Cushing's Disease in Dogs: Symptoms, Diagnosis, and Treatment Guide

Cushing's disease in dogs — medically known as hyperadrenocorticism — occurs when the body produces too much cortisol, a steroid hormone essential for stress response, metabolism, and immune function. Left unchecked, chronic cortisol excess damages nearly every organ system. According to the Merck Veterinary Manual, approximately 1 to 2 out of every 1,000 dogs are diagnosed annually, making it one of the most common endocrine disorders in middle-aged and older dogs. Roughly 80–85% of cases originate from a pituitary gland tumor (pituitary-dependent hyperadrenocorticism, or PDH), while 15–20% stem from an adrenal gland tumor (adrenal-dependent hyperadrenocorticism, or ADH). A third form, iatrogenic Cushing's, results from prolonged use of corticosteroid medications like prednisone.

If your dog is drinking noticeably more water, losing hair in symmetrical patches, or developing a rounded "pot-bellied" abdomen, this guide will help you understand what may be happening, what your veterinarian will do, and what life looks like after diagnosis.

What Is Cushing's Disease in Dogs?

Cortisol is produced by the adrenal glands — two small organs sitting above the kidneys. In a healthy dog, the pituitary gland at the base of the brain releases adrenocorticotropic hormone (ACTH), which signals the adrenal glands to produce cortisol. When cortisol levels are sufficient, the pituitary reduces ACTH output. This feedback loop keeps hormone levels balanced.

In Cushing's disease, this loop breaks down:

• Pituitary-dependent (PDH): A small, usually benign tumor on the pituitary gland overproduces ACTH, constantly stimulating the adrenal glands. Both adrenal glands enlarge and pump out excess cortisol.
• Adrenal-dependent (ADH): A tumor on one adrenal gland autonomously produces cortisol, independent of pituitary signals. The other adrenal gland typically shrinks from disuse. About 50% of adrenal tumors are malignant (adrenal carcinoma); the rest are benign adenomas.
• Iatrogenic: Long-term administration of steroid medications (prednisone, dexamethasone, methylprednisolone) for allergies, autoimmune disease, or other conditions mimics Cushing's by flooding the body with exogenous cortisol.

The disease progresses slowly. Many owners don't notice changes until the condition is well-established, which is why understanding the symptom timeline matters.

Recognizing the Symptoms of Cushing's Disease

Because cortisol affects metabolism, immune function, skin integrity, and muscle maintenance, Cushing's produces a wide constellation of signs. Not every dog shows every symptom, and early signs are easy to dismiss as normal aging.

Symptom Checklist: Early Warning Signs vs. Advanced Indicators

Severity	Symptom	What You'll Notice
Early	Increased thirst (polydipsia)	Water bowl emptied more frequently; dog drinks 2–3× normal volume
Early	Increased urination (polyuria)	More frequent outdoor trips; possible house accidents in previously reliable dogs
Early	Increased appetite (polyphagia)	Dog begs constantly, scavenges, acts hungry even after meals
Early	Panting more than usual	Heavy breathing without exercise or heat exposure
Moderate	Hair loss (alopecia)	Symmetrical thinning on flanks, belly, and thighs; head and legs usually spared
Moderate	Pot-bellied appearance	Abdomen looks distended or rounded due to muscle weakness and fat redistribution
Moderate	Muscle wasting	Thinning legs, visible spine/ribs despite weight gain in torso
Moderate	Thin, fragile skin	Skin tears easily; visible bruising; slow wound healing
Moderate	Recurring skin infections	Hot spots, bacterial or yeast infections that keep returning
Advanced	Lethargy and weakness	Reluctance to exercise, climb stairs, or jump; general sluggishness
Advanced	Calcium deposits (calcinosis cutis)	Hard, gritty patches on the skin, especially along the back and shoulders
Advanced	Neurological signs	Disorientation, head pressing, circling, seizures (from a large pituitary macroadenoma)
Advanced	Recurrent urinary tract infections	Frequent UTIs due to immunosuppression; may be asymptomatic
Advanced	Hypertension	High blood pressure, detected during veterinary exam

The classic "textbook" presentation is a middle-aged dog with a ravenous appetite, constant thirst, thinning coat, and a sagging belly. But individual dogs may show only two or three of these signs, which is why diagnostic testing — not symptom guessing — is essential.

Risk Factors: Which Dogs Are Most Vulnerable?

According to the American Kennel Club, Miniature Poodles carry one of the highest breed-specific risks. If your dog fits the risk profile above and shows even two or three early symptoms, a veterinary workup is warranted.

