The First Signs of Cushing's Disease in Dogs?
Learn what the first signs of Cushing's disease in dogs look like, how it's diagnosed, treatment options, costs, and life expectancy for affected dogs.
What Is Cushing's Disease in Dogs?
Cushing's disease, clinically known as hyperadrenocorticism (HAC), is an endocrine disorder caused by prolonged exposure to excessive cortisol — the body's primary stress hormone. In healthy dogs, cortisol regulates metabolism, immune response, and blood pressure. When the adrenal glands overproduce cortisol, or when the pituitary gland sends constant stimulation signals, the result is a cascade of metabolic disruptions that affect nearly every organ system.
Approximately 80–85% of cases are pituitary-dependent hyperadrenocorticism (PDH), where a small benign tumor on the pituitary gland overproduces ACTH (adrenocorticotropic hormone), which in turn stimulates the adrenal glands. 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 long-term steroid medication use. 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.
What Are the First Signs of Cushing's Disease in Dogs?
The earliest indicators of Cushing's disease are often subtle and easy to dismiss as normal aging. Most owners first notice increased thirst and urination — a combination veterinarians call PU/PD (polyuria/polydipsia). Your dog may start asking to go outside more frequently, having accidents in the house despite being previously reliable, or drinking noticeably more water throughout the day. A dog that previously consumed 3 cups of water daily may suddenly drink 6–8 cups.
Increased appetite (polyphagia) is another hallmark early sign. Your dog may seem constantly hungry, beg more aggressively, or even steal food. These three symptoms — excessive thirst, excessive urination, and excessive hunger — form what veterinarians call the "classic triad" of early Cushing's disease.
Symptom Checklist by Severity
| Severity | Symptoms | Typical Onset |
|---|---|---|
| Early Warning Signs |
|
Months 1–3 of disease progression |
| Moderate Symptoms |
|
Months 3–8 of disease progression |
| Advanced Symptoms |
|
Months 8+ untreated, or with macroadenoma progression |
The key insight many owners miss: early-stage Cushing's doesn't look dramatic. A 9-year-old poodle drinking a bit more water and seeming hungrier than usual doesn't trigger alarm bells. It's only when the pot belly and hair loss develop months later that owners connect the dots. If you notice the classic triad persisting for more than 2–3 weeks, schedule a veterinary appointment.
Which Breeds Are Prone to Cushing's Disease? Risk Factors Explained
Risk Factors for Canine Cushing's Disease
- Age: Most commonly diagnosed in dogs aged 7–12 years; rare in dogs under 6
- Breed predisposition: Poodles (especially miniature and toy), Dachshunds, Boston Terriers, Yorkshire Terriers, German Shepherds, Beagles, and Cocker Spaniels show higher incidence
- Sex: Female dogs are slightly more likely to develop PDH; adrenal tumors show no strong sex bias
- Size: Smaller breeds (under 44 lb / 20 kg) are more commonly affected by PDH; larger breeds are somewhat more likely to develop adrenal-dependent forms
- Medication history: Long-term corticosteroid use (prednisone, dexamethasone, methylprednisolone) for allergies, autoimmune disease, or other conditions can cause iatrogenic Cushing's
- Genetics: Familial clustering has been observed in some breeds, though no single gene has been definitively identified
According to the American Kennel Club, Poodles, Dachshunds, and Boston Terriers appear overrepresented in Cushing's disease statistics. However, any breed can develop this condition. If your dog is over 7, belongs to a predisposed breed, and has a history of steroid medication use, they carry elevated risk and warrant closer monitoring during routine wellness exams.
How Is Cushing's Disease Diagnosed in Dogs?
Diagnosing Cushing's disease is one of the more complex processes in veterinary endocrinology. No single test provides a definitive answer in every case. Your veterinarian will typically follow a staged diagnostic approach, starting with screening tests and progressing to confirmatory testing.
