DOGS · OWNER EDUCATION
Cushing’s Disease: Too Much Cortisol
An easy-to-understand dog-owner guide to increased thirst, hunger, panting and coat changes, hormone testing, treatment and safe monitoring.
THE SHORT VERSION
What matters for your animal?
Start with the warning signs and when-to-contact sections if your animal is unwell. The same outward change can have several causes, so this guide helps you prepare questions rather than identify a diagnosis on your own.
What is this condition?
Cortisol helps the body use energy and respond to stress. Cushing’s syndrome, also called hyperadrenocorticism, means the body has too much cortisol activity over time. Addison’s is different: too little cortisol. These guides focus on dogs; do not apply their treatment plans to another species.
Cushing's disease involves excessive cortisol activity, which can affect thirst, appetite, skin, muscle, and other systems. These signs overlap with several illnesses. Testing establishes whether the pattern fits the disorder and what form is present. Treatment monitoring is essential because reducing cortisol too far can also cause serious illness; the correct plan cannot be judged from improved thirst alone.
Hormones are chemical signals that help coordinate functions such as energy use, stress responses, water balance, and reproduction. A shortage or excess may affect several body systems at once, which is why a hormone disorder can resemble other illnesses. Routine bloodwork may show effects of the disorder without confirming its cause. More specific testing may be needed, and illness or medication can influence some results. Monitoring follows both how the animal feels and what the appropriate tests show.
Which species does this guide cover?
The species listed above are the focus of this guide, rather than a complete list of every animal that can develop this condition. Causes, testing and treatment may differ between species and individual patients.
Why can it happen?
- Most naturally occurring cases begin with a usually benign growth in the pituitary gland, a small hormone-control gland near the brain. It sends too many signals to the adrenal glands beside the kidneys.
- An adrenal tumor can also produce excess cortisol. Some are benign and others are cancerous; the word ‘tumor’ alone does not tell you which.
- Prolonged exposure to steroid medication can cause a similar syndrome. Tell the veterinarian about tablets, injections, creams, and ear or eye medicines. Middle-aged and older dogs are most often affected.
What might an owner notice?
- More water-bowl refills, larger amounts of urine or new accidents indoors.
- Increased hunger or panting, a rounder belly, weaker muscles, thinning hair or fragile skin.
- Changes often develop gradually. Do not dismiss them as aging, but remember that diabetes and other diseases can look similar.
How is the problem investigated?
The veterinarian combines the history and examination with bloodwork and urine testing. A raised liver enzyme alone does not diagnose Cushing’s. A low-dose dexamethasone suppression test uses timed blood samples to check whether a medicine appropriately turns cortisol production down. Other tests may be needed. An adrenocorticotropic hormone (ACTH) stimulation test checks the adrenal response to a hormone signal. Ultrasound and other testing can help investigate the cause. Illness, stress and medicines can affect results. The veterinarian may first treat another illness or repeat testing; this is not simply a yes/no result from routine bloodwork.
Blood-cell testing and a chemistry profile provide complementary information. Cell counts can help assess anemia, inflammation, and platelets; chemistry measurements help assess organs and internal balance. Results are interpreted against the species, examination, hydration, medication history, and previous values. A value just outside the reference interval is not automatically the cause of illness. Trends can be more useful than one result, particularly when the aim is to monitor a chronic problem or check that treatment remains safe.
Blood glucose changes with food intake, stress, medication, and illness. One measurement is a snapshot, while a series of measurements or other monitoring methods can show how the pattern changes over time. The interpretation also depends on the species and the treatment being used. High glucose and dangerously low glucose require different responses. Keep the written instructions for missed meals, dose problems, and signs of illness available; never use a single unexpected reading to improvise a medication change.
Similar-looking skin changes can arise from parasites, infection, allergy, injury, or another underlying problem. Sampling the affected area can help separate those possibilities. Depending on the lesion, the veterinarian may examine cells, take scrapings, culture organisms, or obtain tissue for a pathologist. The purpose is to identify what is driving the damage, not just describe the redness or hair loss. Previous creams, cleaners, and medications are worth reporting because they can change the appearance and sometimes the usefulness of samples.