How Is Cushing's Disease Diagnosed?

Diagnosing Cushing's is notoriously tricky. No single test provides a definitive answer in every case, and stress, illness, and certain medications can produce false positives. Your veterinarian will typically follow a staged diagnostic process:

Step 1: Screening Blood Work and Urinalysis

A complete blood count (CBC), serum chemistry panel, and urinalysis establish a baseline. Common findings that raise suspicion include elevated alkaline phosphatase (ALP), elevated cholesterol, stress leukogram (high neutrophils, low lymphocytes/eosinophils), and dilute urine (low specific gravity). These findings alone don't confirm Cushing's but justify further testing.

Estimated cost: $150–$300 for CBC, chemistry, and urinalysis.

Step 2: Confirmatory Hormone Tests

Two primary tests confirm or rule out the disease:

• Low-Dose Dexamethasone Suppression Test (LDDST): Blood is drawn, a small dose of dexamethasone is injected, and blood is re-drawn at 4 and 8 hours. In a healthy dog, dexamethasone suppresses cortisol production. In a dog with Cushing's, cortisol remains elevated. This test is considered the gold standard for initial confirmation, with a sensitivity of approximately 95% for PDH. Cost: $150–$250.
• ACTH Stimulation Test: Synthetic ACTH is injected, and cortisol is measured before and 1 hour after. An exaggerated cortisol response supports a Cushing's diagnosis. This test is less sensitive for PDH (roughly 80%) but is more specific and is essential for diagnosing iatrogenic Cushing's and monitoring treatment. Cost: $150–$250.

Step 3: Differentiating PDH from ADH

Once Cushing's is confirmed, your vet needs to know which type it is, because treatment differs significantly:

• High-Dose Dexamethasone Suppression Test (HDDST): A higher dexamethasone dose suppresses cortisol in most PDH cases but not in adrenal tumors. Cost: $150–$200.
• Endogenous ACTH level: A single blood draw measuring the dog's natural ACTH. High levels suggest PDH; low or undetectable levels point to an adrenal tumor. Cost: $80–$150, but the sample must be handled carefully (frozen, shipped to a reference lab).
• Abdominal ultrasound: Visualizes the adrenal glands. Symmetrically enlarged adrenals suggest PDH; one enlarged and one shrunken adrenal suggests ADH. Also detects adrenal tumor invasion into nearby blood vessels. Cost: $300–$600.

Step 4: Advanced Imaging (When Needed)

If a pituitary macroadenoma (tumor >10 mm) is suspected — usually because of neurological symptoms — an MRI or CT scan of the brain may be recommended. This is more common in veterinary specialty centers.

MRI/CT cost: $1,500–$3,000 at a referral hospital.

Treatment Options for Cushing's Disease in Dogs

Can Cushing's disease in dogs be cured? The answer depends on the type. Adrenal tumors can sometimes be surgically cured. Pituitary-dependent Cushing's is typically managed long-term with medication — not cured, but controlled. Here's a comparison of the main options:

Treatment Comparison: Medications, Surgery, and Supportive Care

Treatment	Best For	Mechanism	Success Rate	Monthly Cost (2026)
Trilostane (Vetoryl®)	PDH and ADH (first-line)	Inhibits cortisol synthesis in adrenal glands	85–93% of dogs show clinical improvement within 4–8 weeks	$50–$200 depending on dog size and dose
Mitotane (Lysodren®)	PDH (older protocol)	Selectively destroys adrenal cortex cells	80–90% achieve control; requires careful induction phase	$30–$120
Adrenalectomy (surgical removal)	Benign adrenal tumors (ADH)	Removes the tumor-bearing adrenal gland	Cure rate ~85% for benign tumors; perioperative mortality 5–10%	$2,500–$5,000 (one-time surgical cost)
Radiation therapy	Pituitary macroadenomas causing neurological signs	Shrinks pituitary tumor, relieves brain compression	Improves neurological signs in 70–80% of cases; does not normalize cortisol alone	$3,000–$6,000 (one-time course)
Supportive care	All cases alongside primary treatment	Manages secondary issues: UTIs, skin infections, hypertension, diabetes	Varies by complication	$30–$150 additional per month

Trilostane (Vetoryl®) — The Current Standard of Care

Trilostane is an FDA-approved medication specifically for canine Cushing's and is the most commonly prescribed option in 2026. It works by blocking the enzyme 3-beta-hydroxysteroid dehydrogenase, which the adrenal glands need to produce cortisol. It's given once or twice daily with food.

