Cushing's Disease in Dogs: Symptoms, Diagnosis & Treatment Guide
Guide to Cushing's disease in dogs: symptoms checklist, diagnosis costs, treatment options, prognosis, and home care tips from veterinary experts.
What Is Cushing's Disease in Dogs?
Cushing's disease — medically known as hyperadrenocorticism (HAC) — occurs when a dog's body produces excessive cortisol over a sustained period. Cortisol is a steroid hormone produced by the adrenal glands (small organs sitting just above the kidneys) that regulates metabolism, immune response, and stress. When the system that controls cortisol production malfunctions, the resulting hormone overload creates a cascade of physical and metabolic changes.
According to the Merck Veterinary Manual, approximately 80-85% of Cushing's cases in dogs are pituitary-dependent (PDH), caused by a small benign tumor on the pituitary gland that over-secretes ACTH (adrenocorticotropic hormone). The remaining 15-20% are adrenal-dependent (ADH), caused by a tumor on one or both adrenal glands. A third form, iatrogenic Cushing's, results from prolonged use of corticosteroid medications like prednisone.
Cushing's disease affects roughly 1-2 dogs per 1,000 annually in the United States, making it one of the most common endocrine disorders seen in veterinary practice. It predominantly strikes middle-aged to older dogs, typically between 7 and 12 years of age, with a median diagnosis age of around 10-11 years.
Recognizing Cushing's Disease: Symptom Checklist
Cushing's disease is notoriously insidious because early symptoms develop gradually — often over months — and can easily be mistaken for normal aging. Many owners don't realize something is seriously wrong until the disease has progressed significantly. Below is a severity-organized checklist to help you identify warning signs at every stage.
| Severity Level | Symptoms | What Owners Notice |
|---|---|---|
| Early Warning Signs (0-6 months) |
|
"My dog is drinking a lot more water and needs to go out more often." Often dismissed as seasonal changes or aging. |
| Progressive Signs (6-18 months) |
|
"My dog looks pregnant but isn't gaining weight elsewhere." Hair loss is often a tipping point that brings owners to the vet. |
| Advanced / Severe Signs |
|
Neurological symptoms or sudden collapse require emergency veterinary care immediately. |
Risk Factors: Which Dogs Are Most Vulnerable?
Cushing's Disease Risk Factor Profile
- Age: Primarily 7-12 years old; rare in dogs under 6
- Sex: Females slightly more predisposed (roughly 60% of PDH cases)
- Size: PDH more common in small breeds (<20 kg / 44 lb); ADH more common in large breeds (>20 kg)
- Medication history: Prolonged corticosteroid use (prednisone, dexamethasone) for allergies, autoimmune conditions, or cancer
- Genetics: Familial predisposition suspected but not fully mapped
Certain breeds carry significantly higher risk for developing Cushing's disease. The American Kennel Club identifies the following breeds as having elevated predisposition:
| Breed | Primary Type | Notes |
|---|---|---|
| Poodle (Miniature & Standard) | PDH | Among the highest-risk breeds |
| Dachshund (all sizes) | PDH | Very commonly affected |
| Boston Terrier | PDH | Strong breed predisposition |
| Yorkshire Terrier | PDH | Small breed, higher PDH risk |
| Beagle | PDH | Moderate predisposition |
| German Shepherd | ADH | Larger breed, adrenal tumors more common |
| Labrador Retriever | ADH | Higher ADH incidence than average |
| Australian Shepherd | PDH/ADH | Elevated risk for both types |
How Vets Diagnose Cushing's Disease
Diagnosing Cushing's disease is one of the more complex endocrine workups in veterinary medicine. No single test provides a definitive answer — instead, your veterinarian will follow a multi-step diagnostic process. Here's what to expect:
Diagnostic Process Flowchart
- Step 1: Screening Blood Work ($80-$150)
Complete blood count (CBC) and chemistry panel. Vets look for elevated ALP (alkaline phosphatase), elevated ALT, high cholesterol, high blood glucose, and stress leukogram (elevated neutrophils, low lymphocytes, low eosinophils). These findings raise suspicion but do not confirm Cushing's. - Step 2: Urinalysis ($40-$80)
Dilute urine (low specific gravity, typically <1.020), possible glucose in urine, and signs of UTI. Urine cortisol:creatinine ratio (UC:CR) may be run — a normal result effectively rules OUT Cushing's. - Step 3: Low-Dose Dexamethasone Suppression Test (LDDST) ($120-$250)
