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
Understanding supports better veterinary conversations.
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.
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.
Which animals can be affected?
Risk factors, examination findings and management can 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.
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?
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.
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 emergency veterinary care if you notice:
SEEK EMERGENCY VETERINARY 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.
Sources behind this guide
Cornell University: Cushing’s syndromePrimary veterinary or veterinary-university guidance ↗American Animal Hospital Association: diagnosing canine Cushing’sPrimary veterinary or veterinary-university guidance ↗American Animal Hospital Association: treatment and monitoringPrimary veterinary or veterinary-university guidance ↗Content last reviewed: August 30, 2026. Review status: veterinary-informed; independent veterinarian review not yet completed.