Is Your Older Dog Always Looking for More Food?

STORY AT-A-GLANCE

• Cushing’s disease develops when a dog’s body is exposed to excessive cortisol, usually because of a pituitary tumor, an adrenal tumor, prolonged corticosteroid use, or, less commonly, atypical adrenal hormone overproduction
• Common signs include increased appetite, thirst, and urination, excessive panting, hair loss, thinning skin, bruising, restlessness, and a pot-bellied appearance, with symptoms often developing gradually in older dogs
• Diagnosis typically involves blood and urine testing followed by hormone tests such as the low-dose dexamethasone suppression test and ACTH stimulation test, with imaging used when needed to distinguish pituitary- from adrenal-dependent disease
• Conventional treatments include medications like trilostane (Vetoryl) and mitotane (Lysodren), both of which require careful monitoring due to side effects. Surgery and radiation are options in some cases
• Nutritional support and integrative therapies, including selected herbs, supplements, homeopathy, and acupuncture, may be used alongside veterinary care to support overall health and quality of life

A senior dog that has suddenly been eating every meal like it's their last, draining the water bowl twice a day, and needing to go outside far more often than usual may not just be getting older. When that increased appetite comes with a sagging belly and thinning coat, it could point to something deeper.

Taken one at a time, these changes are easy to dismiss. Together, however, they can be telltale signs of a condition called Cushing's disease.¹ It is one of the most common hormonal disorders in middle-aged and older dogs² and one of the most frequently missed.³

What Is Cushing's Disease?

The medical term for Cushing's disease is hyperadrenocorticism. Broken down, "hyper" means too much, "adreno" refers to the adrenal glands, and "corticism" refers to a syndrome involving the hormone cortisol. Simply put, it describes a condition in which the adrenal glands release too much cortisol into your dog's body.⁴

Cortisol is known as the fight-or-flight hormone. In a healthy dog, it is released in small amounts by the adrenal glands in response to perceived stress, triggering a release of glucose from the liver so the muscles have energy to respond. But cortisol does not just fuel the stress response. It also impacts metabolism and immune function.⁵

Cortisol production is regulated by the pituitary gland, a pea-sized structure at the base of the brain. The pituitary releases adrenocorticotropic hormone (ACTH), which signals the adrenal glands to produce cortisol. Once levels are sufficient, the pituitary reduces ACTH output, and cortisol production slows.

In dogs with Cushing's disease, this regulation fails, and cortisol continues to be produced even when the body has no need for it.⁶ Cushing's disease is most commonly seen in dogs older than 8 years, especially in breeds such as Terriers, Poodles, Dachshunds, and the American Eskimo/Spitz. It rarely occurs in cats.^7,8

Different Types of Cushing's Disease

There are a few different forms of hyperadrenocorticism, and if your pet has the disease, it is important to know which type he is dealing with.^9,10,11

• Pituitary-dependent — This is the most common form, accounting for about 80% to 85% of cases. It develops when a pituitary tumor causes excessive ACTH production.
• Adrenal-dependent — In the remaining 15% to 20% of cases, a tumor develops in an adrenal gland and triggers an upregulation of cortisol production in the body. These tumors may be benign or malignant, and treatment depends on factors such as the tumor's size, location, and whether it has spread.
• Iatrogenic — This form can develop after prolonged exposure to corticosteroid medications such as prednisone. Because these drugs act like cortisol in the body, long-term use can produce many of the same signs seen with naturally occurring Cushing's. When this form is suspected, the medication needs to be reduced gradually under veterinary supervision.
• Atypical Cushing's — This occurs when the outer or innermost layers of the adrenal glands overproduce hormones other than cortisol, most commonly aldosterone, which regulates electrolytes, or sex hormones such as estrogen and progesterone precursors. This form can produce similar outward signs, but the underlying hormone imbalance differs and may require a different diagnostic approach.¹²

Symptoms of Cushing's Disease in Dogs

The signs of Cushing's disease can vary from one dog to another, and most dogs do not develop every symptom at once. Early on, the changes may be subtle and easy to attribute to aging. As cortisol remains elevated, however, a more recognizable pattern often begins to emerge:^13,14

• Increased appetite
• Increased thirst and urination, which can lead to incontinence
• Increased panting
• Hair loss
• Abdominal weight gain (pot belly appearance), despite a reduction in calorie intake
• Thinning skin and changing of skin color (from pink to grey or black)
• Bruising
• Irritability or restlessness
• Much less commonly, rear limb weakness and blood clots

How Cushing's Disease Is Diagnosed

Diagnosing Cushing's disease can take several steps because no single test is completely accurate on its own. Your veterinarian will usually start with a physical exam, a review of your dog's symptoms and medication history, and routine blood and urine testing to look for changes that support the diagnosis.

