Cushing’s Disease in Dogs: Symptoms, Diagnosis, and Treatment
Complete guide to recognizing, diagnosing, and treating Cushing's disease in dogs.
Understanding Cushing’s Disease in Dogs
Cushing’s disease is an endocrine disorder that affects dogs when their bodies produce abnormally high levels of the hormone cortisol. Normally, the adrenal glands produce cortisol in precise amounts to help regulate metabolism, immune response, and stress management. When these glands malfunction or when a pituitary tumor disrupts their regulation, cortisol levels become dangerously elevated, leading to a range of health complications. This condition, also known as hyperadrenocorticism, can significantly impact a dog’s quality of life and requires proper diagnosis and ongoing management.
Cushing’s disease is more common in middle-aged and senior dogs, particularly small breeds such as Terriers, Poodles, and Dachshunds. However, the condition can develop in dogs of any age or breed. Understanding the signs, diagnostic procedures, and available treatment options is essential for dog owners to ensure their pets receive appropriate care and support.
Symptoms of Cushing’s Disease in Dogs
Cushing’s disease presents with a variety of symptoms that can gradually develop over time. Many of these signs are related to the elevated cortisol levels affecting the dog’s metabolism, skin, and energy levels. Recognizing these symptoms early is crucial for timely veterinary intervention.
The most commonly observed symptoms include:
– Excessive panting, even without exercise or heat exposure- Increased thirst and urination frequency- Elevated appetite despite weight loss- Lethargy and reduced activity levels- Muscle weakness and general debility- Potbelly appearance with an enlarged abdomen- Hair loss and thinning of the skin- Chronic skin infections and irritation- Calcified skin lesions and bumps- Frequent urinary tract infections
The potbelly appearance is particularly characteristic of Cushing’s disease, caused by weakened abdominal muscles and redistribution of body fat. Hair loss often occurs symmetrically on the body, leaving the dog with a patchy or thin coat. Some dogs develop skin infections due to immune system suppression from excess cortisol, while others experience brittleness and fragility of the skin itself.
How Veterinarians Diagnose Cushing’s Disease in Dogs
Diagnosing Cushing’s disease requires a systematic approach combining physical examination, medical history review, and specialized diagnostic testing. Because the symptoms of Cushing’s disease can overlap with other conditions, thorough diagnostic work is essential to confirm the diagnosis accurately.
Initial Evaluation and Physical Examination
Your veterinarian will begin with a comprehensive physical examination of your dog, assessing overall health, body condition, and looking for visible signs of Cushing’s disease. During this examination, the veterinarian will inquire about your dog’s medical history, including any medications currently being taken, when symptoms first appeared, and their progression. This information helps establish a timeline and rule out iatrogenic Cushing’s disease, which can result from long-term corticosteroid therapy prescribed for other conditions.
Baseline Laboratory Testing
Before proceeding with specialized diagnostic tests, baseline laboratory work is typically performed. This includes a complete blood count (CBC) and biochemistry profile to assess overall health. Dogs with Cushing’s disease commonly show specific laboratory abnormalities, including a stress leukogram (a particular pattern in white blood cell numbers), elevated liver enzymes, particularly alkaline phosphatase (ALP), high cholesterol and triglycerides, and changes in electrolyte levels. Urinalysis is also performed to evaluate urine concentration and detect protein or other abnormalities.
Specialized Diagnostic Tests
Two main tests are used to confirm Cushing’s disease in dogs: the low-dose dexamethasone suppression test and the ACTH stimulation test. These tests are designed to evaluate how the dog’s body responds to specific hormonal challenges.
Low-Dose Dexamethasone Suppression Test (LDDS)
The low-dose dexamethasone suppression test is the preferred diagnostic method and is typically the least expensive option. The procedure begins with an initial blood draw to measure resting cortisol levels. A corticosteroid drug called dexamethasone is then administered into the dog’s muscle or vein. Additional blood samples are collected after four and eight hours to measure cortisol levels again. In healthy dogs, cortisol levels would be suppressed after eight hours due to the negative feedback mechanism. However, in dogs with Cushing’s disease, cortisol remains elevated despite the dexamethasone administration. This failure to suppress cortisol is diagnostic for the condition.
