Cushing's in Dogs: Symptoms, Diagnosis, and Treatment Guide
Recognize Cushing's in dogs symptoms early. Learn about diagnosis tests, treatment options, costs, prognosis, and daily management for hyperadrenocorticism.
If your dog is drinking excessively, losing hair in patches, and developing a pot-bellied appearance, you may be noticing Cushing's in dogs symptoms — one of the most common endocrine disorders in middle-aged and older canines. Cushing's disease, medically known as hyperadrenocorticism (HAC), occurs when the body produces too much cortisol, the stress hormone. According to the Merck Veterinary Manual, approximately 1 to 2 in every 1,000 dogs develop Cushing's each year, making it a condition every dog owner should understand.
Roughly 80–85% of Cushing's cases are pituitary-dependent (PDH), caused by a benign tumor on the pituitary gland that overproduces ACTH, stimulating the adrenal glands to pump out excess cortisol. 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. Understanding which type your dog has is critical because treatment paths and prognosis differ significantly.
What Causes Cushing's Disease in Dogs?
Cortisol is essential for life — it regulates metabolism, immune response, blood pressure, and stress adaptation. But when cortisol levels remain chronically elevated, the effects cascade through nearly every organ system. Here is how each form develops:
- Pituitary-Dependent Hyperadrenocorticism (PDH): A microadenoma (small benign tumor) or, less commonly, a macroadenoma (larger tumor >10mm) on the pituitary gland secretes excessive adrenocorticotropic hormone (ACTH). This signals both adrenal glands to enlarge and overproduce cortisol. PDH accounts for 80–85% of naturally occurring cases.
- Adrenal-Dependent Hyperadrenocorticism (ADH): A tumor on one adrenal gland autonomously secretes cortisol, independent of pituitary signaling. About 50% of adrenal tumors are benign adenomas; the other 50% are malignant carcinomas. This form represents 15–20% of cases.
- Iatrogenic Cushing's: Long-term administration of glucocorticoid drugs (prednisone, dexamethasone, methylprednisolone) for conditions like allergies, autoimmune disease, or arthritis causes clinical signs identical to naturally occurring Cushing's. This form is fully reversible with a supervised medication taper.
Recognizing Cushing's in Dogs: Symptoms by Severity
The hallmark challenge of Cushing's disease is that early symptoms are subtle and easily mistaken for normal aging. Many owners don't suspect illness until advanced signs appear. Use this checklist to evaluate your dog's symptoms:
| Severity | Symptom | What You'll Notice |
|---|---|---|
| Early Warning Signs | Increased thirst (polydipsia) | Drinking noticeably more water; bowl empties faster than usual |
| Increased urination (polyuria) | More frequent potty breaks, accidents in house-trained dogs, larger urine volume | |
| Increased appetite (polyphagia) | Acting ravenously hungry, begging, scavenging, stealing food | |
| Mild panting | Panting more than usual without exercise or heat exposure | |
| Slightly reduced energy | Less enthusiasm for walks, sleeping more during the day | |
| Thinning coat | Coat looks less lustrous; slower regrowth after grooming or shedding | |
| Advanced Symptoms | Bilateral symmetrical hair loss (alopecia) | Hair loss on flanks, abdomen, and trunk — typically sparing the head and legs |
| Pot-bellied appearance | Abdominal distension from weakened abdominal muscles and fat redistribution | |
| Muscle wasting | Visible thinning of limb muscles; spine and hip bones more prominent | |
| Thin, fragile skin | Skin tears easily; visible bruising; slow wound healing | |
| Calcinosis cutis | Hard, gritty, calcium-encrusted patches on the skin (especially back and groin) | |
| Recurrent infections | Ear infections, urinary tract infections, skin infections that keep returning | |
| Reproductive changes | Testicular atrophy in males; absent heat cycles in intact females |
A useful rule of thumb: if your dog is over 7 years old and you've noticed a combination of increased thirst and increased urination alongside any coat changes, Cushing's should be on your vet's differential list.
Breed Predisposition and Risk Factors
Who is most at risk for Cushing's disease?
