How to Manage Cushing's Disease in Dogs (Vet Reviewed Guide)

Cushing's disease (also called hyperadrenocorticism) happens when your dog's body produces too much cortisol over a prolonged period.

Cortisol is a normal, essential hormone made by the adrenal glands. It helps regulate your dog's stress response, metabolism, immune system, and blood pressure. The problem isn't cortisol itself — it's having too much of it, for too long.

In most cases, the cause is a small, usually benign tumour in the pituitary gland — a pea-sized gland at the base of the brain — that essentially tells the adrenal glands to keep producing cortisol when they shouldn't. 

Less commonly, a tumour on the adrenal gland itself is responsible. In some cases, long-term steroid medication can cause similar changes, which is known as iatrogenic Cushing's.

There are three possible causes of Cushing’s Disease, and your vet will have a good idea of which one applies to your dog as it shapes both the treatment plan and what to expect long term.

The most common cause is a tiny, benign growth on the pituitary gland. It's not dangerous in the way a cancer diagnosis would be, but it does cause the pituitary gland to send the wrong signals to the adrenal glands, telling them to keep pumping out cortisol when they shouldn't. This is called pituitary-dependent Cushing's.

Less commonly, a small growth on one of the adrenal glands themselves is the culprit — producing cortisol on its own, without being told to. This is adrenal-dependent Cushing's, and in some cases surgery to remove the affected gland can be curative.

There's also a third cause that's worth knowing about: if your dog has been on steroid medication long-term for another condition, this can sometimes trigger very similar changes in the body. The good news with this form is that it usually improves once the steroid is gradually reduced under your vet's supervision.

Cushing's develops slowly, often over months or even years. The body gradually adapts to rising cortisol levels, which is why the early signs are so easy to dismiss as your dog simply getting older.

If you've been wondering whether something was "off" with your dog for a while without being able to put your finger on it, that's very common with this condition.

Signs that often appear first include:

• Drinking and urinating much more than usual
• Eating more than normal
• Panting, even at rest or in cool temperatures
• A rounder, pot-bellied appearance
• Thinning coat or patchy hair loss
• Skin that seems fragile or prone to infections
• Tiring more quickly on walks

Excess cortisol breaks down muscle, redistributes body fat, weakens the skin, and suppresses parts of the immune system, which explains why so many different things seem to change at once.

Cushing's can't be confirmed with a standard blood test alone, which can feel frustrating when you're waiting for answers.

Routine blood tests may show some telling changes, particularly elevated liver enzymes, dilute urine, and raised cholesterol, but these aren't enough on their own to confirm the diagnosis. Specific hormonal tests are needed, most commonly:

• ACTH stimulation test — measures how the adrenal glands respond to stimulation
• Low-dose dexamethasone suppression test — assesses how cortisol is being regulated
• Abdominal ultrasound — used in some cases to look at the adrenal glands directly

Because cortisol levels fluctuate naturally, and stress can affect results, repeat testing is sometimes needed. It can feel like the process is taking longer than expected, but getting the diagnosis right before starting lifelong treatment is genuinely worth it.

Most dogs are treated with a daily medication called trilostane, which works by reducing the amount of cortisol the adrenal glands produce.

What to expect when starting treatment:

• Daily medication, usually given with food
• A recheck blood test 10–14 days after starting, to confirm the dose is right
• Ongoing monitoring every 3–6 months once stable

The goal of treatment isn't to eliminate cortisol entirely. Your dog still needs some. It's about bringing levels back into a healthy range, which is why careful dose adjustment matters, especially in the early weeks.

For dogs with an adrenal tumour rather than a pituitary cause, surgery may be an option, though this involves a referral.

Medical Treatment for Cushing's Disease

While understanding the condition and managing it at home plays an important role, many dogs will be prescribed a daily oral medication to bring cortisol levels back under control and relieve the symptoms that have been affecting their quality of life.

Medication works alongside regular monitoring, dietary adjustments, and attentive home care to give your dog the best possible outcome. The right treatment plan is individual to your dog, so don't hesitate to ask your vet questions about dosing, what to watch for at home, and how you'll know it's working.

If your vet has diagnosed your dog with Cushing’s Disease, you can read this technical guide on Trilostane for dogs to understand more about this medication.

Managing Cushing's is an ongoing process rather than a one-time fix, but for most owners, it becomes a straightforward routine.

Your dog will need regular ACTH stimulation tests to check cortisol levels are well controlled, along with electrolyte monitoring and general health checks. Your vet will also ask how your dog is doing day-to-day, since clinical signs are just as important as test results.

The good news is that most dogs show noticeable improvement within the first few weeks of treatment, particularly drinking less, urinating less, and panting less. Coat and skin improvements tend to take a little longer, often a few months.

Because trilostane reduces cortisol production, there's a small risk of levels dropping too low, particularly in the early stages of treatment or after a dose change. Contact your vet promptly if your dog develops:

• Sudden severe lethargy or weakness
• Vomiting in dogs or dog diarrhoea
• Loss of appetite
• Collapse

These signs can indicate that cortisol has dropped too low and needs to be addressed quickly. When in doubt, always call your vet.

Are there natural remedies for Cushing's disease in dogs? 
There are no proven natural remedies for Cushing's disease. Some supplements are marketed for adrenal support, but none have been shown to effectively reduce cortisol levels in the way that veterinary medication does. If you're concerned about medication side effects, speak to your vet — there may be options to adjust the approach, but stopping or replacing treatment without veterinary guidance isn't recommended.

How does diet affect Cushing's disease? 
Diet alone can't treat Cushing's, but a low-fat diet can help manage the high cholesterol and high triglyceride content often seen with Cushing's Disease. Discussing diet options with your vet is worthwhile, particularly if blood results show elevated lipid levels.

How often will my dog need vet appointments? 
Your dog will need more frequent appointments at first. Expect follow-up appointments around 10–14 days after starting medication, then at roughly 1, 3, and 6 months as the dose is stabilised. Once your dog is well controlled, monitoring intervals typically settle to every 3–6 months.

For most dogs, Cushing's disease is manageable rather than curable, but manageable is still a very good outcome.

With consistent treatment and regular monitoring, many dogs live for several years with genuinely good quality of life. Left untreated, excess cortisol raises the risk of high blood pressure, diabetes, blood clots, and recurring infections, so starting treatment makes a meaningful difference to long-term health, not just day-to-day comfort.

Cushing's is very much a condition you and your vet manage together. The more consistent the monitoring, the more straightforward it tends to be.

If your dog was recently diagnosed and you're feeling uncertain about what comes next, that's completely normal. Most owners find that once treatment is established and their dog starts to feel better, the ongoing management feels much more manageable than it did at the start.