Hyperadrenocorticism (Cushing's Disease) in Dogs:...
Complete guide to hyperadrenocorticism (Cushing's disease) in dogs: symptoms checklist, diagnosis tests, treatment costs, prognosis, and breed risk factors.
What Is Hyperadrenocorticism (Cushing's Disease) in Dogs?
Hyperadrenocorticism, commonly known as Cushing's disease, is an endocrine disorder caused by chronic overproduction of cortisol — the body's primary stress hormone. In a healthy dog, the adrenal glands (small organs sitting atop each kidney) release cortisol in tightly regulated amounts. In a dog with Cushing's disease, that regulatory system breaks down, flooding the body with excess cortisol that damages organs over time.
According to the Merck Veterinary Manual, approximately 80–85% of cases are pituitary-dependent hyperadrenocorticism (PDH), where a small benign tumor on the pituitary gland overstimulates the adrenal glands. Roughly 15–20% of cases are adrenal-dependent (ADH), caused by a tumor on one or both adrenal glands themselves. A third form, iatrogenic Cushing's syndrome, results from prolonged use of steroid medications like prednisone.
Cushing's disease is one of the most common endocrine disorders in dogs, particularly affecting middle-aged to older animals. The Veterinary Information Network estimates it affects roughly 1–2 dogs per 1,000 annually, with certain breeds showing significantly higher predisposition. Left untreated, the disease progressively damages the liver, kidneys, and immune system, though most dogs respond well to medical management.
Recognizing the Symptoms: Early Warning Signs vs. Advanced Disease
Cortisol touches nearly every system in the body, which means Cushing's disease produces a wide constellation of symptoms that often develop gradually. Many owners don't notice changes until the disease has progressed significantly. Understanding the progression helps you catch it earlier.
| Severity | Symptom | What You'll Notice |
|---|---|---|
| Early Stage | Increased thirst (polydipsia) | Water bowl empties faster; dog lingers at faucets or toilets |
| Increased urination (polyuria) | More frequent potty breaks; accidents in previously house-trained dogs | |
| Increased appetite (polyphagia) | Begging, counter-surfing, seeming hungry even after meals | |
| Mild panting | Heavier breathing at rest, especially in cooler environments | |
| Mid Stage | Pot-bellied appearance | Abdomen distends due to fat redistribution and muscle wasting; ribs harder to feel |
| Hair loss (alopecia) | Symmetrical thinning on flanks, belly, and thighs; coat looks dull and thin | |
| Muscle weakness | Difficulty climbing stairs, jumping into car, or rising from lying position | |
| Skin changes | Thin, fragile skin; dark patches (hyperpigmentation); recurrent skin infections | |
| Advanced Stage | Calcium deposits in skin (calcinosis cutis) | Hard, gritty patches on back, neck, or groin area |
| Neurological signs | Disorientation, head pressing, circling, seizures (if pituitary tumor enlarges — macroadenoma) | |
| Recurrent infections | UTIs, skin infections, and ear infections that keep returning despite treatment | |
| Lethargy and exercise intolerance | Dog sleeps more, refuses walks, tires quickly on short outings |
One symptom pattern that catches many owners off guard is the combination of a ravenous appetite with visible muscle wasting. Your dog may seem to eat everything in sight while simultaneously losing muscle mass along the spine and limbs. This paradox is a hallmark of cortisol's catabolic effect on muscle tissue.
Breed Predisposition and Risk Factors
Who Gets Cushing's Disease?