- Age: Most commonly diagnosed in dogs aged 7–12 years. Rare in dogs under 6.
- Breed predisposition (PDH): Poodles (especially Miniature and Toy), Dachshunds, Small Terriers (Yorkshire, Boston, Cairn), Beagles, and Cocker Spaniels.
- Breed predisposition (ADH): Larger breeds over 44 lb (20 kg) are slightly overrepresented for adrenal tumors — German Shepherds and Labrador Retrievers appear more frequently in adrenal carcinoma studies.
- Sex: Females have a slightly higher incidence (roughly 3:2 female-to-male ratio for PDH).
- Weight: Overweight dogs are not more likely to develop Cushing's, but obesity can mask early symptoms and complicate diagnosis.
- Medication history: Dogs on long-term corticosteroid therapy (even topical or ear-drop steroids used chronically) are at risk for iatrogenic Cushing's.
The American Kennel Club notes that while any breed can develop Cushing's, the genetic predisposition in certain small breeds suggests a heritable component that responsible breeders should monitor.
How Veterinarians Diagnose Cushing's Disease
Diagnosing Cushing's is genuinely one of the more complex workups in veterinary endocrinology. No single test provides a definitive answer in every case, and false positives and false negatives are common. Here is the typical diagnostic pathway your veterinarian will follow:
Step 1: Baseline Blood Work & Urinalysis
A complete blood count (CBC), serum chemistry panel, and urinalysis establish your dog's baseline health. Cushing's often shows characteristic patterns: elevated alkaline phosphatase (ALP), elevated cholesterol, diluted urine (low specific gravity), and sometimes elevated liver enzymes. Cost: $150–$300.
Step 2: Screening Tests (Confirming Cushing's)
If baseline results and clinical signs suggest HAC, your vet will run one or both screening tests:
- Low-Dose Dexamethasone Suppression Test (LDDST): Blood is drawn, a small dose of dexamethasone is injected, and blood is drawn again at 4 and 8 hours. In a healthy dog, dexamethasone suppresses cortisol production. In a Cushing's dog, cortisol remains elevated. This is considered the most sensitive screening test. Cost: $200–$350.
- ACTH Stimulation Test: Synthetic ACTH is injected, and cortisol is measured before and 1 hour after. An exaggerated cortisol response suggests Cushing's. This test is less sensitive for PDH (misses 15–20% of cases) but is useful for iatrogenic Cushing's and adrenal tumors. Cost: $150–$300.
- Urine Cortisol:Creatinine Ratio (UCCR): A simple at-home urine collection test. A normal result effectively rules out Cushing's, but an elevated result only means further testing is needed — it's not diagnostic on its own. Cost: $50–$100.
Step 3: Differentiating PDH from ADH
Once Cushing's is confirmed, your vet needs to determine which type:
- High-Dose Dexamethasone Suppression Test (HDDST): A higher dexamethasone dose may suppress cortisol in PDH but not in ADH. Cost: $200–$350.
- Endogenous ACTH Levels: High ACTH suggests PDH; low or undetectable ACTH suggests ADH. This test requires special sample handling (frozen, shipped overnight). Cost: $150–$250.
- Abdominal Ultrasound: Visualizes the adrenal glands. Bilateral enlargement suggests PDH; a single enlarged gland with a normal or atrophied opposite gland suggests ADH. Also detects adrenal tumors and assesses for invasion into nearby blood vessels. Cost: $300–$600.
- CT or MRI (for pituitary macroadenomas): Recommended if neurological signs are present or if an adrenal tumor is suspected and surgical planning is needed. Cost: $1,000–$2,500.
Total diagnostic cost estimate: Expect to spend $500–$1,500 for a standard workup (bloodwork, LDDST, abdominal ultrasound). Add $1,000–$2,500 if advanced imaging (CT/MRI) is needed.
