Cushing’s disease is a hormonal condition that most often affects middle-aged and senior dogs, and its early signs can be easy to miss. Changes such as increased thirst, appetite shifts, accidents in the house, panting, or a thinning coat tend to develop gradually, making it difficult to know whether they are part of normal ageing or something more.
The condition occurs predominantly in dogs between 7 and 12 years of age and is considered a common endocrine disorder in adult and senior dogs. Because many of its signs overlap with expected age-related changes, Cushing’s disease is often identified only after patterns begin to emerge over time. [1][2]
When questions like these arise, dogs are often referred to Boundary Bay Veterinary Specialty Hospital (BBVSH) in Surrey for a deeper evaluation. Our board-certified Internal Medicine team focuses on complex endocrine conditions like Cushing’s disease, using advanced diagnostics and thoughtful, individualised care to help dogs feel better, stay comfortable, and continue enjoying their everyday lives.
Cushing’s Disease in Dogs: An Overview
Cushing’s disease—also known as hyperadrenocorticism—occurs when a dog’s body produces excessive amounts of cortisol. Cortisol is essential for regulating metabolism, immune response, and stress, but chronically elevated levels can disrupt nearly every system in the body. [1][2]
In dogs, Cushing’s disease most commonly develops in one of two ways:
- Pituitary-dependent Cushing’s disease, caused by a (usually benign) tumour of the pituitary gland that overstimulates cortisol production. This accounts for approximately 80–85% of naturally occurring cases. [1]
- Adrenal-dependent Cushing’s disease, caused by an adrenal tumour producing excess cortisol. This accounts for approximately 15–20% of cases. [1]
Although these forms can look similar clinically, identifying the source of the disease helps guide the safest and most effective treatment plan.
Common Signs of Cushing’s Disease in Dogs
Because Cushing’s disease develops gradually, early signs are often subtle or attributed to ageing. Many families describe noticing small changes that seemed to “add up” over time. Common signs include:
- Increased thirst and urination
- Increased appetite
- Urinary accidents in the house
- Thinning hair coat or hair loss
- A pot-bellied appearance
- Reduced stamina or muscle weakness
- Stiffness or difficulty rising
Since cortisol affects multiple body systems, dogs may show a combination of hormonal, skin, and mobility-related changes. When these patterns appear together, further evaluation is often warranted.
Diagnosing Cushing’s Disease in Dogs
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 manner.
At BBVSH Surrey, this process is led by our board-certified Internal Medicine specialists, who regularly manage 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, specialised hormonal testing is used to evaluate how cortisol is being produced and regulated. Diagnostic imaging, such as abdominal ultrasound, helps assess the adrenal glands and clarify the underlying cause.
This layered approach allows the care team to confirm the diagnosis, distinguish between pituitary- and adrenal-dependent disease, and determine the safest and most appropriate treatment options—particularly important for senior dogs or those with additional medical concerns.
Treatment Approaches for Dogs with Cushing’s Disease
Once Cushing’s disease is diagnosed, treatment planning is guided by our board-certified Internal Medicine team, with recommendations tailored to each dog’s form of disease, overall health, and lifestyle.
Treatment focuses on reducing excess cortisol, improving clinical signs, and supporting long-term comfort and quality of life. While Cushing’s disease is typically chronic rather than curable, many dogs do very well with consistent management and monitoring.
Medical Treatment Options for Canine Cushing’s Disease
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 widely considered the 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- and adrenal-dependent disease. Dosing is individualised, and many dogs benefit from twice-daily administration to maintain 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 excessive cortisol suppression and 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 medication adjustments based on laboratory results and how the dog is doing at home.
Surgical and Advanced Care for Cushing’s Disease
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 tumour 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 specialised centres 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 Dogs with Cushing’s Disease Beyond Medication
Managing Cushing’s disease often involves more than hormone regulation alone. Chronic cortisol excess can contribute to muscle loss, weakness, altered posture, and reduced endurance, particularly in senior dogs.
At BBVSH Surrey, care is frequently coordinated across specialty services. In addition to oversight from our board-certified Internal Medicine specialists, dogs experiencing mobility changes may benefit from support through our Animal Rehabilitation team. Rehabilitation-focused care may include therapeutic exercise, pain-modulating modalities, and customised plans designed to support strength, balance, and comfort alongside medical treatment.
Addressing both the internal medical condition and its physical effects allows dogs not only to feel better medically, but also to move more comfortably in their daily lives.
Prognosis for Dogs Living with Cushing’s Disease
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 in daily routines
Improvement does not necessarily mean reversing age-related changes—it means helping dogs feel good where they are and supporting what matters most to them and their families.
Quality of Life for Dogs with Cushing’s Disease
A diagnosis of Cushing’s disease can feel overwhelming, especially because its signs often overlap with what many people expect from ageing. 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, rising with less stiffness, or returning to favourite activities—can be important indicators of progress. Having a veterinary team that can guide those adjustments over time helps families feel supported as needs evolve.
Cushing’s Disease in Cats: How It Differs from Dogs
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 in Dogs
What is Cushing’s disease in dogs?
Cushing’s disease is a hormonal disorder in which a dog’s body produces excess cortisol, affecting multiple body systems.
What are the early signs?
Early signs may include increased thirst and urination, appetite changes, panting, hair thinning, and reduced stamina.
Is Cushing’s disease painful?
The disease itself is not typically painful, but secondary effects can impact comfort if left untreated.
How is Cushing’s disease diagnosed?
Diagnosis involves history, physical examination, laboratory testing, hormonal assays, and imaging.
Can Cushing’s disease be cured?
Most cases are managed rather than cured, though some adrenal tumours may be surgically treated.
How long can dogs live with Cushing’s disease?
With appropriate treatment and monitoring, many dogs live comfortably for years.
Does Cushing’s disease affect mobility?
Yes. Chronic excess cortisol can contribute to muscle weakness and stiffness, particularly in senior dogs.
Do cats get Cushing’s disease?
Yes, but it is rare and presents differently than in dogs.
When should I speak with my veterinarian?
If you notice ongoing changes in your dog’s drinking, urination, appetite, coat quality, energy, or mobility, it’s worth discussing them with your veterinarian.
