Complete 2026 Guide to Diagnosis
Guide to treatment for Cushing's in dogs covering diagnosis costs, medication options, surgery outcomes, life expectancy, and daily management tips.
What Is Cushing's Disease in Dogs?
Cushing's disease — medically known as hyperadrenocorticism (HAC) — is an endocrine disorder caused by chronic overproduction of cortisol, the body's primary stress hormone. In a healthy dog, the pituitary gland signals the adrenal glands (located near the kidneys) to release cortisol in carefully regulated amounts. Cushing's disease disrupts this feedback loop, flooding the body with excess cortisol that damages organs, suppresses immunity, and alters metabolism over months to years.
There are two primary forms. Pituitary-dependent hyperadrenocorticism (PDH) accounts for approximately 80–85% of cases and is caused by a benign tumor on the pituitary gland that continuously secretes adrenocorticotropic hormone (ACTH). Adrenal-dependent hyperadrenocorticism (ADH) represents about 15–20% of cases and results from a tumor on one or both adrenal glands. A third, often-overlooked form called iatrogenic Cushing's develops when dogs receive prolonged corticosteroid medications (prednisone, dexamethasone) for allergies, arthritis, or autoimmune conditions.
According to the Merck Veterinary Manual, Cushing's disease is one of the most commonly diagnosed endocrine disorders in middle-aged and older dogs, with an estimated incidence of 1–2 cases per 1,000 dogs annually. Without treatment, progressive cortisol elevation leads to diabetes, hypertension, kidney failure, recurrent infections, and significantly shortened lifespan.
Recognizing the Symptoms of Cushing's Disease
Cushing's disease is notoriously insidious because early symptoms mimic normal aging. Many owners don't seek veterinary attention until the disease has progressed significantly. The following checklist organizes symptoms by severity to help you identify when your dog may need evaluation.
| Severity | Symptom | What You'll Notice |
|---|---|---|
| Early Warning Signs | Increased thirst (polydipsia) | Drinking noticeably more water; emptying bowls faster than usual |
| Increased urination (polyuria) | More frequent potty breaks, indoor accidents in a previously house-trained dog | |
| Increased appetite (polyphagia) | Begging more intensely, scavenging, seeming ravenously hungry even after meals | |
| Mild hair thinning | Coat losing luster, thinning along the trunk while head and legs remain normal | |
| Slight weight gain | Gradual abdominal enlargement that owners often attribute to overeating | |
| Moderate / Progressing Signs | "Pot-bellied" appearance | Distinctive rounded, distended abdomen from muscle wasting and fat redistribution |
| Bilateral hair loss (alopecia) | Symmetrical hair loss on flanks, trunk, and tail; skin may darken (hyperpigmentation) | |
| Muscle weakness | Difficulty climbing stairs, reluctance to jump, visible muscle wasting along the spine | |
| Recurrent skin infections | Frequent bacterial or yeast skin infections that don't fully resolve with treatment | |
| Panting excessively | Heavy breathing at rest, not associated with exercise or heat | |
| Advanced / Severe Signs | Calcium deposits in skin (calcinosis cutis) | Hard, gritty, plaque-like patches on the back, neck, or groin |
| Neurological signs | Disorientation, head pressing, circling, seizures (from macrotumor pressing on brain) | |
| Blood clots (thromboembolism) | Sudden hind-leg paralysis, acute respiratory distress, collapse | |
| Diabetes mellitus (secondary) | Extreme thirst/urination with weight loss; complicates Cushing's management significantly | |
| Hypertension | Elevated blood pressure detectable at vet; may cause retinal damage or nosebleeds |
🚨 When to See the Vet Immediately
Seek emergency veterinary care if your dog exhibits any of these red-flag symptoms:
- Sudden collapse or inability to stand — may indicate a pulmonary thromboembolism (blood clot in the lungs)
- Seizures or severe disorientation — suggests a pituitary macrotumor (tumor >10mm) compressing brain tissue
- Acute hind-leg paralysis — possible aortic saddle thrombus, a life-threatening emergency
- Rapid, labored breathing at rest — could signal congestive heart failure secondary to hypertension
- Vomiting blood or black tarry stools — cortisol-induced gastrointestinal ulceration
For non-emergency concerns like increased thirst and hair thinning, schedule a routine appointment within 1–2 weeks. Early diagnosis dramatically improves long-term outcomes.
Risk Factors: Which Dogs Are Most Prone to Cushing's Disease?