Stage 1: Initial Screening (Suspicion Phase)
When your vet suspects Cushing's based on clinical signs, they'll first run a complete blood count (CBC), serum biochemistry panel, and urinalysis. These baseline tests don't diagnose Cushing's directly but reveal supportive patterns:
- Elevated alkaline phosphatase (ALP): One of the most consistent lab findings — often 2–5× normal range
- Elevated ALT (alanine aminotransferase): Mildly elevated liver enzymes
- Stress leukogram: Elevated neutrophils, decreased lymphocytes and eosinophils
- Dilute urine: Urine specific gravity (USG) below 1.020, often below 1.015
- Elevated cholesterol and triglycerides: Reflecting altered fat metabolism
Stage 2: Confirmatory Testing
If screening results support the suspicion, your vet will order one or more of these specific diagnostic tests:
| Test | How It Works | Accuracy | Estimated Cost |
|---|---|---|---|
| Low-Dose Dexamethasone Suppression Test (LDDST) | Injects a small dose of dexamethasone; measures cortisol at 0, 4, and 8 hours. In healthy dogs, cortisol suppresses. In Cushing's dogs, it does not. | ~90–95% sensitivity for PDH | $200–$350 |
| ACTH Stimulation Test | Injects synthetic ACTH; measures cortisol before and 1 hour after. An exaggerated response suggests Cushing's. | ~80–85% sensitivity for PDH; ~60% for ADH | $150–$300 |
| Urine Cortisol:Creatinine Ratio (UCCR) | Measures cortisol excreted in a morning urine sample at home (to avoid stress-induced cortisol elevation at the clinic). | High sensitivity (~95%) but low specificity — good for ruling OUT Cushing's | $50–$100 |
Stage 3: Differentiating PDH from ADH
Once Cushing's is confirmed, your vet needs to determine whether it's pituitary-dependent or adrenal-dependent, because treatment pathways differ significantly:
- High-Dose Dexamethasone Suppression Test (HDDST): Helps differentiate PDH from ADH — PDH tumors often partially suppress with high-dose dexamethasone, while adrenal tumors do not. Cost: $200–$350.
- Endogenous ACTH levels: Blood test measuring baseline ACTH. High ACTH suggests PDH; low/undetectable ACTH suggests ADH. Cost: $100–$200, but the sample must be handled very carefully (frozen, shipped to a reference lab).
- Abdominal ultrasound: Visualizes the adrenal glands. Bilaterally enlarged adrenals suggest PDH; one enlarged and one atrophied adrenal suggests ADH. Cost: $300–$600.
- CT or MRI of the brain: Gold standard for visualizing pituitary tumors, particularly macroadenomas (tumors >10 mm). Cost: $1,500–$3,000+.
Total Diagnostic Cost Estimates
| Basic workup (CBC, chemistry, urinalysis, one confirmatory test): | $400–$800 |
| Full endocrine workup (baseline labs, LDDST, ACTH stim, differentiation tests): | $800–$1,500 |
| Advanced imaging (ultrasound + CT/MRI if needed): | $1,800–$4,000+ |
Can Cushing's Disease in Dogs Be Treated?
Cushing's disease is generally manageable rather than curable, with the exception of some adrenal tumors that can be surgically removed. Treatment approach depends on the type of Cushing's, the severity of symptoms, and the presence of a pituitary macroadenoma.
| Treatment | Used For | How It Works | Success Rate / Notes | Monthly Cost |
|---|---|---|---|---|
| Trilostane (Vetoryl®) | PDH and ADH — first-line treatment | Inhibits the enzyme 3-beta-hydroxysteroid dehydrogenase, blocking cortisol synthesis in the adrenal glands | Clinical improvement in 70–85% of dogs within 2–4 weeks; requires lifelong administration | $40–$150/month depending on dog size and dose |
| Mitotane (Lysodren®) | PDH — alternative to trilostane | Selectively destroys the cortisol-producing layers of the adrenal cortex (medical adrenalectomy) | Effective in ~70–80% of cases; requires careful induction phase with risk of Addisonian crisis if overdosed | $30–$100/month |
| Adrenalectomy (surgical) | ADH — adrenal tumor removal | Surgical removal of the affected adrenal gland | Curative for benign adenomas; perioperative mortality ~5–10%; malignant carcinomas have high recurrence rates | $3,000–$7,000 (one-time surgical cost) |
| Radiation therapy | PDH with macroadenoma causing neurological signs | Targets and shrinks the pituitary tumor to relieve brain compression | Improves neurological symptoms in ~70–80% of cases; does not normalize cortisol production (medical therapy still needed) | $4,000–$8,000 (course of treatment) |
| Iatrogenic management | Steroid-induced Cushing's | Gradual tapering of exogenous steroid medication under veterinary supervision | Usually reversible over weeks to months once steroids are withdrawn; underlying condition may require alternative treatment | Variable — depends on alternative therapy needed |
Trilostane (Vetoryl®) has largely replaced mitotane as the first-line treatment for PDH since its FDA approval for veterinary use. It's generally better tolerated, has fewer severe side effects, and doesn't carry the risk of permanent adrenal destruction. Most dogs on trilostane require twice-daily dosing with food, with ACTH stimulation monitoring at 10–14 days, 30 days, 90 days, and then every 3–6 months for life.