The gold-standard screening test. A baseline blood cortisol sample is drawn, then a small dose of dexamethasone is injected. Blood samples are re-drawn at 4 hours and 8 hours. In a healthy dog, dexamethasone suppresses cortisol production. In a Cushing's dog, cortisol remains elevated at the 8-hour mark. This test requires 8 hours at the clinic. - Step 4: ACTH Stimulation Test ($100-$200)
Used as a complementary test or to confirm iatrogenic Cushing's. Synthetic ACTH is injected, and cortisol response is measured at 1 hour. An exaggerated cortisol response supports a Cushing's diagnosis. Note: this test only detects about 60% of PDH cases but catches ~85% of ADH cases. - Step 5: High-Dose Dexamethasone Suppression Test (HDDST) ($120-$200)
Used to differentiate PDH from ADH. In PDH, high-dose dexamethasone partially suppresses cortisol in about 60-70% of cases. ADH tumors do not respond to suppression. - Step 6: Abdominal Ultrasound ($250-$500)
Imaging the adrenal glands directly. In PDH, both adrenal glands appear normal to slightly enlarged. In ADH, one gland typically shows a mass while the other is atrophied (shrunken). Ultrasound also screens for liver enlargement and other organ changes. - Step 7 (if neurological signs present): Brain MRI ($1,500-$3,000)
If the pituitary tumor is suspected to be a macroadenoma (>10mm), or if the dog shows neurological symptoms, an MRI at a veterinary specialty center determines tumor size and treatment planning.
Total diagnostic cost range: $500-$1,200 for standard workup (Steps 1-6) at a general practice. Add $1,500-$3,000 if MRI is needed. Specialty or university teaching hospitals may charge 30-50% more than general practices.
Treatment Options for Cushing's Disease in Dogs
Can Cushing's disease be cured? The answer depends on the type. Pituitary-dependent Cushing's is generally managed (not cured) with lifelong medication. Adrenal-dependent Cushing's can sometimes be surgically cured if the tumor is benign and successfully removed. Here's a detailed comparison of available treatments:
| Treatment | Type Treated | Mechanism | Success Rate | Monthly Cost |
|---|---|---|---|---|
| Trilostane (Vetoryl®) | PDH & ADH | Inhibits 3-beta-hydroxysteroid dehydrogenase, blocking cortisol synthesis in the adrenal glands | 80-85% clinical improvement within 2-4 weeks | $50-$150/month depending on dog weight and dose |
| Mitotane (Lysodren®) | PDH & ADH | Selectively destroys the zona fasciculata and zona reticularis layers of the adrenal cortex | 70-80% clinical improvement; higher risk of adverse effects | $30-$80/month (less expensive than trilostane) |
| Adrenalectomy (surgical removal) | ADH (benign tumors) | Complete removal of affected adrenal gland; potential cure | 80-90% survival with benign tumors; malignant tumors have poor prognosis | $3,000-$7,000 one-time (surgery + hospitalization) |
| Radiation therapy | PDH (macroadenomas) | Targets and shrinks pituitary tumor, reducing ACTH secretion | Variable; improves neurological signs in 70-80% of macroadenoma cases | $3,000-$6,000 one-time course |
| Gradual steroid taper | Iatrogenic only | Slowly reducing exogenous corticosteroid dose under veterinary supervision | High — fully reversible if caught early and underlying condition allows tapering | Minimal (monitoring visits only) |
Trilostane (Vetoryl®) — The First-Line Standard
Since receiving FDA approval for canine use in 2008, trilostane has become the most widely prescribed medication for Cushing's disease. It's available in 10mg, 30mg, 60mg, and 120mg capsules. The typical starting dose is 2-6.7 mg/kg once daily, given with food to improve absorption. Most dogs show noticeable improvement in drinking and urination within 1-2 weeks, with coat and body condition changes over 3-6 months.
Critical monitoring schedule: ACTH stimulation tests are required at 10-14 days after starting trilostane, then again at 30 days, 90 days, and every 3-6 months thereafter. Each monitoring visit costs $150-$300. Skipping these follow-ups is dangerous — over-treatment can cause Addisonian crisis (acute adrenal insufficiency), which is life-threatening.
Mitotane (Lysodren®) — The Older Alternative
Mitotane was the standard treatment for decades before trilostane. It works by chemically destroying portions of the adrenal cortex. Treatment begins with a loading phase (daily dosing until symptoms improve or appetite drops, typically 5-10 days), followed by a maintenance phase (1-2 doses per week). Mitotane carries a higher risk of adverse reactions — approximately 25-30% of dogs experience vomiting, diarrhea, lethargy, or anorexia during loading. If your dog shows these signs, stop the medication and contact your vet immediately. Some owners and veterinarians prefer mitotane for cost reasons or when trilostane proves ineffective.
