Cushing’s disease, or hyperadrenocorticism, is a condition in which a dog’s body produces too much cortisol for too long. It usually shows up in middle-aged and older dogs, and the early signs look like ordinary aging: drinking and urinating more, a bigger appetite, a rounder belly, thinning fur and heavier panting. Testing is the only way to confirm it.
Why Cushing’s Hides Behind “He Is Just Getting Old”
Cushing’s rarely arrives overnight. It builds over months, sometimes over a year or more, and each change on its own has an innocent explanation. The water bowl empties faster, so you fill it twice a day instead of once. Your dog asks to go out at 5am, so you adjust your morning. The coat looks a little thinner, so you blame the season.
Because the changes are gradual, families adapt without noticing they are adapting. That is the real trap. The signal is not any single sign, it is the cluster appearing together and slowly getting more pronounced. Normal aging in dogs tends to look like slowing down. Cushing’s often looks like a dog who is somehow doing more: drinking more, eating more, panting more, while the body underneath is getting weaker.
If you have already noticed your older dog changing, our guide to senior dog and cat care in Dunbar is a useful companion read alongside this one.
The Sign Cluster That Warrants an Exam
None of the following confirms anything on its own, and this list is not a way to diagnose your dog at home. It is a prompt to book a proper exam so a veterinarian can look at the whole picture:
- Drinking and urinating more. Refilling the bowl noticeably more often, overnight accidents in a reliably house-trained dog, or larger puddles than usual.
- A ravenous appetite. Counter surfing, stealing food, or begging in a dog who was never food-driven before.
- A pot-bellied or sagging abdomen. Often paired with thinner-looking limbs and a topline that has lost muscle.
- Thinning coat and slow regrowth. Symmetrical hair loss over the flanks and trunk, thin skin, or fur that never grows back properly after a clip.
- Recurrent skin and urinary infections. Infections that keep returning once treatment stops, or a urinary infection with no obvious discomfort.
- Panting at rest. Heavy breathing on a cool evening, indoors, with no exercise behind it.
- Weakness and low stamina. Reluctance on stairs, needing help into the car, or cutting the usual neighbourhood walk short.
Two of these deserve a seasonal note on Vancouver’s West Side. Excess cortisol makes dogs less tolerant of heat, so a dog who used to handle a warm summer afternoon on Dunbar Street may now pant hard and tire quickly, and that combination should never be dismissed as simply a hot day. Through our long wet season, a damp coat sitting against thin, fragile skin makes recurring skin infections more likely and slower to settle. If itching and infection are the loudest problem you are seeing, our post on common causes of itching in dogs covers the wider list of possibilities.
Pituitary and Adrenal Forms, in Plain Terms
The adrenal glands sit near the kidneys and produce cortisol. The pituitary, a small gland at the base of the brain, tells them how much to make. Cushing’s develops when that system loses its brake.
In most affected dogs the problem starts in the pituitary, which sends a constant over-instruction to both adrenal glands. In a smaller share of dogs the problem starts in one adrenal gland itself. There is also a third route: dogs on long-term steroid medication for another condition can develop very similar signs. That is one reason your veterinary team will ask for a full medication history, and it is also why you should never stop or change a prescribed medication on your own. Talk to the clinic first.
The distinction matters because it shapes what happens next, from which tests are run to whether imaging of the glands is needed. It is not a detail your veterinarian can guess from signs alone.
Why Diagnosis Takes Staged Testing, Not One Blood Draw
Owners are often surprised that there is no single yes-or-no Cushing’s test. Cortisol naturally rises and falls through the day, and other illnesses can push it up temporarily, so one snapshot can mislead in either direction. Diagnosis is built in stages.
It usually starts with a physical exam and a careful history, then general bloodwork and a urine sample. That first round is largely about ruling out the conditions that mimic Cushing’s, including kidney disease, blood sugar disorders, thyroid problems and simple infection. If those results point toward excess cortisol, the next stage is specific adrenal function testing, which typically means timed samples collected over several hours rather than a single draw, so your dog may spend part of a day at the clinic. Imaging with ultrasound may follow to look at the adrenal glands directly.