- Age: Most commonly diagnosed in dogs aged 7–12 years; rare in dogs under 6
- Sex: Females are slightly more predisposed (approximately 60% of PDH cases)
- Weight: Dogs weighing over 44 lb (20 kg) have higher incidence of adrenal tumors
- Medication history: Prolonged corticosteroid use (prednisone, dexamethasone) for allergies, autoimmune disease, or cancer
Certain breeds carry significantly higher genetic risk for pituitary-dependent Cushing's disease. Data compiled from veterinary teaching hospitals and breed health surveys identify the following breeds as most predisposed:
- Poodles (all sizes, but Miniature and Toy Poodles show highest rates)
- Dachshunds (particularly Miniature Dachshunds)
- Boston Terriers
- Yorkshire Terriers
- Boxers (higher rate of adrenal tumors specifically)
- Australian Shepherds
- Beagles
- Cocker Spaniels
Boxers and German Shepherds show a notable predisposition to the adrenal-dependent form (ADH), which carries different treatment implications. If your dog falls into one of these breeds and is entering their senior years, proactive annual bloodwork can help catch hormonal imbalances before clinical symptoms become severe.
How Is Cushing's Disease Diagnosed?
Diagnosing Cushing's disease is one of the more complex endocrine workups in veterinary medicine. No single test provides a definitive answer — your veterinarian will use a combination of screening tests, confirmatory tests, and imaging to build a complete picture. Expect the diagnostic process to take 1–3 visits.
Typical Diagnostic Sequence
- Baseline blood panel and urinalysis — Your vet checks for elevated alkaline phosphatase (ALP), elevated cholesterol, dilute urine, and possible UTI. Cost: $150–$300.
- Urine cortisol:creatinine ratio (UCCR) — A home-collected morning urine sample screens for excess cortisol excretion. This is a sensitive but non-specific test: a normal result effectively rules out Cushing's, but an elevated result requires further testing. Cost: $50–$100.
- Low-dose dexamethasone suppression test (LDDST) — The gold-standard confirmatory test. Your dog receives a small dexamethasone injection, and blood is drawn at 4 and 8 hours to see if cortisol suppresses normally. In a healthy dog, it suppresses. In a Cushing's dog, it doesn't. This test requires 8 hours at the clinic. Cost: $200–$400.
- ACTH stimulation test — Measures adrenal reserve by injecting synthetic ACTH and measuring cortisol response. Better at identifying iatrogenic Cushing's and adrenal tumors, but misses about 20% of PDH cases. Cost: $200–$350 (synthetic ACTH prices have risen significantly).
- High-dose dexamethasone suppression test (HDDST) — If LDDST confirms Cushing's, this test helps differentiate PDH from ADH. Higher dexamethasone doses will suppress cortisol in most PDH dogs but not ADH dogs. Cost: $200–$350.
- Abdominal ultrasound — Visualizes the adrenal glands directly. Enlarged symmetrical glands suggest PDH; one enlarged and one atrophied gland suggests ADH. Also screens for liver changes. Cost: $300–$600.
- Endogenous ACTH level — A blood test that measures the dog's own ACTH production. High levels indicate PDH; low levels indicate ADH. Cost: $100–$200 (often sent to a reference lab).
Total diagnostic costs for a full Cushing's workup typically range from $900 to $2,500, depending on your region, whether your clinic runs tests in-house or sends them to a reference laboratory (like Idexx or Antech), and whether you see a general practitioner or a veterinary internal medicine specialist.
According to the American Kennel Club's veterinary advisors, some dogs present with "atypical Cushing's disease" where standard tests return borderline or conflicting results. In these cases, your vet may recommend repeating tests in 3–6 months, measuring sex hormone panels, or referring to a board-certified veterinary internist for advanced diagnostics.
Treatment Options: Medical, Surgical, and Supportive
Once your veterinarian has confirmed the diagnosis and determined whether the disease is pituitary-dependent or adrenal-dependent, treatment planning begins. The approach differs significantly between the two forms.