Prognosis and Life Expectancy
Understanding realistic outcomes helps owners make informed decisions about treatment investment and quality-of-life management.
| Scenario | Median Survival Time | Key Factors |
|---|---|---|
| PDH managed with trilostane | 2-2.5 years from diagnosis | Many dogs live 3-5+ years with consistent monitoring; some die from unrelated causes |
| PDH managed with mitotane | 2-2.2 years from diagnosis | Slightly shorter median than trilostane in some studies; higher complication risk |
| PDH with macroadenoma (>10mm) | 6-18 months (untreated); longer with radiation | Neurological progression is the primary concern; radiation can extend survival significantly |
| ADH — benign tumor, surgically removed | 18 months to 4+ years | Potentially curative; perioperative mortality is 5-10% at experienced centers |
| ADH — malignant adrenal tumor | 6-12 months | Metastasis to liver, lungs, or vena cava significantly reduces survival |
| Iatrogenic Cushing's (steroid withdrawal) | Normal life expectancy | Fully reversible if underlying condition allows complete steroid withdrawal |
| Untreated Cushing's disease | 6-24 months (highly variable) | Quality of life deteriorates; complications include diabetes, UTIs, hypertension, thromboembolism |
According to studies published in the Journal of the American Veterinary Medical Association, dogs whose Cushing's is well-managed with trilostane and who receive regular monitoring often enjoy good quality of life for years. The leading causes of death in treated Cushing's dogs are often unrelated to the disease itself — kidney failure, heart disease, and cancer are common in this older population.
Home Care and Daily Management
Living with a Cushing's dog requires consistent daily routines and vigilant monitoring. Here's what day-to-day management looks like:
Medication Administration
- Trilostane must be given with food — ideally a meal containing some fat, which significantly improves absorption. Give at the same time every day.
- Never skip doses without veterinary guidance. If you miss a dose, give it when you remember unless it's nearly time for the next one. Never double-dose.
- Keep a medication log — track dose times, appetite, water intake, and any unusual symptoms. A simple notebook or phone spreadsheet works well.
Monitoring at Home
- Track water intake: Measure daily water consumption. A Cushing's dog on effective treatment should see drinking gradually return toward normal (roughly 40-60 mL per kg per day, or about 1 oz per lb). If drinking suddenly increases again, contact your vet — dose adjustment may be needed.
- Monitor appetite: Sudden appetite loss is a red flag for over-treatment (Addisonian crisis). If your dog refuses food for more than one meal while on trilostane or mitotane, stop the medication and call your veterinarian.
- Watch for Addisonian crisis symptoms: Vomiting, diarrhea, extreme lethargy, weakness, collapse. This is a medical emergency requiring immediate veterinary intervention with IV fluids and glucocorticoid support.
- Skin and coat checks: Photograph your dog's coat condition monthly from the same angles. Hair regrowth is slow (3-6 months) but should trend positively with good cortisol control.
Lifestyle Adjustments
- More frequent bathroom breaks — even with treatment, some dogs continue to drink and urinate more than normal. Adjust walk schedules accordingly and consider doggy door access or pee pads for overnight.
- Weight management — Cushing's dogs tend to gain weight easily due to altered metabolism. Work with your vet to determine ideal caloric intake. Most Cushing's dogs benefit from a moderate-protein, moderate-fat diet. Avoid high-sodium foods, especially if hypertension is present.
- Gentle exercise — muscle wasting means your dog may not tolerate vigorous activity. Short, frequent walks are better than long hikes. Swimming is excellent low-impact exercise if your dog enjoys water.
- Minimize stress — cortisol is a stress hormone, and stressful situations can exacerbate symptoms. Keep routines predictable and avoid unnecessary environmental changes.