Treatment Options for Cushing's Disease in Dogs
Treatment depends entirely on which type of Cushing's your dog has, the severity of symptoms, and whether complications like diabetes or hypertension are present.
| Treatment | Used For | How It Works | Success Rate | Ongoing Cost |
|---|---|---|---|---|
| Trilostane (Vetoryl®) | PDH and ADH | Inhibits 3β-hydroxysteroid dehydrogenase, blocking cortisol synthesis in the adrenal glands | 85–93% clinical improvement within 4–8 weeks | $40–$120/month depending on dose and dog size |
| Mitotane (Lysodren®) | PDH and ADH | Selectively destroys the cortisol-producing layer of the adrenal cortex | 80–90% response rate; higher risk of adrenal insufficiency | $30–$80/month |
| Adrenalectomy (surgical removal) | ADH (benign adenoma) | Removes the tumor-bearing adrenal gland; potential cure | Cure rate ~85% for benign tumors; perioperative mortality 5–10% | $2,500–$5,000 surgery + hospitalization |
| Hypophysectomy (pituitary surgery) | PDH (select cases) | Removes the pituitary tumor; available at limited specialty centers | Long-term remission in 70–80%; requires specialized surgeon | $5,000–$8,000+ |
| Radiation therapy | PDH with macroadenoma | Targets pituitary tumor to reduce size and ACTH production | Variable; controls neurological signs in ~75% of macroadenoma cases | $3,000–$6,000 for full course |
| Medication taper | Iatrogenic Cushing's | Gradual reduction of exogenous corticosteroid under veterinary supervision | Full resolution expected over weeks to months | Minimal (tapering visits only) |
Trilostane (Vetoryl®) — The Current Standard of Care
Trilostane has become the first-line medical treatment for both PDH and ADH since receiving FDA approval for veterinary use. It is administered orally, typically once daily (some protocols use twice-daily dosing for better 24-hour cortisol control). Clinical improvement — reduced drinking, improved coat, increased energy — is usually visible within 2 to 4 weeks, with full effects by 8 to 12 weeks.
Monitoring protocol for trilostane: Your vet will schedule ACTH stimulation tests at approximately 10–14 days, 30 days, 90 days, and then every 3–6 months for life. Dosage adjustments are common. Expect to spend $200–$350 per monitoring visit.
Side effects to watch for: Lethargy, vomiting, diarrhea, decreased appetite, and — rarely — an Addisonian crisis (acute adrenal insufficiency), which is a medical emergency. If your dog on trilostane becomes acutely weak, collapses, or has severe vomiting/diarrhea, contact your vet immediately.
Can Cushing's Disease Be Cured?
For PDH, medical management with trilostane or mitotane controls the disease but does not cure it. Your dog will likely need lifelong medication and monitoring. Surgical hypophysectomy offers a potential cure but is available at very few veterinary specialty hospitals worldwide and carries significant risk.
For ADH with a benign adenoma, surgical removal of the affected adrenal gland can be curative. Dogs that survive the perioperative period and recover fully often require no further treatment. Malignant adrenal carcinomas have a guarded prognosis due to invasion into surrounding tissues and metastasis risk.
Iatrogenic Cushing's is the only form that is fully reversible — once the causative medication is tapered off, symptoms gradually resolve over several weeks to months.
Prognosis and Life Expectancy
| Type | Median Survival Time | Key Prognostic Factors |
|---|---|---|
| PDH (well-managed with trilostane) | 2.0–2.5 years from diagnosis (many dogs live 3–5+ years) | Age at diagnosis, comorbidities (diabetes, hypertension), owner compliance with monitoring |
| PDH with pituitary macroadenoma | 6–18 months (depends on tumor growth rate and neurological involvement) | Tumor size, response to radiation, presence of neurological signs |
| ADH — benign adenoma (surgical) | 18 months to 3+ years; potential cure | Surgical success, perioperative complications, completeness of resection |
| ADH — malignant carcinoma | 6–12 months with treatment; shorter without | Vascular invasion, metastasis at diagnosis, surgical feasibility |
| Iatrogenic Cushing's | Normal life expectancy once medication is tapered | Underlying condition requiring the corticosteroid; adrenal recovery time |
It's important to understand that these are median figures from published veterinary studies. Individual outcomes vary widely. Many dogs with well-managed PDH live full, comfortable lives for years after diagnosis. The American Veterinary Medical Association recommends working with a veterinarian experienced in endocrine management to optimize long-term outcomes.