Key Risk Factors
- Age: Most commonly diagnosed in dogs aged 7–12 years; rare in dogs under 6
- Sex: Females are slightly more predisposed than males (approximately 60:40 ratio)
- Size: Small-to-medium breeds are disproportionately affected by PDH; large breeds more commonly develop adrenal tumors
- Medication history: Dogs on long-term corticosteroids for allergies, ear infections, or autoimmune disease are at high risk for iatrogenic Cushing's
- Genetics: Familial predisposition documented in several breeds, though no definitive genetic marker has been identified
Certain breeds show significantly higher incidence rates. According to data compiled by the American Kennel Club and veterinary endocrinology literature, the following breeds are most commonly affected:
| Breed | Primary Form | Notes |
|---|---|---|
| Poodle (Miniature & Standard) | PDH | One of the highest-risk breeds; strong familial clustering |
| Dachshund | PDH | Pot-bellied appearance may be mistaken for breed conformation |
| Small Terriers (Yorkshire, Boston, Jack Russell) | PDH | Often present with pronounced skin changes |
| Beagle | PDH | Higher-than-average incidence in research colony data |
| German Shepherd | ADH | Adrenal tumors more common in larger breeds |
| Australian Shepherd | ADH/PDH | Reported predisposition to both forms |
How Is Cushing's Disease Diagnosed in Dogs?
Diagnosing Cushing's disease is one of the more complex workups in veterinary endocrinology. No single test provides a definitive answer — your veterinarian will use a multi-step diagnostic protocol that progressively narrows down the diagnosis. Here's what to expect:
Diagnostic Process Flowchart
- Step 1 — Initial Screening Blood Work & Urinalysis
Your vet runs a complete blood count (CBC), serum biochemistry panel, and urinalysis. Classic findings include elevated alkaline phosphatase (ALP), elevated ALT, dilute urine (low specific gravity <1.020), and possible urinary tract infection. Estimated cost: $150–$300 - Step 2 — Confirmatory Hormone Testing
If screening results are suspicious, your vet orders one or both definitive tests:- Low-dose dexamethasone suppression test (LDDST): Blood is drawn, a small dose of dexamethasone is injected, and blood is rechecked at 4 and 8 hours. In healthy dogs, dexamethasone suppresses cortisol production; in Cushing's dogs, cortisol remains elevated. This is considered the gold-standard screening test. Estimated cost: $200–$350
- ACTH stimulation test: Blood is drawn before and 1 hour after an injection of synthetic ACTH. An exaggerated cortisol response confirms hyperactive adrenal glands. This test is also used to monitor treatment response. Estimated cost: $200–$350
- Urine cortisol:creatinine ratio (UCCR): A non-invasive at-home urine collection that can rule OUT Cushing's if results are normal, but cannot confirm it if elevated. Estimated cost: $50–$100
- Step 3 — Differentiating PDH from ADH
Once Cushing's is confirmed, your vet needs to determine which form:- High-dose dexamethasone suppression test (HDDST): A higher dose of dexamethasone suppresses cortisol in PDH dogs (the pituitary tumor still partially responds to feedback) but not in ADH dogs. Estimated cost: $200–$350
- Endogenous ACTH levels: Blood test measuring natural ACTH — high in PDH (pituitary overproducing), low in ADH (adrenal tumor suppresses pituitary). Requires special sample handling. Estimated cost: $100–$200
- Step 4 — Imaging
- Abdominal ultrasound: Evaluates adrenal gland size and shape. Symmetrically enlarged adrenals suggest PDH; one enlarged and one atrophied adrenal suggests ADH. Also screens for concurrent liver disease, bladder stones, and other abdominal pathology. Estimated cost: $300–$600
- CT or MRI of the brain: Recommended if neurological symptoms are present or if a pituitary macrotumor (>10mm) is suspected. Essential pre-surgical planning for hypophysectomy. Estimated cost: $1,500–$3,000
Total diagnostic cost range: Most owners spend between $600 and $1,500 for a complete Cushing's workup (Steps 1–3 plus abdominal ultrasound). Add $1,500–$3,000 if advanced brain imaging is needed.
