Cushing Disease and Dogs: Symptoms, Diagnosis & Treatment Guide

If your dog has been drinking noticeably more water, losing patches of fur, or developing a rounded "pot-bellied" appearance, you may be facing a diagnosis of Cushing's disease — medically known as hyperadrenocorticism. This endocrine disorder occurs when a dog's body produces excessive amounts of cortisol, the stress hormone normally regulated by the adrenal and pituitary glands. According to the Merck Veterinary Manual, Cushing's disease affects approximately 1 to 2 out of every 1,000 dogs per year, making it one of the most commonly diagnosed hormonal disorders in middle-aged and older dogs. Roughly 80–85% of cases are pituitary-dependent (PDH), caused by a small tumor on the pituitary gland, while 15–20% are adrenal-dependent (ADH), originating from a tumor on one or both adrenal glands. A third form, iatrogenic Cushing's, results from prolonged use of steroid medications like prednisone.

What Is Cushing's Disease in Dogs?

Cortisol is essential for life — it helps regulate metabolism, manage stress responses, reduce inflammation, and maintain blood pressure. But when cortisol levels remain chronically elevated, the result is a cascade of systemic problems that can affect nearly every organ in your dog's body. The hypothalamic-pituitary-adrenal (HPA) axis normally keeps cortisol production in check through a feedback loop. In Cushing's disease, this feedback mechanism breaks down.

Breeds Most Prone to Cushing's Disease

Research published in the Journal of Veterinary Internal Medicine and data compiled by the American Kennel Club identify the following breeds as having elevated risk:

Breed	Primary Type	Notes
Poodle (Miniature & Standard)	PDH	Among the highest reported prevalence
Dachshund	PDH	Small body size can make symptom onset more noticeable
Yorkshire Terrier	PDH	Common in geriatric populations
German Shepherd	PDH / ADH	Higher-than-average adrenal tumor incidence
Golden Retriever	PDH	Large breed; watch for muscle wasting
Beagle	PDH	Frequently cited in endocrine research cohorts
Boston Terrier	PDH	Brachycephalic breeds may have compounded respiratory issues
Boxer	PDH / ADH	Adrenal tumors reported at higher rates

While these breeds show statistical predisposition, any dog — mixed breeds included — can develop Cushing's disease. If your dog fits the age and breed profile and is showing symptoms, it warrants a veterinary conversation.

Recognizing the Symptoms of Cushing's Disease

Cushing's disease is often called a "slow-onset" condition because early symptoms can be subtle and easily attributed to normal aging. Many owners don't realize something is wrong until the disease has progressed significantly. The following checklist organizes symptoms by how they typically present over the disease timeline.

Early Warning Signs (Often Overlooked)	Advanced / Progressive Symptoms	Emergency Red Flags
Increased thirst (polydipsia) — drinking 2–3× normal water volume Increased urination (polyuria) — more frequent potty breaks, possible house accidents Increased appetite (polyphagia) — begging, scavenging, weight gain despite activity Mild panting more than usual Slightly thinning coat along the trunk	Pronounced "pot-bellied" abdomen from muscle wasting and liver enlargement (hepatomegaly) Bilateral symmetrical hair loss (alopecia) on trunk, sparing head and legs Darkened, thickened skin patches (hyperpigmentation, calcinosis cutis) Visible muscle wasting, especially in the thighs and temples Recurrent skin infections and slow wound healing Recurrent urinary tract infections (UTIs) Lethargy and reduced exercise tolerance Females: cessation of heat cycles; Males: testicular atrophy	Sudden collapse or inability to stand Seizures or disorientation (possible pituitary macroadenoma) Acute vomiting and diarrhea with weakness Rapid, labored breathing Blood in urine or stool Sudden blindness (retinal detachment from severe hypertension)

A useful rule of thumb: if your senior dog is drinking more than 100 mL of water per kilogram of body weight per day (roughly 45 mL per pound), that's clinically significant polydipsia and warrants investigation. For a 30 lb (13.6 kg) dog, that's more than about 1,360 mL — roughly 5.75 cups of water daily.

How Veterinarians Diagnose Cushing's Disease

Diagnosing Cushing's disease is one of the more complex workups in veterinary endocrinology. No single test is perfect, and your veterinarian will typically run a series of screening and confirmatory tests. Here's the typical diagnostic pathway you can expect.

Expect the full diagnostic workup (Steps 1–5) to cost between $700 and $1,500 at a general practice. If referral to a veterinary internist or advanced imaging is needed, total diagnostic costs can reach $2,000–$4,500.

