Cushing’s Disease

Our guide has been authored by qualified veterinarians, but should not be taken as substitute for medical advice or professional veterinary consultation. If your pet displays any unusual symptoms, we strongly advise seeking guidance from a veterinarian

Understanding Cushing’s Disease in dogs

Cushing’s disease, also known as hyperadrenocorticism, is a medical condition caused by excessive production of a hormone called cortisol. Cortisol is produced and stored by the adrenals, two small glands that sit on top of the kidneys. Cortisol is one of the body’s natural steroids and a normal amount of it helps the body adapt in times of stress. Cortisol also helps regulate proper body weight, tissue structure, skin condition, and other features of good health. Too much cortisol weakens the immune system, leaving the body vulnerable to other diseases and infections.

Tucker's story

Tucker, a lovable Golden Retriever, found himself at the center of concern when his owner, Phil, noticed some unusual changes in his behavior and appearance. Tucker's excessive thirst, frequent urination, and rapid weight gain prompted Phil to take him to the veterinarian for a thorough examination. After a series of tests and consultations, the veterinarian diagnosed Tucker with Cushing's Disease, a condition caused by overactive adrenal glands leading to an excess production of cortisol. This hormonal imbalance explained Tucker's symptoms and offered insights into the treatment plan ahead. With the diagnosis in hand, Phil was able to manage the disease through medication, dietary adjustments, and regular veterinary check-ups to ensure Tucker's well-being.

Cushing’s Disease's Causes: Uncovering Triggers

There are three primary causes of Cushing’s disease in dogs:

Pituitary-Dependent Cushing’s Disease (PDH): This is the most common form of Cushing’s disease in dogs, accounting for about 80-85% of cases. It occurs when there is a benign tumor in the pituitary gland, a small gland located at the base of the brain. The tumor secretes excessive amounts of adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce more cortisol.
Adrenal-Dependent Cushing’s Disease (ADH): This form of Cushing’s disease occurs when there is an adrenal tumor, either benign or malignant, present in one or both of the adrenal glands. These tumors produce excess cortisol directly, bypassing the normal regulatory mechanisms.
Iatrogenic Cushing’s disease: This form of Cushing’s disease is caused by the prolonged administration of corticosteroid medications, such as prednisone, for the treatment of various medical conditions. High doses or long-term use of these medications can suppress the normal functioning of the adrenal glands, leading to Cushing’s-like symptoms.

Recognizing Cushing’s Disease: Signs and Symptoms

Increased thirst and urination: Dogs with Cushing's disease may drink more water than usual and subsequently urinate more frequently.
Increased appetite: Affected dogs often develop a ravenous appetite and may constantly beg for food or scavenge for extra meals.
Unexplained weight gain: Dogs with Cushing's disease may experience weight gain, particularly in the abdomen, which can result in a distended or pot-bellied appearance.
Hair loss: Cushing's disease can lead to hair loss, usually starting from the trunk and progressing to the head and extremities. The skin may become thin, fragile, and prone to infections.
Muscle weakness: Dogs with Cushing's disease may exhibit muscle weakness and have difficulty performing activities they once did easily.
Increased panting: This can occur even when the weather is not warm or the dog hasn't been physically active.
Lethargy: Affected dogs may appear lethargic or have reduced energy levels.
Darkened skin: Some dogs with Cushing's disease may develop hyperpigmentation, causing the skin to become darker.
Thin skin and bruising: The skin of dogs with Cushing's disease may become thin and prone to bruising.
Susceptibility to infections: Cushing's disease weakens the immune system, making affected dogs more susceptible to various infections.

These symptoms can vary in severity depending on the underlying cause of Cushing’s disease and the duration of the condition.

Cushing’s Disease Diagnosis: How it's Identified

Veterinarians will start with medical history and a thorough physical examination. Blood Tests are also essential for diagnosing Cushing’s disease. The veterinarian may recommend a series of blood tests, including: Complete Blood Count (CBC), Biochemical Profile to evaluate organ function, including liver and kidney health, as abnormalities in these organs can be associated with Cushing’s disease. Urinalysis will help detect any urinary tract infections or changes associated with the disease while Endocrine Testing will assess cortisol levels and adrenal gland function. Imaging Techniques like abdominal ultrasound and chest radiographs are essential in some cases in order to identify the cause and location of the excessive cortisol production.

Treating Cushing’s Disease: Options and Approaches

Here are the common approaches used by veterinarians for treating Cushing’s disease in dogs:

1. Medications that suppress the production or block the effects of cortisol, the hormone responsible for the disease. The two primary medications used are:

- Lysodren: destroys or inhibits the adrenal gland’s ability to produce cortisol. It is given orally and requires careful monitoring of the dog’s cortisol levels and clinical signs.
- Trilostane: blocks an enzyme involved in cortisol production. It helps regulate cortisol levels and is often used for long-term management of the disease.

2. Dietary management: Specialized diets may be recommended to support overall health, maintain a healthy weight, and manage concurrent conditions such as diabetes or urinary tract problems.

3. Surgery: In some cases, when a tumor in the adrenal gland is responsible for Cushing’s disease, surgical removal of the tumor may be considered. This option is typically explored when the tumor is localized and non-invasive.

4. Regular monitoring: Dogs undergoing medical treatment for Cushing’s disease require regular check-ups and monitoring. This includes periodic blood tests to evaluate cortisol levels, liver function, and other relevant parameters. The veterinarian will adjust the medication dosage based on the individual dog’s response.

Cushing’s Disease: Surprising Facts

The disease is more commonly found in dogs than in cats.

While Cushing's disease is not curable, it can be effectively managed in many cases, allowing affected dogs to live a good quality of life with appropriate treatment and monitoring.

Untreated Cushing's disease can lead to complications such as diabetes mellitus, pancreatitis, urinary tract infections, muscle weakness, and an increased susceptibility to infections.

Vet's Tip: Dealing with Cushing’s Disease

Dogs with Cushing’s disease are prone to skin issues and infections. Regularly check their skin for any abnormalities, rashes, or sores. Keep their coat clean and well-groomed, and follow your veterinarian’s recommendations for skincare, including any prescribed shampoos or topical treatments.

Price Tag

Veterinary consultation

$100-$200

Bloodwork

$250-$500

Urine testing

$150-$300

Abdominal ultrasound

$300-$500

Monthly Medication

$50-$100

Latest in Research and Treatments

Recent work on somatostatin and dopaminergic receptor changes in humans and dogs with Cushing’s disease has opened the door to targeted therapy of pituitary tumors. Such therapies not only result in decreased ACTH production but a reduction in tumor size.