Treatment Options for Cushing's in Dogs
The treatment for Cushing's in dogs depends on which form your dog has, the severity of symptoms, tumor size, your dog's overall health, and your budget. Here's a detailed comparison of the primary treatment approaches:
| Treatment | Best For | Success Rate | Key Risks | Cost Range |
|---|---|---|---|---|
| Trilostane (Vetoryl®) | PDH and ADH; first-line medical therapy | 75–85% symptom improvement | Adrenal insufficiency (Addisonian crisis) if overdosed; GI upset; rare fatal reactions | $40–$120/month (dose-dependent) |
| Mitotane (Lysodren®) | PDH; older protocol, used less frequently since trilostane approval | 70–80% response rate | Deliberately destroys adrenal cortex tissue; higher risk of permanent Addison's disease; requires careful loading phase | $25–$60/month |
| Adrenalectomy (surgical removal) | ADH with benign, unilateral adrenal tumor | Curative in 75–90% of benign ADH cases | Surgical complications (hemorrhage, pancreatitis); perioperative mortality 5–10%; requires experienced surgeon | $3,000–$6,000 (one-time) |
| Hypophysectomy (pituitary surgery) | PDH, especially with macrotumor; limited availability | 70–85% remission; few centers offer this | Highly specialized procedure; diabetes insipidus post-op; requires travel to specialty center | $5,000–$10,000+ |
| Radiation therapy | Pituitary macrotumors causing neurological signs | 60–80% reduction in tumor size; symptom improvement | Does not normalize cortisol (still need trilostane); requires multiple sessions under anesthesia | $4,000–$8,000 (full course) |
| Supportive / monitoring only | Mild cases in very elderly dogs where treatment risks outweigh benefits | N/A — manages symptoms only | Disease progression; secondary diabetes, infections, hypertension | $50–$150/monitoring visits |
Trilostane (Vetoryl®) — The Gold Standard Medical Treatment
FDA-approved for canine Cushing's disease in 2008, trilostane works by inhibiting 3β-hydroxysteroid dehydrogenase, an enzyme essential for cortisol synthesis in the adrenal glands. It doesn't cure the underlying tumor but effectively manages cortisol levels.
Dosing protocol: Trilostane is typically started at 1–2 mg/kg once daily with food. Some dogs require twice-daily dosing for adequate 24-hour cortisol control. Your veterinarian will recheck an ACTH stimulation test at 10–14 days, 30 days, and 90 days after starting treatment, then every 3–6 months for life. Dose adjustments are common — approximately 40% of dogs need at least one dose increase within the first year.
Brand vs. generic: Dechra's Vetoryl® is the brand-name product. Generic trilostane capsules are available and typically cost 30–50% less. Compounded trilostane is also an option but the FDA notes that compounded medications lack the same bioavailability guarantees as FDA-approved products — discuss this trade-off with your vet.
Mitotane (Lysodren®) — The Older Protocol
Mitotane is an adrenolytic agent — it selectively destroys the zona fasciculata and zona reticularis layers of the adrenal cortex, reducing cortisol output. Treatment involves a "loading phase" (daily dosing for 5–10 days until cortisol drops) followed by a "maintenance phase" (dosing 1–2 times per week). The loading phase requires close monitoring for signs of Addisonian crisis: lethargy, vomiting, diarrhea, collapse. If these occur, you stop mitotane immediately and contact your vet — your dog may need emergency corticosteroid replacement.
While mitotane is less commonly used as first-line therapy today, some veterinary endocrinologists still prefer it for specific cases, particularly when trilostane is poorly tolerated or unavailable.
Surgical Options: When Is Surgery the Right Call?
Adrenalectomy is the treatment of choice for dogs with a benign, unilateral adrenal tumor (ADH) when no evidence of metastasis or vascular invasion exists on ultrasound. The surgery requires a skilled soft-tissue surgeon or veterinary surgical specialist. Dogs are typically stabilized on trilostane for 4–8 weeks before surgery to reduce cortisol levels and surgical risk. Post-operatively, the remaining adrenal gland is atrophied and cannot immediately produce adequate cortisol — your dog will need temporary corticosteroid supplementation (prednisone, tapering over 2–4 months) while the gland recovers.
Hypophysectomy (transsphenoidal removal of the pituitary tumor) is offered at only a handful of specialty centers in the United States. It's most appropriate for dogs with PDH that is poorly responsive to medical management or where a macrotumor is causing neurological compression. Recovery requires careful monitoring for diabetes insipidus (inability to concentrate urine) and hypothyroidism, both of which may be temporary or permanent.