What Is the Life Expectancy of a Dog With Cushing's Disease?
Prognosis varies significantly based on the type of Cushing's, tumor size, and how early the disease is caught. Here's what the veterinary literature generally reports:
| Disease Stage / Type | Median Survival Time | Key Factors |
|---|---|---|
| PDH with microadenoma (tumor <10 mm), treated | 2–2.5 years (many dogs live 3–5+ years with good management) | Most common form; best prognosis with consistent trilostane therapy and monitoring |
| PDH with macroadenoma (tumor >10 mm), treated | 6 months to 2 years | Prognosis depends on neurological involvement; radiation can extend survival |
| ADH — benign adenoma, surgically removed | Potentially curative; normal life expectancy if surgery is successful | Best-case scenario; perioperative risk must be managed |
| ADH — malignant carcinoma | 6–18 months | High rate of metastasis (especially to liver and lungs); medical management provides palliative control |
| Untreated Cushing's (any type) | Variable — typically 1–2 years from diagnosis | Risk of fatal complications: pulmonary thromboembolism, severe infections, diabetes, kidney failure |
These are median figures — individual outcomes vary widely. Many dogs with well-managed PDH live well beyond 3 years after diagnosis with good quality of life. The key variables are early detection, consistent medication compliance, and regular veterinary monitoring.
Home Care and Daily Management
Managing a Cushing's dog at home requires consistency and attention to detail. Here's what daily life looks like:
Medication Administration
- Trilostane: Administer with food (improves absorption) — typically twice daily. Give at roughly the same times each day (e.g., 7 AM and 7 PM).
- Never skip doses without veterinary guidance — inconsistent dosing leads to cortisol fluctuations that stress the body.
- Keep a medication log noting time given, dose, and any side effects observed.
Monitoring at Home
- Track water intake: Measure daily water consumption. A decrease toward normal (approximately 1 oz per pound of body weight per day, or ~60 mL/kg) suggests the medication is working.
- Monitor appetite: Excessive hunger should diminish within 2–4 weeks of effective treatment.
- Watch urination patterns: Note frequency of outdoor breaks and any indoor accidents.
- Observe energy levels: Many dogs become noticeably more active as muscle strength returns.
- Check skin and coat: Hair regrowth may take 3–6 months after cortisol levels normalize.
Lifestyle Adjustments
- More frequent potty breaks: Until medication takes effect, plan for extra outdoor trips. Never punish accidents — your dog cannot control the increased urine production.
- Moderate exercise: Short, regular walks are beneficial. Avoid overexertion, especially in dogs with significant muscle wasting.
- Diet management: Feed a balanced, moderate-protein diet. Some veterinarians recommend diets lower in fat due to the elevated triglycerides common in Cushing's dogs. Avoid excessive treats — the increased appetite can lead to overfeeding.
- UTI vigilance: Cushing's dogs are prone to urinary tract infections due to dilute urine and immune suppression. Watch for straining, frequent small urinations, or blood in urine. Your vet may recommend periodic urine cultures even without obvious symptoms.
Monitoring Schedule After Diagnosis
Expect the following veterinary recheck timeline once treatment begins:
- 10–14 days: First ACTH stimulation test to check cortisol suppression and adjust dose
- 30 days: Second ACTH stim test, electrolyte panel (monitor for Addisonian overcorrection)
- 90 days: Full recheck including CBC, chemistry, ACTH stim
- Every 3–6 months thereafter: Ongoing monitoring for life — dose adjustments are common as the disease progresses or stabilizes
When to See the Vet: Red Flag Symptoms
🚨 Seek Immediate Veterinary Attention If Your Dog Shows:
- Sudden collapse, extreme weakness, or inability to stand — possible Addisonian crisis if on medication, or pulmonary thromboembolism
- Vomiting and diarrhea with lethargy — especially in a dog currently on trilostane or mitotane (stop medication and call your vet)
- Sudden difficulty breathing or rapid breathing at rest — possible blood clot in lungs
- Head pressing, circling, disorientation, or seizures — suggests pituitary macroadenoma pressing on brain tissue
- Sudden blindness or vision changes — macroadenoma compressing optic nerves
- Bloated, painful, rigid abdomen — could indicate organ complications or internal hemorrhage from an adrenal tumor
- Drinking and urinating excessively that worsens despite treatment — dose may be inadequate, or a comorbidity like diabetes may have developed
For suspected poisoning or medication overdose, contact ASPCA Animal Poison Control at (888) 426-4435 (24/7, consultation fee applies) or the Pet Poison Helpline at (855) 764-7661.