Treatment Options for Cushing's Disease in Dogs

The appropriate treatment depends on whether your dog has pituitary-dependent or adrenal-dependent Cushing's, the size and behavior of any tumor, your dog's overall health, and your budget. Here's a comparison of the primary approaches.

Appropriate only when medication risks outweigh benefits. Requires close monitoring for progression.

Treatment	Type Used For	Mechanism	Success Rate	Estimated Monthly Cost	Key Considerations
Trilostane (Vetoryl®)	PDH & ADH	Inhibits cortisol synthesis in adrenal glands	85–93% show clinical improvement within 2–4 weeks	$40–$150/month (dose-dependent; ~1–3 mg/kg twice daily)	FDA-approved for dogs. Requires regular ACTH stim monitoring. Must be given with food. First-line treatment for most cases.
Mitotane (Lysodren®)	PDH & ADH	Selectively destroys adrenal cortex cells	80–90% response rate during induction phase	$20–$80/month (after initial loading phase)	Older drug, less commonly used now. Requires careful induction phase monitoring. Risk of Addisonian crisis if overdosed.
Adrenalectomy (Surgical)	ADH (benign adenoma)	Removal of the affected adrenal gland	Curative in ~85% of benign ADH cases; perioperative mortality 5–10%	$3,000–$7,000 one-time (surgery + hospitalization)	Requires experienced surgeon. Not appropriate for malignant adrenal carcinomas with invasion. Post-op cortisol supplementation needed temporarily.
Hypophysectomy	PDH (select cases)	Surgical removal of the pituitary gland	Long-term remission in ~70–80% of cases at specialized centers	$5,000–$10,000+ one-time	Available at only a handful of veterinary institutions (e.g., UC Davis, University of Utrecht-trained surgeons). Requires lifelong thyroid and cortisol supplementation post-surgery.
Radiation Therapy	PDH with macroadenoma	Shrinks pituitary tumor causing neurological signs	Improves neurological symptoms in ~75% of cases; does not normalize cortisol alone	$4,000–$8,000 (full course)	Usually combined with trilostane for cortisol control. Multiple sessions over 3–4 weeks.
Supportive / Watchful Waiting	Mild PDH, very elderly or comorbid dogs	Manage symptoms without targeting cortisol directly	Variable; does not slow disease progression	$20–$60/month (supplements, UTI management)

Important: Your veterinarian will determine the correct medication, dosage, and monitoring schedule for your dog. Never adjust trilostane or mitotane doses without veterinary guidance — both under-treatment and over-treatment carry serious risks.

Prognosis and Life Expectancy

Cushing's disease is generally a manageable chronic condition rather than a death sentence — but prognosis varies significantly depending on the type, tumor behavior, and how early treatment begins.

Scenario	Median Survival Time (with treatment)	Quality of Life Outlook
PDH with microadenoma (tumor <10 mm), treated with trilostane	2–2.5 years (many dogs live 3–5+ years)	Excellent — most symptoms resolve or improve significantly within 2–3 months
PDH with macroadenoma (>10 mm), no neurological signs	1.5–2 years with medical management	Good to fair — monitoring for tumor growth essential
PDH with macroadenoma and neurological signs	6–12 months without radiation; improved with radiation + trilostane	Fair to guarded — depends on response to radiation
ADH — benign adenoma, surgically removed	Curative; normal life expectancy if surgery is successful	Excellent after recovery
ADH — malignant adrenal carcinoma	6–18 months (high metastatic rate to liver, lungs)	Guarded — depends on staging and response to treatment
Iatrogenic Cushing's (steroid-induced)	Variable — depends on underlying condition requiring steroids	Often reversible with gradual steroid taper under veterinary supervision

According to a large retrospective study published in the Journal of Small Animal Practice, dogs with PDH treated with trilostane had a median survival of approximately 900 days (roughly 2.5 years) from diagnosis, with many dogs living well beyond that timeframe. Dogs that die within the first few months of diagnosis typically succumb to unrelated conditions (kidney disease, cancer, heart disease) rather than Cushing's itself.

Daily Home Care and Long-Term Management

Managing Cushing's disease is a long-term commitment. Here's what daily and ongoing care looks like for a dog on treatment:

Medication Administration

• Trilostane must be given with food (fat helps absorption) — typically twice daily at 12-hour intervals. Consistency in timing and meal composition matters for stable cortisol levels.
• Keep a medication log: date, time, dose given, and any observed side effects (vomiting, lethargy, diarrhea, loss of appetite).
• Never skip doses without consulting your vet, but also never double up if you miss a dose.