One of the most common clues is an elevated alkaline phosphatase (ALP), a liver enzyme often elevated in dogs with excess cortisol. Cholesterol and blood sugar may also be higher than normal, while urine can become more diluted. These findings do not confirm Cushing's by themselves, but they can help determine whether additional hormone testing is warranted.¹⁵

The two tests most commonly used to evaluate Cushing's are the low-dose dexamethasone suppression test (LDDST) and the ACTH stimulation test. The LDDST looks at whether cortisol production decreases after dexamethasone (a synthetic corticosteroid) is given, while the ACTH stimulation test measures how strongly the adrenal glands respond to ACTH.¹⁶

The next step is often determining whether it is pituitary- or adrenal-dependent. A high-dose dexamethasone suppression test (HDDST) can help differentiate between the two forms. Additional blood tests, along with imaging, such as abdominal ultrasound, CT, or MRI, may be used to locate the source of excess hormone production and guide treatment.¹⁷

Treating and Managing Cushing's Disease

Once a Cushing's diagnosis is confirmed, the treatment path depends on the type and severity of the condition. Conventional options typically include drugs, surgery, or radiation, but each comes with trade-offs worth understanding before making a decision.

The two most commonly prescribed drugs are mitotane (Lysodren) and trilostane (Vetoryl). Mitotane is a chemotherapy drug used for both pituitary and adrenal Cushing's. It requires careful monitoring, as side effects can include vomiting, anorexia, neurological symptoms, low blood sugar, and depression. Dogs also need to be closely monitored for signs of hypoadrenocorticism, meaning the adrenal glands stop producing enough cortisol.¹⁸

Trilostane tends to have fewer side effects than mitotane. In some cases, the drug has caused adrenal necrosis, permanently destroying adrenal function. Other side effects may include dehydration, weakness, and electrolyte imbalances. Regular ACTH stimulation tests are needed to monitor cortisol levels throughout treatment.¹⁹

Surgery is sometimes an option. For pituitary-dependent cases, removal of the pituitary gland (hypophysectomy) can achieve remission in about 80% of dogs, though the recurrence rate is 11% and the procedure is complex. Adrenal tumors can also be surgically removed, but the death rate within one month of surgery ranges from 14% to 60%. Radiation therapy may be recommended for large pituitary tumors, though most dogs will still need medication alongside it.²⁰

Supportive Dietary Strategies and Natural Therapies

Regardless of the treatment approach, nutrition plays an important role. A fresh, whole-food diet with highly digestible protein may help preserve muscle mass, while keeping fat intake lower can be helpful when cholesterol or pancreatitis is a concern. Calcium intake may also need to be moderated in dogs that are prone to bladder stones.²¹

For dogs in the early stages or as complementary support alongside conventional treatment, Dogs Naturally Magazine highlights several natural therapies that may help, including:²²

• Herbs — Both Chinese and Western herbal traditions offer options. Chinese formulas such as Rehmannia-based preparations and Ginkgo biloba have been recommended by practitioners to help support hormone levels. Western herbs like dandelion root, burdock root, ashwagandha, and milk thistle are also used by herbalists to support stressed organs and adrenal function.
• Supplements — Glandular supplements are used by some holistic veterinarians to support adrenal function. A combination of melatonin and lignans (derived from Norwegian spruce tree hulls) has been shown to help regulate hormone levels. Studies also suggest that phosphatidylserine, derived from lecithin, may support hypothalamo-pituitary-adrenal function and help reduce cortisol levels naturally.²³
• Homeopathy — Remedies such as Arsenicum Album, Sulphur, and Hepar Sulfuris Calcareum may be prescribed based on the dog's individual symptoms. A trained homeopath will analyze the specific case before recommending a protocol.
• Acupuncture — This therapy can help regulate the endocrine system and reduce inflammation. Once a dog is stable, acupuncture sessions may only be needed every two months.

It is important to work with a veterinarian experienced in integrative or holistic medicine when pursuing natural therapies. Cushing's is a serious condition that requires professional guidance — these approaches should not be attempted without expert supervision.

Living with Cushing's Disease

Cushing's disease is a lifelong condition. If your dog has been diagnosed with it, consistent monitoring, an appropriate treatment plan, and attention to diet and lifestyle can help support a good quality of life. Because the condition can change over time, regular veterinary check-ups and periodic bloodwork are important for adjusting treatment when needed and catching complications early.

Better Health Begins in the Bowl

Better Health Begins in the Bowl

The Ultimate Pet Nutrition Guide was created to help dog and cat parents understand what truly supports lifelong health.

In this free guide, you’ll discover:

• 

  How your pet’s biology influences their nutritional needs

• 

  Why conventional feeding advice often falls short

• 

  Practical ways to choose better food for your dog or cat

Daily Retail GET THE FREE GUIDE

DOWNLOAD THE FREE GUIDE

Thank you! Please check your inbox to confirm your subscription.

Sorry, something went wrong. Please try again.

View our Privacy Policy and Terms of Service.