Prognosis and Life Expectancy for Dogs with Cushing's Disease
The prognosis for Cushing's disease varies significantly based on the form, tumor characteristics, and how early treatment begins. Here's what the veterinary literature tells us:
| Disease Form | Median Survival (Treated) | Median Survival (Untreated) | Key Prognostic Factors |
|---|---|---|---|
| PDH (microtumor, <10mm) | 2–2.5 years (many live 3–5+ years with good management) | ~1 year | Response to trilostane; development of secondary diabetes; concurrent kidney disease |
| PDH (macrotumor, >10mm) | 6–18 months (varies with tumor growth rate) | 3–6 months | Tumor growth rate; neurological symptom severity; response to radiation |
| ADH (benign, surgical candidate) | Curative with successful adrenalectomy; normal lifespan expected | 6–18 months | Surgical outcome; absence of vascular invasion; tumor size |
| ADH (malignant / metastatic) | 6–12 months with medical management | 3–6 months | Extent of metastasis; response to trilostane for symptom control |
| Iatrogenic Cushing's | Reversible with gradual steroid tapering; normal lifespan if underlying condition managed | Depends on underlying condition | Rate of steroid taper; whether underlying condition requires ongoing steroids |
It's worth emphasizing that many dogs with pituitary-dependent Cushing's disease live full, comfortable lives for years after diagnosis when their cortisol is well-controlled with trilostane. The key variables are consistent medication administration, regular monitoring blood work, and early intervention for complications.
Home Care and Daily Management
Managing Cushing's disease is a long-term commitment. Here's what daily life looks like for a dog on treatment:
Medication Administration
Trilostane should be given with food to improve absorption and reduce GI side effects. Use the same type of meal each time (consistency matters for reliable drug absorption). Set a daily alarm — missed doses cause cortisol rebound, and doubling up risks an Addisonian crisis. Keep a medication log noting the date, time, dose, and any observed side effects.
Monitoring at Home
- Track water intake: Measure daily water consumption (mL or cups). A well-controlled Cushing's dog should see thirst normalize within 2–4 weeks of starting treatment. Persistent polydipsia suggests inadequate dosing.
- Monitor appetite: Ravenous hunger should decrease within 1–3 weeks. Continued excessive appetite may indicate the dose needs adjustment.
- Watch for Addisonian signs: Lethargy, vomiting, diarrhea, weakness, or collapse are signs of overtreatment (cortisol too low). Stop trilostane and call your vet immediately — this is an emergency.
- Coat and skin checks: Hair regrowth is slow — expect 3–6 months for visible improvement. Take monthly photos to track progress objectively.
- Weight and body condition: Weigh your dog monthly. The pot-bellied appearance gradually improves as abdominal muscle tone returns over 2–6 months.
Dietary Considerations
There is no specific "Cushing's diet," but nutritional adjustments can support your dog's health:
- Moderate fat, high-quality protein: Dogs with Cushing's are prone to hyperlipidemia (elevated blood fats). Choose a diet with moderate fat content (10–15% on a dry matter basis) and highly digestible protein.
- Controlled sodium: If your dog has concurrent hypertension, a lower-sodium diet helps manage blood pressure.
- Frequent, smaller meals: Can help manage persistent hunger between meals without excessive caloric intake.
- Avoid calcium supplements unless directed by your vet — Cushing's dogs are already prone to calcium deposits in skin and soft tissues.
Exercise and Lifestyle
Maintain regular, moderate exercise appropriate for your dog's age and fitness level. Short, daily walks are better than intense weekend activities. Swimming is excellent low-impact exercise for dogs with muscle weakness. Avoid overexertion in hot weather — Cushing's dogs have impaired thermoregulation due to excess cortisol and may overheat more easily.
The Real Cost of Treating Cushing's Disease in Dogs
Cushing's disease is a chronic condition requiring lifelong management for most dogs. Here's a realistic breakdown of what you can expect to spend:
| Expense Category | Year 1 (Diagnosis + Stabilization) | Ongoing Annual Cost |
|---|---|---|
| Diagnostic workup (blood work, hormone tests, ultrasound) | $800–$2,000 | — |
| Trilostane medication (varies by dog size/dose) | $500–$1,400 | $500–$1,400 |
| Monitoring blood work (ACTH stim tests, chemistry panels) | $600–$1,200 (3–4 visits in year 1) | $300–$600 (2 visits/year) |
| Vet office visit fees | $300–$600 | $150–$300 |
| Treatment of complications (UTIs, skin infections, hypertension meds) | $200–$800 | $100–$500 |
| TOTAL ESTIMATED | $2,400–$6,000 | $1,050–$2,800/year |
Worst-case scenarios: If your dog develops secondary diabetes (requiring insulin and glucose monitoring), add $1,500–$3,000 annually. If surgery is pursued (adrenalectomy or hypophysectomy), expect a one-time cost of $3,000–$10,000 but potentially lower ongoing medication costs. Emergency treatment for an Addisonian crisis (IV fluids, dexamethasone, hospitalization) typically costs $500–$2,000 per event.