Our pet diagnostics are run on site with digital X-ray, ultrasound and in-house laboratory testing, which shortens the wait between stages. Ongoing investigation and management sit under medical services, where long-term conditions and senior pet medicine are handled. If a dog is unwell or stressed at the time of testing, your veterinarian may deliberately postpone or repeat a step, which is a sign of careful medicine rather than delay. For context on why baseline results matter so much here, see why annual blood tests are important for pets.
What Long-Term Monitoring Actually Looks Like
Cushing’s is managed rather than cured, so the plan is a long-term one. Where medication is appropriate, dosing is set and adjusted by your veterinarian based on recheck testing, never by how the dog looks on a given day. Rechecks are usually frequent in the first stretch after starting treatment, then space out once things are stable.
Your part is observation. Many clinics ask owners to track measured water intake over a normal day, appetite, coat condition, energy and any accidents in the house, because those numbers often shift before bloodwork does. Bring that record to every recheck. Never adjust or pause medication at home, and call the clinic if your dog goes off food, vomits, becomes weak or seems suddenly flat. Bundling these visits into our pet wellness program keeps the schedule predictable, and anything that cannot wait for a scheduled recheck belongs with urgent care the same day.
Quality of Life and the Realistic Outlook
The goal of treatment is comfort and a normal routine, not a cure. Many dogs whose condition is well managed drink less, sleep better, regrow coat over several months and return to the walks they had been dropping out of. Response varies between individuals, and older dogs frequently have other conditions running alongside, which is why monitoring stays part of life rather than ending after the first good recheck.
Progress is measured in weeks and months, not days, and coat changes are usually the slowest to turn around. What matters most is that the everyday things get easier: the house stays dry overnight, breathing settles at rest, and your dog wants to come along again.
Common Questions from Dunbar Dog Owners
Is Cushing’s disease painful for my dog?
Cushing’s itself is not usually described as painful, but it does make dogs uncomfortable. Excess thirst, disrupted sleep, muscle weakness, thin skin and recurring infections all wear on daily comfort, and those effects are a legitimate reason to investigate rather than wait.
Which dogs are most likely to be affected?
It is most commonly recognized in middle-aged and older dogs, and some smaller breeds are over-represented. That said, it is diagnosed across a wide range of breeds and sizes, so age and sign cluster matter far more than breed when deciding whether to test.
My dog only drinks more water. Is that enough to test?
It is enough to book an exam. Increased thirst has several possible causes, including kidney disease and blood sugar disorders, so the first visit is about narrowing the field with an exam, bloodwork and a urine sample rather than jumping straight to adrenal testing.
Is this the same as the thyroid condition I have read about in cats?
No. Both are hormonal conditions, but they involve different glands, different species patterns and different testing. Our post on feline hyperthyroidism covers that one separately if you have a cat at home as well.
How long will testing and follow-up take?
Expect a staged process rather than one appointment. Initial screening can often happen in a single visit, specific adrenal testing usually takes several hours in hospital, and rechecks continue on a schedule your veterinarian sets. Your team will explain each step before it happens.
Concerned About Your Older Dog? Start With an Exam
If two or three of the signs above sound like your dog, the useful next step is simple: book an exam and bring your notes on water, appetite and energy. Our team on Dunbar Street can start the workup, run the laboratory and imaging stages here, and walk you through the results in plain language. Learn more about our medical services for dogs and cats.
Published by the team at Alta Vista Animal Hospital.
This article is educational content only and is not a substitute for an in-person veterinary exam, diagnosis or treatment. If your pet has an urgent concern, contact Alta Vista Animal Hospital during open hours or your nearest emergency veterinary hospital right away.
Alta Vista Animal Hospital
4543 Dunbar St, Vancouver, BC V6S 2G7, Canada
(604) 221-5858
Monday to Friday: 8 AM to 7 PM
Saturday: 8 AM to 6 PM
Sunday: 9 AM to 5 PM