlying cause. For excess cortisol injections during medical treatment, a simple stoppage of cortisol will alleviate the symptoms of Cushing's disease. Surgery is available to remove benign adrenal tumors; however, removing pituitary gland tumors may be too risky. Medication such as the drug Lysodren limits the adrenal gland's ability to produce cortisol.

References

• Pet Education: Cushing's Disease
• Pet Well-Being: Dog Cushing's Disease
• The Dog Health Guide: Cushing's Disease in Dog

Resources

• Long Beach Animal Hospital