Cushing’s disease is a hormonal condition that most often affects middle-aged and senior dogs, and its signs can be easy to miss early on. Changes like increased thirst, appetite shifts, accidents in the house, panting, or a thinning coat often develop gradually, making it difficult to tell whether they’re simply part of aging or something more.
When questions like these come up, dogs are often referred to Boundary Bay Veterinary Specialty Hospital (BBVSH) for a deeper evaluation. Our board-certified Internal Medicine team focuses on complex conditions like Cushing’s disease, using advanced diagnostics and thoughtful, individualized care to help dogs feel better, stay comfortable, and continue enjoying their everyday lives.
What Is Cushing’s Disease?
Cushing’s disease occurs when a dog’s body produces too much cortisol, a hormone essential for regulating metabolism, immune response, and stress. Excess cortisol over time can disrupt nearly every system in the body.
In dogs, Cushing’s disease most commonly develops in one of two ways:
- Pituitary-dependent Cushing’s disease, caused by a (usually benign) pituitary tumor that overstimulates cortisol production. This accounts for about 80–85% of naturally occurring cases.
- Adrenal-dependent Cushing’s disease, caused by an adrenal tumor producing excess cortisol. This accounts for about 15–20% of cases.
Both forms can look similar on the surface, but identifying the source helps us recommend the safest and most effective treatment plan.
How common is Cushing’s disease in older dogs?
Cushing’s disease tends to occur predominantly in middle-aged to older dogs, often around 7–12 years of age, and is considered a common endocrine disorder in adult and senior dogs.
Common Signs Pet Owners Notice First
Cushing’s disease often develops gradually, which means the earliest signs are easy to overlook or attribute to aging. Many families tell us they noticed changes “adding up” over time. Common signs include:
- Increased thirst and urination
- Increased appetite
- Urinary accidents in the house
- Thinning hair coat or hair loss
- Pot-bellied appearance
- Reduced stamina or muscle weakness
- Stiffness or difficulty rising
Because cortisol affects multiple body systems, dogs may show a combination of hormonal, skin, and mobility-related changes. When these patterns emerge together, further evaluation is often warranted.
How Cushing’s Disease Is Diagnosed
Diagnosing Cushing’s disease requires more than a single test. Because it affects multiple body systems and develops gradually, evaluation is best approached in a stepwise, comprehensive way. At BBVSH, this process is led by our Internal Medicine team, which focuses on complex hormonal and metabolic conditions.
Diagnosis typically begins with a detailed history and physical examination, followed by baseline blood and urine testing to identify patterns consistent with excess cortisol. When indicated, specialized hormonal tests are used to evaluate how cortisol is being produced and regulated, while diagnostic imaging—such as abdominal ultrasound—helps assess the adrenal glands and clarify the underlying cause.
This layered approach allows our team to confirm the diagnosis, distinguish between pituitary- and adrenal-dependent disease, and determine the safest and most appropriate treatment options. Careful interpretation of these results is essential, particularly in senior dogs or those with additional medical concerns.
Treatment: Individualized and Long-Term
Once Cushing’s disease is diagnosed, treatment planning is guided by our Internal Medicine specialists, who tailor recommendations to each dog’s specific form of the disease, overall health, and lifestyle.
Treatment focuses on reducing excess cortisol, improving clinical signs, and supporting a dog’s comfort and quality of life over time. While Cushing’s is typically a chronic condition rather than a curable one, many dogs do very well with consistent management and monitoring.
Medical Management
For most dogs, medical therapy forms the foundation of treatment. Following are some common options – these therapies vary depending on the veterinarian and the animal being treated.
Trilostane (Vetoryl®) is currently considered the most common first-line treatment for canine Cushing’s disease. It works by inhibiting cortisol production in the adrenal glands and can be used for both pituitary-dependent and adrenal-dependent forms of the disease. Dosing is individualized, and many dogs benefit from twice-daily administration to maintain more consistent cortisol control. Ongoing blood testing is essential to ensure safe and effective regulation.
Mitotane (Lysodren®) is another medication option that reduces cortisol production by selectively destroying part of the adrenal cortex. While effective in some cases, it requires careful monitoring due to the risk of suppressing cortisol too much, and it is used less commonly today than trilostane.
