True cure of Cushing’s disease is only possible in a specific subset of dogs: those with an adrenal tumor that can be surgically removed before it spreads. For the 80% to 85% of dogs whose Cushing’s is caused by a pituitary tumor, the condition is typically managed rather than cured, usually with daily medication that controls symptoms and can give your dog years of good quality life. That distinction matters, because “management” in this case can look a lot like a cure from your dog’s perspective: the excessive thirst, pot belly, and skin problems resolve, and your dog feels like themselves again.
Why the Type of Cushing’s Determines the Path
Cushing’s disease happens when your dog’s body produces too much cortisol, the stress hormone. There are three ways this occurs, and each one has a different treatment outlook.
Pituitary-dependent (80–85% of cases): A small tumor on the pituitary gland at the base of the brain sends constant signals to the adrenal glands, telling them to pump out cortisol. Because the tumor sits deep inside the skull, it’s not easy to remove. Most dogs with this form are treated with medication for life.
Adrenal-dependent (15–20% of cases): A tumor grows directly on one of the adrenal glands and produces excess cortisol on its own. If that tumor hasn’t spread and can be surgically removed, this is the one scenario where a complete cure is realistic.
Iatrogenic (medication-induced): Some dogs develop Cushing’s symptoms after long-term use of steroid medications like prednisone. This form is reversible. Your vet will gradually taper the steroid dose over several weeks, switching to a shorter-acting steroid and stepping down the amount until your dog’s adrenal glands recover their ability to function normally. Periodic blood tests confirm when the medication can finally be stopped.
Surgery for Adrenal Tumors
Removing the affected adrenal gland (adrenalectomy) is the only widely accepted way to cure naturally occurring Cushing’s. In a study of 302 dogs that underwent the procedure, 87% survived to discharge, and the median survival time for tumor-related outcomes was nearly four years. That’s a meaningful stretch of life, especially considering most dogs are middle-aged or older at diagnosis.
The surgery does carry real risks. About 25% of dogs experienced postoperative complications, with pancreatitis (6%) and aspiration pneumonia (5%) being the most significant. Dogs that developed either of those complications had notably shorter survival times. Your vet will evaluate the tumor with imaging beforehand to check for spread to nearby blood vessels or organs, which can make surgery riskier or rule it out entirely. When surgery isn’t an option, adrenal tumors are managed with the same medications used for pituitary cases.
Surgery for Pituitary Tumors
A procedure called transsphenoidal hypophysectomy, where a surgeon accesses the pituitary gland through the roof of the mouth, does exist for dogs. It’s not widely available, limited to a small number of specialty centers worldwide, but the results are encouraging. In a recent study of 34 small dogs, complete tumor removal was achieved in 28 of them. Among dogs that reached full remission, the recurrence-free rate was 90% at both one and two years after surgery, with a median remission period of over three years.
Dogs that undergo this surgery lose their pituitary gland entirely, which means they’ll need lifelong hormone replacement therapy for thyroid function and other hormones the pituitary normally controls. It’s a serious commitment, but for the right candidate it can eliminate the disease rather than just manage it. If this interests you, ask your vet about referral to a center that performs the procedure.
Medical Management With Trilostane
For most dogs, daily medication is the primary treatment. Trilostane (sold as Vetoryl) is the only drug approved by the FDA to treat both pituitary and adrenal forms of Cushing’s. It works by blocking an enzyme the adrenal glands need to produce cortisol. The block is reversible and dose-dependent, which is actually a safety feature: if cortisol drops too low, stopping the drug lets levels recover.
Your vet will start with a dose based on your dog’s weight, typically given once or twice daily with food. The first few weeks involve close monitoring. Expect a recheck at 10 to 14 days after starting the medication, then again at 30 days. At each visit, a blood test measures how your dog’s cortisol responds to stimulation, usually performed 3 to 5 hours after the morning dose. Once the right dose is dialed in and your dog’s symptoms are improving, monitoring shifts to every 90 days.