What might treatment involve?
Trilostane reduces cortisol production and is a common treatment. It requires repeat examinations and carefully timed tests; controlling symptoms must not push cortisol too low. Surgery may be appropriate for an adrenal tumor. Selected pituitary cases may need specialist surgery or radiation. Treatment choice depends on the cause, other illness and the dog’s quality of life. Medication-induced disease needs a veterinarian-directed steroid plan, not abrupt withdrawal.
This is an overview, not a prescription or a recommendation for a specific individual animal.
What can owners do at home?
Record thirst, appetite, urination, panting and energy. Bring the medication list and timing of the last dose to rechecks. Keep water freely available and offer extra toilet breaks. Ask the clinic exactly how to handle medication and food on testing days. Ask: What improvement should I expect? When is the next test? Who should I call if my dog becomes unwell?
A feeding plan should account for the actual food eaten, not just the amount offered. Selective eating, dropped food, hidden leftovers, and competition can make intake difficult to judge. Record the food type, measured portion, treats, and any supplements so the team can assess the complete diet. A disease-specific diet or assisted feeding may be recommended in some cases, but force-feeding is not a safe default for an animal that cannot swallow normally or may have an obstruction.
Avoid actions that could make care less safe.
- Do not restrict water to prevent accidents or adjust treatment based on thirst alone.
- If a dog taking trilostane becomes unwell, withhold it and contact the prescribing veterinarian promptly before another dose. Weakness, vomiting, diarrhea or loss of appetite can signal dangerously low cortisol.
- Do not abruptly stop long-term steroid medication or use ‘adrenal support’ supplements in place of prescribed care.
What can the longer-term outlook involve?
Many dogs gain better comfort and daily function with treatment. Outlook depends on the cause, complications and other health problems; medication often controls the disease rather than removing its cause.
A recheck is not simply a repeat of the first appointment. It assesses whether the original problem is improving, whether complications are appearing, and whether the treatment remains appropriate. The useful measures may include comfort, function, intake, body weight, examination findings, or selected tests. Ask which changes are expected before the visit and which should trigger an earlier call. Improvement in one sign does not always mean that every part of the disease has resolved.
Can risk be reduced?
There is no reliable way to prevent most naturally occurring cases. Careful prescribing and follow-up help reduce medication-related problems.
When should you arrange care?
- Arrange an appointment for persistent thirst, urinary accidents, panting or coat changes.
- Contact the clinic promptly for any new illness during treatment; do not wait for the scheduled recheck.
Seek urgent veterinary advice if you notice:
DO NOT DELAY URGENT CARE- Collapse, inability to stand, trouble breathing or rapidly worsening weakness.
- Repeated vomiting or diarrhea with marked weakness, especially during cortisol-lowering treatment. Seek emergency care rather than assuming this is routine Cushing’s.
What information helps the care team?
Write down when changes started, what makes them better or worse, actual food and water intake, and all medicines and supplements. Short videos and a medication-label photo can help describe changes that may not appear during the appointment.
How should you understand the tests?
Ask what each proposed test is intended to answer. Some tests identify a cause; others assess severity, organ function or treatment safety. Results are interpreted with the examination and history. A normal result does not exclude every problem, and an abnormal result does not always explain every sign.
Questions to ask before leaving
- What is confirmed, and which other explanations are still being considered?
- What changes should we expect with the proposed plan, and when should we reassess if they do not occur?
- Which observations should I record, and which changes mean I should call sooner?
- What medicine or home-care problems should I report, and what are the instructions for a missed dose or suspected side effect?
- When is the recheck, what will it assess, and whom should I contact after hours?
A care plan may be adjusted as results or the response become clearer. Keep the written instructions and tell the team if cost, handling or administration difficulty makes the plan hard to follow.
Sources behind this guide
Cornell University: Cushing’s syndromeVeterinary, university or animal-health guidance ↗American Animal Hospital Association: diagnosing canine Cushing’sVeterinary, university or animal-health guidance ↗American Animal Hospital Association: treatment and monitoringVeterinary, university or animal-health guidance ↗Content last reviewed: August 30, 2026. Review status: veterinary-informed; independent veterinarian review not yet completed.