Because cortisol plays an essential role in normal body function, treatment requires careful balance—lowering hormone levels enough to relieve clinical signs without causing deficiency. Regular rechecks allow the care team to adjust medication based on laboratory results and how the dog is doing at home.
Surgical and Advanced Options
In select cases, additional treatment options may be considered:
- Adrenalectomy, or surgical removal of an affected adrenal gland, may be recommended for dogs with a single adrenal tumor who are otherwise good surgical candidates. This approach can be curative but carries higher risk and requires advanced surgical expertise and postoperative care.
- Pituitary surgery or radiation therapy may be options for some dogs with pituitary-dependent disease, though availability is limited to specialized centers and not all patients are appropriate candidates.
Our internal medicine team works collaboratively across disciplines in our hospital, consulting with our board-certified surgeons to find the best options for each animal they are treating.
Supporting the Whole Dog
At BBVSH Bellingham, managing Cushing’s disease often involves collaboration across specialty services. In addition to guidance from our board-certified Internal Medicine specialists, dogs may benefit from support through our Rehabilitation Medicine team, particularly when muscle weakness, stiffness, or changes in mobility are present.
Chronic cortisol excess can contribute to muscle loss, altered posture, and reduced endurance, especially in senior dogs. Rehabilitation-focused care may include therapeutic exercises, pain-modulating modalities, and individualized plans designed to support strength, balance, and comfort alongside medical treatment.
In Lacey’s case, stabilizing the hormonal condition created an opportunity to incorporate rehabilitation therapy, helping her regain comfort, confidence, and ease of movement in her daily life.
Supporting the Whole Dog: Beyond Hormones
One important aspect of Cushing’s disease that is sometimes overlooked is its impact on muscle strength, posture, and mobility. Chronic cortisol excess can contribute to muscle wasting, weakness, and joint strain—especially in senior dogs.
This is where a multidisciplinary approach can make a meaningful difference. For patients like Lacey, stabilizing the hormonal disease opened the door to additional support through rehabilitation therapies such as:
- Therapeutic exercises to rebuild strength
- Modalities like acupuncture or laser therapy to support comfort
- Customized home exercise plans to maintain mobility
Addressing both the internal medical condition and its physical effects allows dogs not just to feel better medically, but to move more comfortably in their daily lives.
We’ve seen this in patients like Lacey, a senior Maltese–Yorkie mix whose care included internal medicine management for Cushing’s disease alongside a rehabilitation plan focused on comfort and mobility—helping her stay engaged in the routines that make life feel normal and joyful.
What Prognosis Can Look Like
Cushing’s disease is a chronic condition, but it is very often manageable. With consistent treatment and monitoring, many dogs experience:
- Improved energy levels
- Better urinary control
- Healthier skin and coat
- Increased comfort and mobility
- Renewed engagement with family life
As we saw with Lacey, improvement doesn’t always mean turning back the clock—it means helping dogs feel good where they are, and supporting what matters most to them and their families.
Living Well with Cushing’s Disease
Cushing’s disease can feel overwhelming at first, particularly because its signs often overlap with what many people expect from aging. With careful diagnosis, thoughtful treatment, and ongoing monitoring, many dogs experience meaningful improvements in comfort, energy, and daily routines.
Living with a chronic condition often means adjusting expectations rather than giving them up. Small changes—sleeping more comfortably, moving with less stiffness, or returning to favorite activities—can signal real progress. Having a veterinary team that can guide those adjustments over time helps families feel supported as needs evolve.
If you’re noticing changes in your dog and wondering whether Cushing’s disease could be part of the picture, a thorough evaluation can help bring clarity. With the right plan in place, many dogs continue to enjoy a good quality of life well into their senior years.
A Note About Cushing’s Disease in Cats
Cushing’s disease (hyperadrenocorticism) can also occur in cats, though it is considered rare and presents differently than it does in dogs. Feline cases are most often pituitary-dependent and are frequently associated with other conditions, such as diabetes mellitus. Because diagnosis and management in cats can be complex, pet owners seeking more information may find the Merck Veterinary Manual helpful: Hyperadrenocorticism in Cats
Frequently Asked Questions About Cushing’s Disease (FAQs)
What is Cushing’s disease in dogs?