Monitoring Schedule

• Week 2: First ACTH stimulation test after starting trilostane
• Week 4: Second ACTH stim test and electrolyte panel (checking for hyperkalemia — elevated potassium, a sign of over-suppression)
• Week 12: Third monitoring check
• Every 3–6 months thereafter: Ongoing ACTH stim tests, chemistry panels, and clinical assessment
• Each monitoring visit typically costs $150–$350 (ACTH stim + blood work)

Lifestyle Adjustments

• Water access: Ensure constant access to fresh water. Increased thirst will gradually decrease as cortisol normalizes, but restricting water is dangerous.
• Potty schedule: Expect more frequent bathroom breaks initially. This should improve within 4–8 weeks of effective treatment.
• Diet: Feed a balanced, moderate-fat, moderate-protein diet. Avoid high-sodium foods. Some veterinarians recommend prescription diets formulated for endocrine support, but a high-quality commercial diet meeting ASPCA nutritional guidelines is appropriate for most dogs.
• Skin care: Use gentle, moisturizing shampoos for thinning skin. Watch for secondary bacterial or yeast infections, which are common in Cushingoid dogs due to immune suppression.
• Exercise: Maintain moderate, consistent exercise. Avoid sudden increases in intensity, as muscle wasting makes dogs more prone to injury.

Signs of Over-Treatment (Addisonian Crisis)

Both trilostane and mitotane can push cortisol too low, causing an acute adrenal insufficiency crisis. This is a veterinary emergency. Watch for:

• Sudden vomiting or diarrhea
• Extreme lethargy or collapse
• Loss of appetite lasting more than 24 hours
• Shaking, trembling, or weakness

If you observe these signs, stop the medication and contact your veterinarian or emergency clinic immediately.

The Real Cost of Treating Cushing's Disease

Budgeting for Cushing's disease requires understanding both the initial investment and the ongoing monthly and annual costs. Here's a realistic breakdown based on 2026 veterinary pricing across the United States:

Cost Category	Low Estimate	Mid Estimate	High Estimate	Frequency
Initial diagnostic workup (blood work, LDDST, ACTH stim, ultrasound)	$700	$1,100	$1,500	One-time
Advanced imaging (CT/MRI) if needed	$1,200	$2,000	$3,500	One-time (if required)
Trilostane (Vetoryl) monthly	$40	$85	$150	Monthly
Monitoring visits (ACTH stim + blood work)	$150	$250	$350	4× in Year 1; 2–3× annually after
UTI treatment (recurrent infections are common)	$50	$100	$200	Per episode; 2–4× per year typical
Skin infection treatment	$40	$80	$150	Per episode
Emergency visit (Addisonian crisis)	$500	$1,200	$3,000+	As needed

First-year total estimate: $2,500–$5,000+ depending on diagnostic complexity and any complications.
Ongoing annual cost (Years 2+): $1,500–$3,000/year for medication, monitoring, and incidental care.

Pet insurance can significantly offset these costs if your dog was enrolled before diagnosis. Most comprehensive plans cover 70–90% of eligible expenses after deductible. However, Cushing's disease diagnosed before enrollment will be classified as a pre-existing condition and excluded by virtually all insurers.

When to See the Vet Immediately

For non-emergency concerns — new symptoms, medication side effects, or questions about dose adjustments — schedule a regular appointment with your veterinarian. Always consult your veterinarian before making any changes to your dog's treatment plan.

Can Cushing's Disease Be Prevented?

The pituitary and adrenal tumors that cause naturally occurring Cushing's disease cannot be prevented — they arise spontaneously and have no known environmental trigger you can control. However, there are steps you can take to reduce risk and catch the disease early:

• Minimize unnecessary steroid use: If your dog is prescribed prednisone or similar corticosteroids for allergies, itching, or inflammation, discuss the lowest effective dose and shortest duration with your vet. Ask about steroid-sparing alternatives such as oclacitinib (Apoquel®), lokivetmab (Cytopoint®), or allergen-specific immunotherapy.
• Annual senior blood work: For dogs over 7 years old, annual blood panels can catch early metabolic changes (rising ALP, mild hyperglycemia) before clinical symptoms become obvious.
• Track water intake: Keep a rough log of how much water your dog drinks. A sudden increase is one of the earliest reliable indicators.
• Know your breed's risk: If you own a predisposed breed, mention Cushing's disease screening during routine wellness visits once your dog reaches 7–8 years of age.

Frequently Asked Questions About Cushing's Disease in Dogs

Disclaimer: This article is for informational purposes only and does not replace professional veterinary advice. Always consult your veterinarian for diagnosis, treatment decisions, and medication management for your dog. If you suspect your dog has ingested a toxic substance, contact the ASPCA Animal Poison Control Center at (888) 426-4435 (24/7, consultation fee applies) or the Pet Poison Helpline at (855) 764-7661.