The Real Cost of Cushing's Disease Treatment
Cushing's disease is a significant financial commitment. Here's a realistic breakdown so you can plan accordingly:
| Expense Category | Cost Range (USD) | Frequency |
|---|---|---|
| Initial diagnostic workup (blood work, LDDST, ultrasound) | $500-$1,200 | One-time |
| Brain MRI (if macroadenoma suspected) | $1,500-$3,000 | One-time (if needed) |
| Trilostane (Vetoryl®) medication | $50-$150/month | Ongoing, lifelong |
| Mitotane (Lysodren®) medication | $30-$80/month | Ongoing, lifelong |
| ACTH stimulation monitoring tests | $150-$300 per visit | Every 3-6 months |
| Routine blood work and urinalysis | $80-$200 per visit | Every 3-6 months |
| Adrenalectomy surgery (ADH) | $3,000-$7,000 | One-time (if applicable) |
| Radiation therapy (macroadenoma) | $3,000-$6,000 | One-time course |
| Emergency Addisonian crisis treatment | $500-$2,000 | As needed (unplanned) |
Estimated first-year total cost: $1,500-$4,000 for a medically managed PDH case. Subsequent years: $1,000-$2,500 annually for medication and monitoring. Pet insurance can offset significant portions if Cushing's was not a pre-existing condition when the policy was purchased. Many comprehensive plans cover 70-90% of diagnostic and treatment costs after deductible.
When to See the Vet: Emergency Red Flags
🚨 Seek Immediate Veterinary Care If Your Dog Shows:
- Sudden collapse, extreme weakness, or inability to stand — possible Addisonian crisis or pulmonary thromboembolism
- Acute vomiting and diarrhea (especially while on trilostane or mitotane) — could indicate adrenal insufficiency
- Sudden difficulty breathing or rapid breathing at rest — possible blood clot in lungs
- Seizures, head pressing against walls, or sudden behavioral changes — possible pituitary macroadenoma expansion
- Complete refusal to eat for more than 24 hours while on Cushing's medication
- Severe lethargy — dog won't get up, won't engage, appears depressed
Stop all Cushing's medication and call your vet or emergency clinic immediately. If your regular vet is unavailable, go to the nearest emergency veterinary hospital. Bring all medication bottles with you.
For non-emergency concerns, schedule an appointment promptly if you notice:
- Gradual increase in water consumption or urination (dose may need adjustment)
- New or worsening hair loss after initial improvement
- Recurring skin infections or UTIs
- Unexplained weight gain or loss
- Changes in behavior, restlessness, or apparent discomfort
Frequently Asked Questions
Can Cushing's disease in dogs be prevented?
Unfortunately, pituitary-dependent and adrenal-dependent Cushing's disease cannot be prevented — they result from spontaneous tumor development with no known modifiable risk factors. However, iatrogenic Cushing's (caused by prolonged steroid use) can be prevented by working with your veterinarian to use the lowest effective corticosteroid dose for the shortest possible duration, and exploring steroid-sparing alternatives like cyclosporine, oclacitinib (Apoquel®), or lokivetmab (Cytopoint®) for chronic allergy management.
Is Cushing's disease painful for dogs?
Cushing's itself is not typically painful, but the secondary conditions it causes can be. Muscle weakness, skin infections, urinary tract infections, pancreatitis, and high blood pressure all create discomfort. Dogs with calcinosis cutis (calcium deposits in the skin) may experience irritation at those sites. Effective treatment of the underlying cortisol excess usually resolves or significantly improves these secondary conditions.
Can I treat my dog's Cushing's disease with natural or holistic remedies?
There is no scientific evidence that herbal supplements, melatonin, lignans, or other "natural" treatments can control Cushing's disease. While some supplements (like melatonin) may offer mild supportive benefits for coat quality, they do not address the underlying cortisol excess. Relying on unproven treatments while the disease progresses risks serious complications including diabetes, blood clots, and organ damage. Always consult your veterinarian before adding any supplement to your dog's treatment plan.
Should I put my dog down if diagnosed with Cushing's disease?
A Cushing's diagnosis alone is rarely a reason for euthanasia. Most dogs respond well to medical management and maintain good quality of life for years. Euthanasia may be considered in cases of malignant adrenal tumors with widespread metastasis, severe neurological decline from an inoperable macroadenoma, or when treatment costs are genuinely unmanageable and the dog's quality of life is declining. Discuss your individual situation honestly with your veterinarian — they can help you assess quality-of-life metrics objectively.
How often does my dog need vet visits after diagnosis?
Expect frequent visits in the first 3-6 months while medication dosing is stabilized: typically visits at 2 weeks, 4 weeks, 12 weeks, and then transitioning to every 3-6 months for life. Each monitoring visit includes an ACTH stimulation test and blood work. Consistent monitoring is non-negotiable — both under-treatment and over-treatment carry serious health risks.
Marcus Aldridge
All our authors care for dogs every day — read more of their work on the authors page.