Home Care and Daily Management
Managing a dog with Cushing's at home requires consistency and observation. Here is what daily life looks like:
Medication Administration
Trilostane must be given with food to improve absorption. Give it at the same time every day. If you miss a dose, give it as soon as you remember — unless it's close to the next scheduled dose. Never double-dose. Store capsules at room temperature, away from moisture. Keep all medication out of reach of children and other pets.
Water and Bathroom Access
Even with treatment, your dog may drink and urinate more than a healthy dog for several weeks while cortisol levels normalize. Ensure constant access to fresh water. Provide more frequent potty breaks or consider pee pads if your dog struggles to hold it overnight during the initial treatment phase.
Diet and Nutrition
Feed a balanced, AAFCO-approved diet appropriate for your dog's life stage. Dogs with Cushing's often have increased appetite — resist the urge to overfeed. Work with your vet to calculate ideal caloric intake based on target weight, not current weight if your dog is overweight. A moderate-protein, moderate-fat diet supports muscle maintenance without exacerbating metabolic stress. If your dog also has concurrent diabetes (which occurs in roughly 10–15% of Cushing's cases), your vet may recommend a prescription diabetic diet.
Skin and Coat Care
Hair regrowth after starting treatment can take 3–6 months and may never fully return to pre-disease appearance. Bathe with gentle, moisturizing shampoos if skin is thin or fragile. Monitor for calcinosis cutis lesions and report any new hard patches or open sores to your vet. Keep nails trimmed, as muscle weakness can alter gait and increase nail wear unevenly.
Monitoring at Home
Keep a symptom journal tracking daily water intake (measure the bowl), urination frequency, appetite, energy level, and any vomiting or diarrhea. Bring this log to every recheck appointment — it is invaluable for dosage adjustments.
🚨 When to Call Your Vet Immediately
Contact your veterinarian or an emergency clinic if your dog on Cushing's treatment shows any of these red flags:
- Acute lethargy, weakness, or collapse (possible Addisonian crisis)
- Severe or persistent vomiting and diarrhea
- Complete loss of appetite lasting more than 24 hours
- Sudden disorientation, circling, head pressing, or seizures (possible pituitary macroadenoma expansion)
- Rapid abdominal swelling or signs of pain (possible adrenal tumor rupture or pancreatitis)
- Excessive panting or difficulty breathing (possible pulmonary thromboembolism — Cushing's dogs have increased blood clot risk)
An Addisonian crisis from trilostane overdose is a life-threatening emergency. If your dog collapses or becomes profoundly weak, stop trilostane and seek emergency veterinary care immediately. Your vet will administer IV fluids and glucocorticoids to stabilize your dog.
How Much Does Cushing's Treatment Cost?
Budgeting for Cushing's disease is important because it is a lifelong commitment. Here is a realistic breakdown based on 2025–2026 veterinary pricing across the United States:
- Initial diagnostic workup: $500–$1,500 (bloodwork, LDDST or ACTH stim, abdominal ultrasound). Add $1,000–$2,500 if CT or MRI is needed.
- Trilostane (Vetoryl®) monthly cost: $40–$120/month depending on dog size and dose. A 30 mg capsule costs approximately $2–$4; a 60 mg capsule costs $3–$6. Larger dogs may require 120 mg or more daily.
- Monitoring visits: $200–$350 per visit (ACTH stim test + exam). Expect 4–6 visits in the first year, then 2–4 visits annually. Annual monitoring cost: $400–$1,400.
- Annual medication + monitoring total: $900–$2,800/year for most dogs.
- Adrenalectomy (surgical): $2,500–$5,000 including pre-surgical imaging, surgery, and 2–3 day hospitalization.
- Hypophysectomy: $5,000–$8,000+ at the limited number of specialty centers that perform it.
- Radiation therapy: $3,000–$6,000 for a full course (typically 10–18 fractions over 3–5 weeks).
- Worst-case scenario (emergency Addisonian crisis): $1,500–$4,000 for emergency hospitalization, IV fluids, and intensive care.