| Treatment | Used For | How It Works | Success Rate | Ongoing Cost |
|---|---|---|---|---|
| Trilostane (Vetoryl®) | PDH and ADH | Inhibits cortisol synthesis in adrenal glands; given once or twice daily with food | 75–85% show clinical improvement within 2–4 weeks | $40–$120/month depending on dog size and dose |
| Mitotane (Lysodren®) | PDH (less commonly used now) | Selectively destroys the cortisol-producing layer of the adrenal cortex; requires careful loading phase | 70–80% response rate; higher risk of adrenal insufficiency | $30–$80/month |
| Adrenalectomy (surgery) | ADH (benign adrenal tumor) | Surgical removal of the affected adrenal gland; performed by a board-certified surgeon | Curative in ~80% of benign ADH cases if no metastasis | $3,000–$7,000 one-time (surgery + hospitalization) |
| Radiation therapy | PDH with macroadenoma (large pituitary tumor) | Targets and shrinks the pituitary tumor over 3–5 weeks of treatments | 50–75% improvement in neurological signs; does not always normalize cortisol | $4,000–$8,000 one-time |
| Supportive care only | Mild cases or dogs with significant comorbidities | Managing secondary infections, dietary adjustments, and monitoring without cortisol-lowering drugs | Does not halt disease progression; symptom management only | $50–$150/month (antibiotics, supplements, monitoring) |
Trilostane (Vetoryl®) is the current first-line treatment for most cases of Cushing's disease and is the only FDA-approved medication for this condition in dogs. It works by inhibiting the enzyme 3-beta-hydroxysteroid dehydrogenase, which blocks cortisol production. Your vet will start at a conservative dose based on your dog's weight and adjust upward based on follow-up ACTH stimulation tests.
The monitoring schedule for trilostane is critical: your dog will need an ACTH stimulation test at approximately 10–14 days after starting, then again at 30 days, 90 days, and every 3–6 months thereafter. Skipping these monitoring appointments risks either undertreating (disease progresses) or overtreating (Addisonian crisis — a life-threatening drop in cortisol). Each monitoring visit with ACTH stim typically costs $200–$400.
Prognosis and Life Expectancy
The prognosis for Cushing's disease varies considerably depending on the form, the presence of complications, and how early treatment begins.
| Scenario | Median Survival Time | Key Factors |
|---|---|---|
| PDH, well-managed with trilostane | 2–2.5 years (many live 3–5+ years) | Consistent medication, regular monitoring, no macroadenoma |
| PDH with pituitary macroadenoma (>10mm) | 6–18 months | Tumor may cause neurological signs; radiation may extend survival |
| ADH, benign tumor, surgically removed | Potentially curative; normal lifespan | Surgical complication rate ~10–15%; post-op hormone replacement needed temporarily |
| ADH, malignant adrenal carcinoma | 6–12 months | Tumor invasion into vena cava or metastasis worsens prognosis |
| Iatrogenic (medication-induced) | Often reversible with gradual steroid taper | Must taper slowly under veterinary supervision; never stop steroids abruptly |
| Untreated Cushing's disease | 6–24 months depending on complications | Death usually from diabetes, kidney failure, pancreatitis, or pulmonary thromboembolism |
These survival figures come from retrospective studies published in the Journal of Veterinary Internal Medicine and the Journal of Small Animal Practice. It's important to understand that median survival means half of dogs live longer than that number — many well-managed Cushing's dogs live 4–6 years after diagnosis and ultimately pass away from unrelated causes.
Dogs that develop concurrent diabetes mellitus (which occurs in roughly 10–15% of Cushing's cases) or pulmonary thromboembolism face more complex management and generally shorter survival times. Your veterinarian will screen for these comorbidities during the initial workup.
Home Care and Daily Management
Managing a dog with Cushing's disease at home is very doable, but it requires consistent routines and attentive observation. Here's what daily life looks like:
Medication Administration
Trilostane must be given with food for proper absorption. Most veterinarians now recommend twice-daily dosing (every 12 hours) rather than once daily, as studies show this provides more stable cortisol control with fewer side effects. Set a phone alarm — consistency matters. If you miss a dose, give it when you remember unless it's close to the next scheduled dose. Never double up.
Water and Bathroom Access
Even with treatment, your dog will likely drink and urinate more than a healthy dog. Ensure constant access to fresh water — never restrict water intake for a Cushing's dog. Provide more frequent potty breaks or consider a doggy door. Some owners use indoor potty systems or pee pads overnight for senior dogs with limited mobility.