Ongoing Treatment Costs: What to Budget
Cushing's disease is a chronic condition requiring lifelong management. Here's a realistic cost breakdown so you can plan financially:
| Expense Category | First Year | Ongoing Annual Cost |
|---|---|---|
| Initial diagnostic workup | $800–$2,500 | N/A |
| Trilostane medication (Vetoryl®) | $500–$1,800/year | $500–$1,800/year |
| Monitoring blood work (ACTH stim + chemistry panels) | $600–$1,200 (more frequent in year 1) | $400–$800 (2–4 rechecks/year) |
| UTI treatment (if recurrent) | $100–$400 | $100–$400 |
| Emergency visits (Addisonian crisis, complications) | $500–$2,500 (if applicable) | $500–$2,500 (if applicable) |
| Total estimated range | $2,500–$8,400 | $1,500–$5,500/year |
Pet insurance can offset a significant portion of these costs, provided the policy was purchased before diagnosis (Cushing's is considered a pre-existing condition once diagnosed). If you have a predisposed breed, consider enrolling in a comprehensive insurance plan during puppyhood or early adulthood. Policies with annual limits of $10,000–$30,000 typically cover Cushing's management well.
Frequently Asked Questions About Cushing's Disease in Dogs
Is Cushing's disease painful for dogs?
Cushing's itself is not typically painful in the way an injury or infection is. However, the secondary effects can cause discomfort: muscle weakness makes movement difficult, calcinosis cutis can cause skin irritation and itching, and complications like UTIs or bladder stones are painful. Most dogs with well-managed Cushing's appear comfortable and maintain a good quality of life.
Can diet cure or reverse Cushing's disease?
No. There is no diet, supplement, or holistic remedy that can cure Cushing's disease. While proper nutrition supports overall health and can help manage some symptoms (like elevated triglycerides), the underlying hormonal dysregulation requires medical or surgical treatment. Be cautious of products or protocols claiming to "naturally cure" Cushing's — they are not supported by veterinary evidence.
How quickly do symptoms improve after starting treatment?
Most owners notice reduced thirst and urination within 1–3 weeks of starting trilostane. Appetite typically normalizes within 2–4 weeks. Coat regrowth is the slowest change — expect 3–6 months before you see significant hair returning, and in some dogs, the coat never fully returns to its pre-disease state.
Can Cushing's disease cause diabetes in dogs?
Yes. Excess cortisol antagonizes insulin action, and approximately 5–10% of dogs with Cushing's disease also develop diabetes mellitus. When both conditions are present, diabetes is often difficult to regulate until the Cushing's is controlled. In some cases, treating the Cushing's resolves the diabetes.
Should I euthanize my dog if diagnosed with Cushing's?
A Cushing's diagnosis alone is not a reason for euthanasia. Most dogs with pituitary-dependent Cushing's respond well to medication and enjoy good quality of life for 2–5+ years. Euthanasia may be considered in cases of malignant adrenal tumors with metastasis, severe neurological decline from a macroadenoma that doesn't respond to radiation, or when the financial burden of ongoing care is unsustainable for the owner. This is always a personal decision made with your veterinarian's guidance.
Is Cushing's disease in dogs contagious?
No. Cushing's disease is not contagious and cannot be transmitted to other dogs, pets, or humans. It is an internal endocrine disorder with no infectious component.
What happens if Cushing's disease is left untreated?
Without treatment, Cushing's disease progressively worsens. Over time, the immune suppression leads to recurrent and severe infections, muscle wasting becomes debilitating, and the risk of life-threatening complications increases — particularly pulmonary thromboembolism (blood clots in the lungs), severe pancreatitis, and kidney damage. Most untreated dogs survive 1–2 years after clinical signs become apparent, though quality of life declines significantly in the later stages.
Dr. Hannah Wickes
All our authors care for dogs every day — read more of their work on the authors page.