Typical starting dose: 1–2 mg/kg once daily, adjusted based on follow-up ACTH stimulation tests. Your vet will recheck at 10–14 days, 30 days, 90 days, and then every 3–6 months. Never adjust the dose without veterinary guidance.

Side effects: Most dogs tolerate trilostane well. Possible adverse reactions include vomiting, diarrhea, lethargy, and reduced appetite. Rarely, an Addisonian crisis (acute cortisol deficiency) can occur, which is a medical emergency requiring immediate veterinary attention.

Mitotane (Lysodren®) — The Older Alternative

Mitotane has been used since the 1970s and works by selectively destroying the cortisol-producing layer of the adrenal cortex. Treatment involves an initial "loading phase" (daily dosing for 5–10 days while monitoring for reduced water intake and appetite), followed by a maintenance phase (dosing 2–3 times per week). While effective, the loading phase carries a higher risk of an Addisonian reaction compared to trilostane, and many veterinarians now prefer trilostane as first-line therapy.

Surgery for Adrenal Tumors

If your dog has an adrenal tumor that hasn't invaded the caudal vena cava or metastasized, surgical removal (adrenalectomy) can be curative. This is a complex procedure best performed by a board-certified veterinary surgeon. Dogs need careful perioperative management including IV fluids, glucocorticoid supplementation, and monitoring for blood clots, hemorrhage, and pancreatitis. Post-surgery, the remaining adrenal gland may need weeks to months to resume normal cortisol production, during which the dog requires temporary steroid supplementation.

Iatrogenic Cushing's: Tapering Off Steroids

If your dog's Cushing's is caused by long-term corticosteroid use, the treatment is a gradual, veterinarian-supervised taper of the medication. Never stop steroids abruptly — this can trigger an Addisonian crisis because the adrenal glands have atrophied and cannot immediately resume cortisol production. The taper may take weeks to months, and some symptoms resolve gradually as the drug is withdrawn.

Prognosis and Life Expectancy

What is the life expectancy of a dog with Cushing's disease? With proper treatment and monitoring, many dogs live a near-normal lifespan. The prognosis depends heavily on the type, stage at diagnosis, and presence of complications:

Prognosis by Type and Stage

Condition	Median Survival Time	Key Factors
PDH, well-managed with trilostane	2–2.5 years from diagnosis (many live 3–5+ years)	Most dogs die from unrelated causes (cancer, kidney disease, heart disease) rather than Cushing's itself
PDH with pituitary macroadenoma (>10 mm)	6–18 months without radiation; improved with radiation	Neurological signs worsen as tumor grows; radiation can stabilize
ADH, benign tumor, surgically removed	2–4+ years; potentially normal lifespan	Best prognosis if surgery is successful and no complications
ADH, malignant tumor (carcinoma)	6–18 months with surgery; shorter without	Metastasis to liver or lungs significantly reduces survival
Iatrogenic Cushing's	Full recovery expected after proper taper	Depends on the underlying condition that required steroids

These numbers are medians from veterinary oncology and endocrinology literature. Individual outcomes vary widely. Many pituitary-dependent dogs on trilostane remain well-controlled for 4–6 years or more, particularly when diagnosed early and monitored consistently.

Home Care, Monitoring, and Daily Management

Managing Cushing's disease is a long-term commitment. Here's what daily life looks like for most treated dogs:

Medication Administration

Trilostane should be given with food to improve absorption. Consistency matters — give it at the same time(s) each day. If you miss a dose, give it when you remember unless it's close to the next scheduled dose. Never double up. Store capsules in their original container at room temperature, away from moisture.

Monitoring at Home

Track these indicators daily or weekly:

• Water intake: Measure how much water your dog drinks per day. A return to normal thirst is one of the first signs treatment is working. A sudden spike may indicate under-dosing or disease progression.
• Appetite: A dramatic drop in appetite can signal over-treatment (cortisol too low). Report this to your vet promptly.
• Energy level: Note changes in activity willingness, playfulness, and alertness.
• Coat and skin: Hair regrowth may take 3–6 months after cortisol levels normalize. Photograph your dog monthly to document changes.
• Urination patterns: Persistent accidents or straining may indicate a UTI, which is common in Cushing's dogs due to immunosuppression.

Veterinary Follow-Up Schedule

After starting trilostane or mitotane, expect this recheck schedule:

• 10–14 days: ACTH stimulation test, chemistry panel
• 30 days: ACTH stimulation test, chemistry panel
• 90 days: Full recheck including ACTH stim, CBC, chemistry, urinalysis, blood pressure
• Every 3–6 months thereafter: Ongoing monitoring for the dog's lifetime

Each recheck visit typically costs $150–$350 depending on the tests performed.