Nutrition
Feed a high-quality, complete-and-balanced diet with moderate fat content (look for AAFCO statement and 15–25% fat on the guaranteed analysis). Avoid high-sodium treats, as Cushing's dogs are prone to hypertension. If your dog has concurrent pancreatitis (a common comorbidity), your vet may recommend a low-fat prescription diet like Hill's i/d or Royal Canin GI Low Fat.
Skin and Coat Care
The thin, fragile skin of a Cushing's dog needs protection. Avoid rough play that could cause skin tears. Use a soft-bristle brush rather than metal grooming tools. If calcinosis cutis lesions develop, your vet may prescribe topical dimethyl sulfoxide (DMSO) gel to help dissolve calcium deposits. Bathe with gentle, oatmeal-based shampoos to reduce secondary bacterial or yeast infections.
Monitoring at Home
Keep a simple daily log tracking:
- Water consumption (measure how many cups per day — a rough guideline is that normal intake is approximately 1 ounce per pound of body weight per day; Cushing's dogs often drink 2–4 times that)
- Appetite level (1–5 scale)
- Energy and activity level
- Any vomiting, diarrhea, or unusual behavior
This log becomes invaluable at recheck appointments, helping your vet assess whether the current dose is effective.
The Real Cost of Cushing's Disease Treatment
Budgeting for Cushing's disease requires planning for both the initial diagnostic phase and ongoing lifetime management. Here's a realistic breakdown based on 2025–2026 U.S. veterinary pricing data:
| Expense Category | Low Estimate | High Estimate | Frequency |
|---|---|---|---|
| Initial diagnostic workup (full panel) | $900 | $2,500 | One-time |
| Abdominal ultrasound | $300 | $600 | One-time (may repeat annually) |
| Trilostane (Vetoryl®) medication | $480/year | $1,440/year | Ongoing monthly |
| ACTH stim monitoring visits | $600/year | $1,600/year | 2–4 times per year |
| Secondary infection treatments (UTIs, skin) | $100/year | $500/year | As needed |
| Adrenalectomy (if ADH) | $3,000 | $7,000 | One-time |
| Estimated first-year total (PDH, medical management) | $2,500 | $6,500 | Year one |
| Estimated annual ongoing cost (years 2+) | $1,200 | $3,500 | Per year |
Pet insurance can significantly offset these costs if you enroll your dog before diagnosis. Most comprehensive plans (Trupanion, Healthy Paws, Nationwide) cover Cushing's disease treatment including medications and monitoring, minus your deductible and co-pay. However, if your dog has already been diagnosed, it will be considered a pre-existing condition and excluded from coverage. This is one of the strongest arguments for enrolling in pet insurance during your dog's healthy years.
When to See the Vet Immediately
🚨 Emergency Red Flags — Call Your Vet or Emergency Clinic Now
- Acute vomiting and diarrhea while on trilostane or mitotane — could indicate Addisonian crisis
- Collapse, extreme weakness, or inability to stand — possible adrenal crisis or pulmonary thromboembolism
- Sudden disorientation, head pressing, circling, or seizures — may indicate pituitary macroadenoma expansion
- Rapid, labored breathing or blue-tinged gums — possible pulmonary blood clot (thromboembolism)
- Severe lethargy with refusal to eat for 24+ hours while on Cushing's medication
ASPCA Animal Poison Control: (888) 426-4435 (available 24/7, consultation fee applies) — call if your dog accidentally ingests a large quantity of medication or another animal's steroid medication.
For non-emergency concerns — like a slight increase in thirst or a new patch of hair loss — schedule a regular appointment within 1–2 weeks. These are important developments to discuss with your vet but do not require an emergency visit.
Prevention and Early Detection
Pituitary-dependent Cushing's disease cannot be prevented — it arises from spontaneous benign tumors with no known environmental trigger. However, you can take steps to reduce risk and catch the disease early:
- Minimize unnecessary steroid use. If your dog is prescribed prednisone for allergies or inflammation, ask your vet about steroid-sparing alternatives (Apoquel, Cytopoint, immunotherapy). When steroids are necessary, use the lowest effective dose for the shortest duration.