Cushing’s disease, also called hyperadrenocorticism, is a hormonal disorder in which a dog’s body produces excess cortisol. Cortisol plays an important role in normal body function, but chronically elevated levels can affect many systems and lead to noticeable clinical signs. [1]
What are the early signs of Cushing’s disease in dogs?
Early signs often develop gradually and may include increased thirst and urination, increased appetite, panting, thinning hair or hair loss, a pot-bellied appearance, and decreased stamina. Because these changes can overlap with normal aging, further evaluation is often needed. [1][2]
Is Cushing’s disease painful for dogs?
Cushing’s disease itself is not typically painful, but the effects of excess cortisol—such as muscle weakness, joint strain, skin changes, and secondary infections—can reduce comfort if left untreated. With appropriate management, many dogs feel significantly better. [1]
How is Cushing’s disease diagnosed?
Diagnosis involves a combination of medical history, physical examination, blood and urine testing, specialized hormonal tests, and imaging such as abdominal ultrasound. This stepwise approach helps confirm the disease and determine whether it is pituitary- or adrenal-dependent. [1][2]
Can Cushing’s disease be cured?
Most cases of Cushing’s disease are managed rather than cured. Medical therapy can successfully control cortisol levels and clinical signs in many dogs. In select cases involving adrenal tumors, surgery may be curative, but it is not appropriate for every patient. [1][5]
What is the most common treatment for Cushing’s disease in dogs?
Medical management with trilostane (Vetoryl®) is commonly used to reduce cortisol production and control clinical signs. Treatment is individualized and requires regular monitoring to ensure safe and effective hormone regulation. [1][3]
How long can a dog live with Cushing’s disease?
With appropriate treatment and monitoring, many dogs with Cushing’s disease live comfortably for years after diagnosis. Quality of life often improves once cortisol levels are controlled and supportive care is in place. [1][2]
Does Cushing’s disease affect a dog’s mobility?
Yes, chronic excess cortisol can contribute to muscle weakness, stiffness, and reduced endurance, particularly in senior dogs. Rehabilitation-focused care may help support strength, balance, and overall comfort alongside medical treatment. [1][2]
Do cats get Cushing’s disease?
Yes, Cushing’s disease can occur in cats, but it is rare and presents differently than it does in dogs. Most feline cases are pituitary-dependent and are often associated with other conditions such as diabetes mellitus. For more information, see: Hyperadrenocorticism in Cats.
When should I talk to my veterinarian about Cushing’s disease?
If you notice ongoing changes in your dog’s drinking, urination, appetite, coat quality, energy level, or mobility, it’s worth discussing these concerns with your veterinarian. A referral for further evaluation may help clarify whether Cushing’s disease or another medical condition is involved.
Reference List
- [1] Merck Veterinary Manual – Cushing Syndrome (Hyperadrenocorticism) in Animals
https://www.merckvetmanual.com/endocrine-system/the-adrenal-glands/cushing-syndrome-hyperadrenocorticism-in-animals - [2] Merck Veterinary Manual – Disorders of the Adrenal Glands in Dogs (Dog Owner Version)
https://www.merckvetmanual.com/dog-owners/hormonal-disorders-of-dogs/disorders-of-the-adrenal-glands-in-dogs - [3] Merck Veterinary Manual – Cushing Disease (Pituitary-Dependent Hyperadrenocorticism) in Animals
https://www.merckvetmanual.com/endocrine-system/the-pituitary-gland/cushing-disease-pituitary-dependent-hyperadrenocorticism-in-animals - [4] VIN (Veterinary Information Network) – Clinical management of canine hyperadrenocorticism
https://www.vin.com/vin/ - [5] American College of Veterinary Surgeons (ACVS) – Adrenal Gland Surgery in Dogs
https://www.acvs.org/small-animal/adrenal-gland-surgery - [6] American Veterinary Medical Association (AVMA) – Endocrine diseases in pets
https://www.avma.org/resources-tools/pet-owners/petcare/endocrine-diseases-pets
