Understanding Cushing's Disease in Dogs

If you’ve noticed changes in your dog like excessive drinking, a rounder belly, or thinning hair, you’re probably wondering what’s going on. These can be signs of Cushing’s disease, a condition that mostly affects middle-aged and senior dogs. Understanding what it is, what to look for, and how to manage it can help you take the best care of your pup.

What is Cushing’s disease and what causes it?

Cushing’s disease, or hyperadrenocorticism, happens when your dog’s body produces too much cortisol. Cortisol is the hormone that helps your dog manage stress, fight infections, and maintain a healthy weight, but when there’s too much of it for too long, it starts to cause serious problems throughout the body.

Cushing’s typically occurs in middle-aged to older dogs, and the disease develops slowly, meaning early signs aren’t always obvious. This makes it easy to chalk the changes up to normal aging, but it’s worth getting checked out.

There are three reasons this can happen:

• Pituitary-dependent Cushing’s (PDH): A tumor on the pituitary gland (a small gland at the base of the brain) causes it to overproduce a hormone called ACTH, which then tells the adrenal glands to pump out more cortisol than the body needs. This is the most common form.
• Adrenal-dependent Cushing’s (ADH): A tumor on one of the adrenal glands (the small glands that sit above the kidneys) causes it to produce excess cortisol directly. The tumor can be benign or malignant, which affects treatment decisions.
• Iatrogenic Cushing’s: This type isn’t caused by a tumor at all. It develops when a dog has been on corticosteroid medications for a long time, prescribed for another condition like allergies or immune disease. The good news is that it often resolves once the steroids are slowly tapered off under your vet’s supervision.

Certain breeds are more predisposed than others including Poodles, Dachshunds, Boxers, Beagles, and Boston Terriers.

Signs and symptoms of Cushing’s

Because the signs of Cushing’s disease overlap with many other conditions, diagnosis usually requires multiple steps, and it can be easy to miss the early ones. You might spot:

• Increased thirst and urination: It may seem as though your dog’s thirst is never satisfied, and they may want to go out to urinate at all hours, or even start having accidents indoors.
• Increased appetite: Your dog could act hungrier than usual, even begging for food.
• A pot-bellied appearance: This develops because of an increase in fat within the abdominal organs, and because the muscles of the abdominal wall become weaker and eventually atrophy.
• Thinning or loss of hair: You may notice hair loss on the flanks, neck, and perineum, and the skin on the abdomen can take on a thin, crepey appearance.
• Lethargy and lack of energy: Dogs with Cushing’s might not be as playful or active as they used to be.
• Excessive panting: Even in cooler temperatures or without much activity.
• Recurrent skin or urinary infections: Too much cortisol weakens the immune system, leaving the body vulnerable to other diseases and infections.

Since it can take at least a year for symptoms to develop, and because they’re often mistaken for common signs of aging, many dogs have advanced Cushing’s by the time they’re diagnosed. If something feels off, trust your instincts and get it checked.

Left untreated, Cushing’s can lead to complications like diabetes, high blood pressure, blood clots, and more.

How is Cushing’s disease diagnosed?

Vets typically start with routine lab work, like blood tests and a urinalysis, to rule out more common diseases that can cause similar symptoms. From there, they may recommend specific tests like:

• ACTH stimulation test: A blood sample is taken before and after an injection of ACTH. ACTH is administered into the dog’s muscle, and one hour later blood is drawn again to measure cortisol levels. In dogs with Cushing’s disease, cortisol is increased in both samples.
• Low-dose dexamethasone suppression test: A drug called dexamethasone is administered and additional blood samples are collected after four and eight hours. Normally cortisol would be suppressed, but in dogs with Cushing’s disease, it remains elevated.
• Imaging: An abdominal ultrasound lets your vet see the adrenal glands and assess their size and whether a tumor is present.

If these tests reveal that your dog’s tumor is malignant, your vet will stage the cancer, a process that involves understanding the tumor type, size, and spread. Staging is vital for choosing the right treatment plan.

Should I treat my dog’s Cushing’s disease?

This is one of the first questions most owners ask, and it’s a fair one. Cushing’s is a lifelong condition, and treatment is a long-term commitment. But for most dogs, the answer is yes, and here’s why.

Untreated Cushing’s doesn’t just cause the symptoms listed above, over time, it increases the risk of serious complications like diabetes, high blood pressure, blood clots, and recurring infections. Treatment won’t cure the disease, but it can significantly reduce those risks and help your dog feel like themselves again.

Here’s what treatment typically looks like:

• Medication: Vetoryl (trilostane) is the only drug approved by the FDA to treat both pituitary- and adrenal-dependent Cushing’s in dogs. It works by stopping the production of cortisol in the adrenal glands. Frequent blood tests and vet checkups are usually required in the first few months after starting treatment, and then every few months after that depending on your dog’s response.
• Surgery: For adrenal-dependent Cushing’s, removing the affected adrenal gland can resolve the condition if the tumor is benign. Surgery and radiotherapy are complicated procedures available only at a few specialty centers, so medical treatment is often the most practical and approachable option.
• Iatrogenic resolution: If caused by steroids, your vet will taper the medication slowly to avoid withdrawal complications.

The decision to treat should always be made with your vet, taking into account your dog’s age, overall health, and quality of life. What’s most important is that you have that conversation, because for most dogs, treatment makes a real difference.

Is Cushing’s disease covered by pet insurance?

Yes, Cushing’s disease is covered under Lemonade Pet’s base accident and illness policy, as long as it isn’t pre-existing. That includes eligible costs like bloodwork, imaging, and the ongoing medication that’s typically central to managing the condition long-term.

Cushing’s requires ongoing management: regular vet visits, medication adjustments, and routine bloodwork to monitor how your dog is responding. Having coverage in place before any symptoms appear means that as the condition evolves, cost isn’t the thing driving your decisions.

Before we go

Cushing’s disease is a condition that rewards patience and consistency. It can take time to find the right medication dose, and regular monitoring is a real part of life with this diagnosis. But with the right management plan in place, most dogs do well and maintain a good quality of life. If you don’t have a pet insurance policy in place yet, it’s worth taking a few minutes to explore your options.

Getting a quote is straightforward, and having coverage before anything develops puts you in a much stronger position when it matters most.

Frequently Asked Questions

A few quick words, because we <3 our lawyers: This post is general in nature, and any statement in it doesn’t alter the terms, conditions, exclusions, or limitations of the policies issued, which differ according to your state of residence. You’re encouraged to discuss your specific circumstances with your own professional advisors. The purpose of this post is merely to provide you with info and insights you can use to make such discussions more productive! Naturally, all comments by, or references to, third parties represent their own views, and Lemonade assumes no responsibility for them. Coverage may not be available in all states. Please note that statements about coverages, policy management, claims processes, Giveback, and customer support apply to policies underwritten by Lemonade Insurance Company or Metromile Insurance Company, a Lemonade company, sold by Lemonade Insurance Agency, LLC.  The statements do not apply to policies underwritten by other carriers.