- Annual senior bloodwork after age 7. A baseline chemistry panel and urinalysis can catch early cortisol-related changes (rising ALP, dilute urine) before obvious symptoms appear. Cost: $100–$200 annually.
- Track water consumption. If you notice your dog's water intake creeping up over several weeks — especially if they're over 7 years old and in a predisposed breed — mention it at your next visit even if everything else seems fine.
- Maintain a healthy weight. While obesity doesn't cause Cushing's, it complicates diagnosis (many symptoms overlap) and treatment, and increases the risk of concurrent diabetes.
Frequently Asked Questions
Can Cushing's disease in dogs be cured?
Adrenal-dependent Cushing's disease caused by a benign adrenal tumor can potentially be cured through surgical removal of the affected gland (adrenalectomy), with an approximately 80% success rate when the tumor hasn't metastasized. Pituitary-dependent Cushing's disease, which accounts for 80–85% of cases, cannot be cured but can be effectively managed with daily medication for the rest of the dog's life. Many dogs live 2–5+ years with good quality of life on trilostane.
Is Cushing's disease painful for dogs?
Cushing's disease itself is not acutely painful in the way an injury or infection might be. However, the secondary effects can cause significant discomfort: muscle weakness makes movement difficult, skin infections cause itching and irritation, calcinosis cutis lesions can be tender, and the constant hunger creates a state of perpetual restlessness. Effective treatment usually resolves these discomforts within weeks.
What happens if Cushing's disease is left untreated?
Untreated Cushing's disease progressively damages multiple body systems. Excess cortisol suppresses the immune system (leading to recurrent infections), promotes insulin resistance (leading to diabetes in 10–15% of cases), causes progressive muscle wasting, weakens bones, and increases the risk of blood clots in the lungs (pulmonary thromboembolism), which can be fatal. Median survival for untreated dogs is estimated at 6–24 months depending on complications.
Can I give my dog melatonin or lignans for Cushing's disease?
Some holistic veterinarians recommend melatonin (3–9 mg per day depending on size) and flaxseed lignans as adjunctive supplements for Cushing's disease, based on limited research suggesting they may mildly inhibit cortisol production enzymes. These are not replacements for trilostane or mitotane and should only be used alongside conventional treatment under your veterinarian's supervision. Evidence for their efficacy remains preliminary — discuss with your vet before adding supplements.
How quickly will my dog improve after starting treatment?
Most owners notice reduced drinking and urination within 1–3 weeks of starting trilostane at an effective dose. Appetite normalizes within 2–4 weeks. Hair regrowth is the slowest improvement — coat changes take 3–6 months to become visible, and some dogs never fully regrow their original coat. Muscle strength improves gradually over 2–4 months with regular gentle exercise.
Which breeds are most prone to Cushing's disease?
Poodles (especially Miniature and Toy), Dachshunds, Boston Terriers, Yorkshire Terriers, Boxers, Australian Shepherds, Beagles, and Cocker Spaniels show the highest breed predisposition. Boxers and German Shepherds have a noted predisposition to the adrenal tumor form specifically. Females are slightly more commonly affected than males, and most cases occur in dogs aged 7–12 years.
Should I see a specialist for my dog's Cushing's disease?
Most general practice veterinarians are comfortable managing straightforward pituitary-dependent Cushing's disease. Consider referral to a board-certified veterinary internist (DACVIM) if: your dog's tests give conflicting results, your dog has a pituitary macroadenoma with neurological signs, your dog has an adrenal tumor and you want to explore surgery, or your dog isn't responding to standard treatment protocols. Specialist consultations typically cost $200–$400 for the initial visit.
This article is intended for educational purposes and does not replace professional veterinary advice. Always consult your veterinarian for diagnosis and treatment of your dog's specific condition. Treatment decisions should be made in partnership with a licensed veterinarian who has examined your dog and reviewed their full medical history.
Jonas Cole
All our authors care for dogs every day — read more of their work on the authors page.