ACTH Stimulation Test
The ACTH stimulation test evaluates how the adrenal glands respond to hormonal stimulation. An initial blood sample is drawn to measure resting cortisol levels. ACTH (adrenocorticotropic hormone) is then administered into the dog’s muscle. One hour later, another blood sample is collected to measure cortisol levels. Dogs with Cushing’s disease show elevated cortisol levels in both samples, indicating that the adrenal glands are overproducing cortisol and not responding normally to hormonal regulation.
Additional Diagnostic Tests
To differentiate between pituitary-dependent and adrenal-dependent Cushing’s disease, additional tests may be performed. These include endogenous ACTH levels measurement, high-dose dexamethasone suppression test, and urine cortisol:creatinine ratio. These tests help identify the underlying cause of cortisol overproduction, which is important for determining the most appropriate treatment approach.
Imaging Studies
Imaging plays a crucial role in identifying tumors and abnormalities affecting cortisol regulation. Abdominal ultrasound is commonly used to visualize the adrenal glands and detect tumors. Computed tomography (CT) and magnetic resonance imaging (MRI) provide more detailed views of both the adrenal glands and the pituitary gland. MRI is the most effective diagnostic imaging tool for assessing the pituitary and adrenal glands; however, this testing method is considerably more expensive than ultrasound or CT scans. These imaging studies help determine whether Cushing’s disease is pituitary-dependent or adrenal-dependent, which influences treatment decisions.
Types of Cushing’s Disease
Understanding the type of Cushing’s disease your dog has is essential, as it affects treatment options and prognosis. There are three main categories of Cushing’s disease in dogs.
Pituitary-Dependent Cushing’s Disease accounts for approximately 85 percent of cases. In this form, a benign tumor develops in the pituitary gland, causing excessive production of ACTH, which stimulates the adrenal glands to produce excessive cortisol. This form is generally not curable but can be managed with lifelong medication.
Adrenal-Dependent Cushing’s Disease occurs when a tumor develops directly in one of the adrenal glands, causing it to produce excessive cortisol independently of pituitary control. This type accounts for approximately 15 percent of cases and may be treatable with surgery if the tumor has not spread and the dog is in good overall health.
Iatrogenic Cushing’s Disease develops as a side effect of prolonged corticosteroid therapy given to treat other medical conditions such as allergies, immune disorders, or inflammation. This form resolves when the corticosteroid medication is gradually discontinued, though careful management is necessary as the condition being treated may recur.
Treatment for Cushing’s Disease in Dogs
Most cases of Cushing’s disease can be managed but not cured. Treatment focuses on reducing cortisol levels and managing the signs of the disease to improve the dog’s quality of life. The appropriate treatment approach depends on the type of Cushing’s disease and the dog’s overall health status.
Medical Management
Medical treatment is the most common approach for managing Cushing’s disease, particularly for pituitary-dependent cases. Two primary medications are used to control cortisol production.
Trilostane (Vetoryl) is a steroid analogue that selectively blocks an enzyme necessary for cortisol production, thereby decreasing hormone levels. Trilostane does not damage adrenal tissue; it simply inhibits the excessive cortisol production. This is now the preferred treatment option for most veterinarians because it effectively controls symptoms while maintaining the dog’s quality of life. Dogs treated with trilostane require regular monitoring through blood tests to ensure cortisol levels remain within a therapeutic range.
Mitotane (Lysodren) is a chemotherapeutic medication that destroys part of the adrenal gland tissue so that it can no longer produce excessive cortisol. While effective, mitotane carries greater risks of side effects and requires careful monitoring. It is typically reserved for cases where trilostane is ineffective or not tolerated.
Both medications must typically be taken for the dog’s lifetime, requiring long-term commitment to daily medication administration and periodic veterinary monitoring.
Surgical Treatment
Surgical intervention is an option for select cases. Adrenal-dependent Cushing’s disease may be treated with surgical removal of the affected adrenal gland, depending on the type of tumor present, whether it has spread, and the dog’s overall health status. Surgical removal of an adrenal tumor is the only potential cure for Cushing’s disease; however, adrenal surgery carries significant risks and is performed only at specialized veterinary centers.
For pituitary-dependent Cushing’s disease, surgical removal or radiation of the pituitary tumor is theoretically possible; however, neither approach is routinely performed due to potential complications and limited availability of specialized surgeons and radiation facilities.