Lifestyle Adjustments

• Easy access to water and outdoor potty breaks: Even with treatment, some dogs continue to drink and urinate more than average. Never restrict water.
• Gentle exercise: Muscle weakness improves gradually with treatment. Short, frequent walks are better than long, strenuous outings, especially early in treatment.
• Skin care: Dogs with calcinosis cutis or thin skin may need medicated shampoos or topical treatments. Ask your vet about chlorhexidine-based shampoos for recurring bacterial skin infections.
• Weight management: As cortisol normalizes, your dog's metabolism will change. Work with your vet to adjust calorie intake and prevent obesity.

When to See the Vet Immediately

How Much Does Cushing's Disease Treatment Cost?

Budgeting for Cushing's disease requires planning for both upfront diagnostics and ongoing management. Here's a realistic cost breakdown based on 2026 U.S. veterinary pricing:

Cushing's Disease Cost Breakdown

Expense Category	Year 1 (Diagnosis + Treatment Start)	Ongoing Annual Cost
Initial diagnostics (blood work, LDDST, ultrasound)	$600–$1,500	$0
Advanced imaging (MRI if macroadenoma suspected)	$1,500–$3,000	$0 (unless repeat needed)
Trilostane (Vetoryl®) medication	$600–$2,400	$600–$2,400
Monitoring visits (ACTH stim + blood work)	$600–$1,200 (4–6 visits first year)	$300–$700 (2 visits/year)
Secondary issue management (UTIs, skin infections)	$100–$500	$100–$400
Surgery (adrenalectomy, if applicable)	$2,500–$5,000	$0
Total estimated range	$2,000–$13,600	$1,000–$3,500/year

Pet insurance can offset a significant portion of these costs if your dog was enrolled before diagnosis. Most comprehensive policies cover diagnostic testing, medication, and monitoring for endocrine disorders. Check whether your policy has annual or lifetime payout caps that could be reached with a chronic condition like Cushing's.

Frequently Asked Questions

Can Cushing's disease in dogs be prevented?

Pituitary and adrenal tumors cannot be prevented — they arise spontaneously with no known environmental trigger. However, iatrogenic Cushing's is preventable by using corticosteroid medications judiciously. If your dog requires long-term steroids for allergies or immune conditions, ask your veterinarian about steroid-sparing alternatives such as oclacitinib (Apoquel®), lokivetmab (Cytopoint®), or immunotherapy. When steroids are necessary, the goal should always be the lowest effective dose for the shortest duration.

Is Cushing's disease in dogs painful?

Cushing's itself isn't typically painful, but its complications can cause significant discomfort. Recurring skin infections are itchy and irritating. Muscle weakness makes movement difficult. Calcified skin deposits (calcinosis cutis) can be tender. Urinary tract infections cause burning during urination. Large pituitary tumors can cause headaches and neurological distress. Treating the underlying cortisol excess usually resolves most of these secondary issues.

What happens if Cushing's disease is left untreated?

Without treatment, excess cortisol progressively damages the body. Dogs develop worsening muscle wasting, severe skin fragility, recurrent infections, high blood pressure, and an increased risk of diabetes mellitus, pancreatitis, and blood clots. The immune system becomes dangerously suppressed. Most untreated dogs experience a steadily declining quality of life over 1–3 years, though the timeline varies. Some dogs with mild PDH remain stable for longer periods, but the disease does not resolve on its own.

Can I give my dog natural supplements instead of medication?

There is no peer-reviewed evidence that supplements such as melatonin, lignans, ashwagandha, or milk thistle can control Cushing's disease or normalize cortisol levels. Some supplements may support general liver health or coat quality as adjuncts, but they should never replace trilostane or mitotane. Discuss any supplements with your veterinarian before adding them, as some can interact with prescription medications.

Will my dog's hair grow back after treatment?

In most cases, yes — but slowly. Hair regrowth typically begins 2–4 months after cortisol levels normalize and may take 6–12 months for full coat recovery. Some dogs, particularly those with long-standing disease, may have permanent thinning. Calcified skin deposits may also take months to resolve or may leave permanent scarring.

Which breeds are most prone to Cushing's disease?

Breeds with documented predisposition include Miniature and Toy Poodles, Dachshunds, Boston Terriers, Yorkshire Terriers, Cairn Terriers, German Shepherds, Beagles, Cocker Spaniels, and Bichon Frises. However, any breed can develop Cushing's, and mixed-breed dogs are commonly affected as well.

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).