Most owners notice changes within the first few weeks. The relentless thirst and frequent urination are usually the first symptoms to improve. The pot-bellied appearance, thinning hair, and skin changes take longer, sometimes a few months, because the body needs time to recover from prolonged cortisol exposure. Trilostane doesn’t eliminate the underlying tumor, so it’s a lifelong medication. But many dogs do very well on it. Median survival times for dogs with pituitary-dependent Cushing’s treated with trilostane range from about 662 to 900 days (roughly two to two and a half years) in referral settings, and some dogs live considerably longer.
Other Medication Options
A second FDA-approved drug, selegiline (sold as Anipryl), treats only certain pituitary-dependent cases. It works differently from trilostane, acting on brain chemistry rather than directly blocking cortisol production. It tends to be effective in a smaller proportion of dogs and is used less commonly.
Mitotane (Lysodren) is an older, off-label option that takes a more aggressive approach. Rather than simply blocking cortisol production, it actually destroys portions of the adrenal gland tissue. It requires a careful induction period, typically around 10 days of daily dosing, during which your vet monitors your dog closely for signs that cortisol has dropped enough. After induction, the drug is given at a lower weekly maintenance dose. The more aggressive “Utrecht” protocol intentionally destroys nearly all adrenal function, essentially creating the opposite condition (Addison’s disease), which is then managed with replacement hormones. Because of its potency and narrower safety margin, mitotane is generally reserved for cases where trilostane isn’t working or isn’t tolerated.
Radiation for Large Pituitary Tumors
Some pituitary tumors grow large enough to press on the brain, causing neurological symptoms like disorientation, circling, or seizures. Radiation therapy can shrink these tumors and relieve pressure. In a study of nine dogs treated with radiation, seven of eight dogs with neurological signs showed improvement during or immediately after treatment, and half experienced complete resolution of those signs.
There’s an important caveat: radiation reduces the tumor but doesn’t normalize cortisol levels. Dogs still need trilostane or another medication to control the hormonal excess. Radiation is best understood as a tool for managing the tumor itself, not the hormone problem it causes.
Diet and Day-to-Day Support
Cushing’s changes your dog’s metabolism. Excess cortisol promotes fat storage, muscle wasting, and can raise blood sugar. While no single diet works for every dog, a few principles help support treatment.
- Low fat: Less than 12% fat on a dry matter basis helps counteract the tendency to gain weight and develop high blood lipids.
- Moderate fiber: Roughly 8% to 17% crude fiber on a dry matter basis helps with blood sugar regulation and satiety.
- Highly digestible protein: Egg whites, chicken, beef, lamb, and organ meats help maintain muscle mass without overtaxing the body. Cushing’s dogs lose muscle, so quality protein matters.
Beyond diet, keeping your dog at a healthy weight through gentle, consistent exercise supports joint health and mood. Cushing’s dogs are prone to skin infections and urinary tract infections, so watch for new or recurring skin lesions, increased licking, or changes in urination beyond what’s typical for the disease.
What Long-Term Management Looks Like
Living with a Cushing’s dog on medication means committing to a routine: daily pills with food, quarterly vet visits with blood work, and staying alert to symptom changes. If your dog suddenly becomes lethargic, stops eating, or develops vomiting or diarrhea, cortisol may have dropped too low, a condition called hypoadrenocorticism. Your vet may run additional electrolyte checks or a stimulation test to evaluate this. Dose adjustments happen throughout the course of treatment as your dog’s needs shift.
In a primary care study of 219 dogs in England, dogs with pituitary-dependent Cushing’s had a median survival of 700 days from diagnosis, and those with adrenal-dependent Cushing’s survived a median of 596 days. These are median figures, meaning half of the dogs lived longer. With attentive management, many dogs maintain a comfortable, active life well beyond those benchmarks.