Cushing's Disease in the Dog

What is Cushing's Disease?

The body produces hormones through what is known as the endocrine system, and one of the common endocrine diseases in the dog is Cushing's disease. Cushing's disease is also known as hyperadrenocorticism). In this disease the adrenal glands, which are located just above the kidneys, overproduce a steroid hormone called cortisol. The hormone cortisol is essential for normal body function and responses to stress or illness, but an excess amount leads to stress and illness. There are three forms of Cushing's disease:

• .Pituitary Form. In this form of Cushing's disease there is a tumor in the pituitary gland of the brain. This tumor produces an excess amount of ACTH, a hormone that travels through the bloodstream to the adrenal glands and stimulates it to make excess cortisol. Approximately 80% of dogs with Cushing's have this form.
• Adrenal Tumor. One or both of the adrenal glands can be tumorous and overproduce cortisol. Approximately 10-15% of dogs with Cushing's have this form.
• Iatrogenic Cushing's. The source of this is steroid medication (such as prednisone or prednisolone) given to the pet for treatment of other conditions such as skin allergies.

What is the danger of having too much cortisol? Overabundance of cortisol for extended periods of time can stress the body's organs and disrupt normal metabolism, leading to harmful conditions such as diabetes, weakened immune system, pancreatitis and urinary tract infection to name a few.

Who is most susceptible to Cushing's?

Cushing's is a disease of middle-aged to older dogs. Some breeds are more prone to it; among them are miniature poodles, dachshunds, boxers, beagles and Boston terriers. It is not exclusive to these breeds and can be seen in others. Other species can also be affected with the disease.

Noticeable signs of Cushing's Disease

• frequent urination
• urinary tract infections
• increased thirst
• increased appetite
• pot-bellied, distended abdomen
• muscle wasting
• repeated skin infections, hair loss, thinning of the skin, dark spots, some dogs have calcified lesions in the skin
• panting

How is the disease diagnosed?

Your veterinarian will use a thorough history, physical examination, and testing to diagnose this disease. 

• Blood chemistry, Complete blood count, and urine analysis
• LDDS - Low-dose dexamethasone suppression test. Your veterinarian may do this test and ACTH stimulation.
• ACTH stimulation test. Your veterinarian may be necessary to do this test and LDDS.  
• urine cortisol:creatinine ratio
• Other tests may be required such as abdominal radiographs, ultrasound of the abdomen, CT scan or MRI.

Treatment

 The goal of treatment is to reduce cortisol production. Drug therapy targets the cortex (outer layer) of the adrenal gland, causing destruction of the cells which overproduce cortisol. The most common drug therapy for Cushing's is daily dosing of Vetoryl (trilostane).  Fine tuning and managing a cushingoid dog requires regular monitoring, and your veterinarian will advise you on the recommended rechecks and blood testing.

 If an adrenal tumor is present, surgery becomes an option.

At DR 4 PETS we believe a well informed pet owner is empowered to sustain their fur baby’s general health and thereby keep that beautiful human-pet bound alive. If however, father time or ill health brings your pet to the end-of-life we want to be there to help. We provide dignified and compassionate in-home euthanasia to the feline and canine population of Ventura, Oxnard, Camarillo, Santa Paula, Ojai, Thousand Oaks, Agoura, Moorpark, Simi Valley, and neighboring communities. Give us a call at (805) 494-3339.