Dietary Management
Because dogs with Cushing’s disease generally have elevated cholesterol and triglycerides, dietary modifications play an important supportive role in treatment. A low-fat diet is typically recommended to help manage these abnormalities and support overall health. Prescription diet options specifically formulated for dogs with Cushing’s disease or gastrointestinal sensitivities are available, such as Royal Canin Gastrointestinal Adult Low Fat Diet or Hill’s Prescription Diet i/d. Your veterinarian can recommend the most appropriate diet for your individual dog’s needs.
Monitoring and Follow-Up Care
Regular monitoring is essential to assess treatment effectiveness and manage symptoms. This includes periodic physical examinations, blood tests to measure cortisol levels, and urinalysis. Your veterinarian will adjust medication dosages based on response to treatment and any side effects observed. After your dog begins treatment, contact your veterinarian if you notice changes in appetite, vomiting, diarrhea, decreased activity, or increased sleeping, as these may indicate the need for medication adjustment.
Prognosis and Long-Term Management
With appropriate treatment and regular monitoring, many dogs with Cushing’s disease can live comfortably for several years. The prognosis depends on the type of disease, the dog’s age and overall health, and how well the dog responds to treatment. Dogs with pituitary-dependent Cushing’s disease that is well-controlled with medication generally have a good outlook. Dogs with adrenal tumors that are surgically removed may have an excellent prognosis, particularly if the tumor was small and had not spread.
Dog owners play a critical role in managing their pet’s Cushing’s disease by administering medications consistently, maintaining regular veterinary appointments, observing behavioral and physical changes, and reporting concerns promptly to the veterinarian. Close communication between pet owners and veterinarians ensures optimal disease management and early detection of any complications.
Frequently Asked Questions
Q: Can Cushing’s disease in dogs be cured?
A: Most cases of Cushing’s disease cannot be cured but can be managed with lifelong medication. The only potential cure is surgical removal of an adrenal tumor in adrenal-dependent cases, but this is not always possible or recommended.
Q: How long can a dog live with Cushing’s disease?
A: With appropriate treatment and monitoring, many dogs can live several years after diagnosis. The specific lifespan depends on the dog’s age, overall health, type of Cushing’s disease, and how well the disease responds to treatment.
Q: What is the cost of treating Cushing’s disease in dogs?
A: Diagnostic testing typically costs several hundred dollars, while ongoing medication management may range from $20-100 per month depending on the dog’s size and medication chosen. Regular monitoring visits and blood tests add to the overall cost.
Q: What side effects can occur with Cushing’s disease treatment?
A: Side effects depend on the medication used. Dogs may experience changes in appetite, vomiting, diarrhea, lethargy, or weakness. Report any concerning changes to your veterinarian immediately.
Q: Is Cushing’s disease preventable in dogs?
A: Cushing’s disease cannot be prevented, as it results from spontaneous tumor development or pituitary dysfunction. However, avoiding unnecessary long-term corticosteroid use when possible can prevent iatrogenic Cushing’s disease.
References
- Cushing’s Disease in Dogs: Symptoms, Diagnosis, and Treatment — PetMD. Accessed November 2025. https://www.petmd.com/dog/conditions/endocrine/cushings-disease-in-dogs-symptoms-diagnosis
- Cushing’s Disease in Dogs — VCA Animal Hospitals. Accessed November 2025. https://vcahospitals.com/know-your-pet/cushings-disease-in-dogs
- Treating Cushing’s Disease in Dogs — U.S. Food and Drug Administration. Accessed November 2025. https://www.fda.gov/consumers/consumer-updates/treating-cushings-disease-dogs
- Cushing’s Disease in Dogs: Signs and Treatment — MedVet. Accessed November 2025. https://www.medvet.com/cushings-disease-in-dogs/
- Cushing’s Disease in dogs — PDSA (People’s Dispensary for Sick Animals). Accessed November 2025. https://www.pdsa.org.uk/pet-help-and-advice/pet-health-hub/conditions/cushing-s-disease-in-dogs
- Canine Cushing’s Disease — MSPCA-Angell. Accessed November 2025. https://www.mspca.org/angell_services/canine-cushings-disease/
Similar Articles
Read full bio of Sneha Tete