Pet insurance can significantly offset these costs if your dog is enrolled before diagnosis. Most comprehensive plans cover Cushing's diagnosis and ongoing treatment, though pre-existing condition exclusions apply. If your dog is a breed predisposed to Cushing's, enrolling in insurance during puppyhood or early adulthood is financially prudent.
Frequently Asked Questions
What is Cushing's disease in dogs?
Cushing's disease (hyperadrenocorticism) is an endocrine disorder where the body produces chronically excessive levels of cortisol. It is most commonly caused by a benign pituitary tumor (PDH), less commonly by an adrenal tumor (ADH), and sometimes by long-term steroid medication use (iatrogenic). It primarily affects middle-aged to older dogs and requires lifelong management in most cases.
What are the earliest symptoms of Cushing's in dogs?
The earliest signs are increased thirst (polydipsia), increased urination (polyuria), and increased appetite (polyphagia) — collectively called the "three P's." These are often accompanied by subtle coat changes and slightly reduced energy. Because these signs overlap with diabetes, kidney disease, and normal aging, veterinary testing is essential for accurate diagnosis.
How is Cushing's disease diagnosed in dogs?
Diagnosis requires a combination of clinical signs, baseline bloodwork, and specific endocrine tests — most commonly the low-dose dexamethasone suppression test (LDDST) and/or ACTH stimulation test. An abdominal ultrasound helps differentiate between pituitary-dependent and adrenal-dependent forms. No single test is 100% accurate, so a combination approach is standard.
Can Cushing's disease in dogs be cured?
Pituitary-dependent Cushing's is generally not curable but is highly manageable with daily medication (trilostane) and regular monitoring. Adrenal-dependent Cushing's caused by a benign adenoma can be cured with surgical removal of the affected adrenal gland. Iatrogenic Cushing's resolves when the causative steroid medication is gradually tapered off under veterinary supervision.
What is the life expectancy of a dog with Cushing's disease?
Dogs with well-managed pituitary-dependent Cushing's have a median survival time of 2 to 2.5 years from diagnosis, with many living 3 to 5 years or longer. Dogs with benign adrenal tumors that undergo successful surgery may be cured and live a normal lifespan. Prognosis is more guarded for malignant adrenal tumors and pituitary macroadenomas.
Which dog breeds are most prone to Cushing's disease?
Poodles (especially Miniature and Toy), Dachshunds, Small Terriers (Yorkshire Terriers, Boston Terriers, Cairn Terriers), Beagles, and Cocker Spaniels are overrepresented in Cushing's cases. However, any breed can develop the condition, particularly in the 7–12 year age range.
Is Cushing's disease painful for dogs?
Cushing's itself is not typically painful, but its complications can cause discomfort: recurrent skin infections, urinary tract infections, muscle weakness, and calcinosis cutis lesions can all reduce quality of life. Dogs with pituitary macroadenomas may experience headaches or neurological discomfort as the tumor grows. Proper treatment significantly improves comfort and wellbeing.
Can I treat my dog's Cushing's naturally without medication?
There is no scientifically validated natural or holistic treatment that effectively controls Cushing's disease. Supplements marketed for "adrenal support" have not been shown in peer-reviewed studies to reduce cortisol levels or improve clinical outcomes. Untreated Cushing's leads to progressive deterioration, including risk of diabetes, hypertension, blood clots, and organ damage. Always consult your veterinarian before attempting alternative treatments — medical management with trilostane is the evidence-based standard of care.
How much does it cost to treat Cushing's disease in a dog annually?
Expect to spend approximately $900–$2,800 per year on medication (trilostane) and monitoring visits for a dog with pituitary-dependent Cushing's. Costs are higher in the first year due to the initial diagnostic workup ($500–$1,500+) and more frequent monitoring visits. Surgical options for adrenal tumors range from $2,500–$5,000 as a one-time cost.
Disclaimer: This article is for informational purposes only and does not replace professional veterinary advice. If you suspect your dog has Cushing's disease, consult your veterinarian for proper diagnosis and treatment. Never start, stop, or adjust medication without veterinary guidance.
Marcus Aldridge
All our authors care for dogs every day — read more of their work on the authors page.