Pet insurance considerations: Most comprehensive pet insurance policies cover Cushing's disease treatment if the diagnosis is made after the policy's waiting period. However, Cushing's is typically classified as a chronic/endocrine condition, and some policies have annual or lifetime payout caps that can be reached within 2–3 years of treatment. Review your policy's terms carefully. Average monthly premiums for a dog with Cushing's coverage range from $45–$90/month depending on breed, age, and deductible.
Frequently Asked Questions About Cushing's Disease in Dogs
Can Cushing's disease in dogs be cured?
It depends on the form. Adrenal-dependent Cushing's caused by a benign, surgically accessible tumor can be cured with adrenalectomy — approximately 75–90% of these dogs return to normal adrenal function post-surgery. Pituitary-dependent Cushing's (80–85% of cases) is not curable in the traditional sense; it requires lifelong medical management. However, "cured" and "well-managed" are different things — most dogs with PDH on trilostane live comfortable, symptom-free lives for years. Hypophysectomy at specialized centers can achieve long-term remission in some PDH cases.
What happens if Cushing's disease is left untreated?
Untreated Cushing's disease is progressive and ultimately life-threatening. Over months to years, chronically elevated cortisol causes immune suppression (recurrent infections), muscle wasting, diabetes mellitus, hypertension, kidney damage, blood clot formation (thromboembolism), and neurological deterioration if a pituitary tumor grows. Median survival for untreated Cushing's dogs is approximately 1 year from diagnosis, with quality of life declining significantly in the final months. Treatment is strongly recommended unless your dog has other terminal conditions that make management impractical.
Is Cushing's disease painful for dogs?
Cushing's disease is not typically painful in the way that arthritis or cancer might be, but it causes significant discomfort. Muscle weakness makes movement difficult, skin infections cause itching and irritation, the distended abdomen can feel uncomfortable, and excessive hunger is distressing. Complications like pancreatitis, urinary tract infections, and blood clots are painful. Most owners report a dramatic improvement in their dog's energy, comfort, and overall demeanor within 2–4 weeks of starting trilostane.
Can I use natural or holistic treatments instead of medication?
There is no peer-reviewed evidence that any supplement, herb, or alternative therapy can normalize cortisol levels in dogs with Cushing's disease. Some supplements marketed for "adrenal support" (such as melatonin, lignans from flaxseed, or ashwagandha) have been studied in limited contexts — melatonin, for instance, may mildly inhibit cortisol synthesis in vitro — but none have demonstrated clinically meaningful results in controlled veterinary trials. Using unproven alternatives in place of trilostane or mitotane allows the disease to progress unchecked. If you're interested in complementary approaches, discuss them with your veterinarian as additions to — not replacements for — evidence-based treatment.
How often does my dog need blood work once stabilized on trilostane?
After the initial stabilization period (testing at 2 weeks, 4 weeks, and 12 weeks), most veterinary endocrinologists recommend ACTH stimulation testing and a chemistry panel every 3–6 months for life. More frequent monitoring is needed if dose adjustments are made, if your dog shows any signs of illness, or if concurrent conditions (diabetes, kidney disease) develop. Each monitoring visit typically costs $150–$300 including the ACTH stim test and vet exam.
My dog was just diagnosed — what should I do first?
Take a breath. Cushing's disease is manageable, and starting treatment is the most important step. Your immediate action plan:
- Fill the trilostane prescription and begin dosing exactly as your vet directed, with food, at the same time daily.
- Set up a tracking system — a simple notebook or phone app to log daily water intake, appetite, urination frequency, and any symptoms.
- Schedule your first recheck (ACTH stim test) for 10–14 days after starting medication.
- Learn the signs of Addisonian crisis (lethargy, vomiting, collapse) so you can act quickly if over-treatment occurs.
- Review your finances — budget approximately $100–$250/month for medication and monitoring going forward.
Cushing's disease is a marathon, not a sprint. With consistent medication, regular monitoring, and a strong partnership with your veterinarian, most dogs go on to live happy, comfortable lives well beyond their diagnosis.
Aaron Whyte
All our authors care for dogs every day — read more of their work on the authors page.
