Arizona scientists create a test that spots the first signs of dog dementia at 7–8 years old — years before obvious symptoms

What Arizona came up with

On 26 October 2026 the scientific journal Animal Cognition published a paper by researchers at the University of Arizona. They have developed CANID, a name that stands for a cognitive assessment of neuropsychological impairment in dogs. The test takes about 40 minutes and consists of three simple game-like tasks with treats. The work was led by psychology doctoral student Stephanie Hargrave, with Evan MacLean, a professor at the College of Veterinary Medicine, as senior author.

The key feature of CANID is that it detects subtle changes in brain function in dogs at around 7–8 years old, long before any obvious signs of dementia appear. Those signs usually only become noticeable by 12–14 years.

How the test works: three games

You cannot ask a dog whether its memory is good or whether it finds it easy to concentrate. So the scientists turned the assessment into games in which the dog gets a treat for the right answer.

We can't ask them questions, and we can't say, 'OK, this is a memory test.'

Evan MacLean, professor at the University of Arizona

1. Clear tube. A treat sits inside a transparent tube. The dog can see it, but if it pokes its nose against the side it can't reach it. It has to go round the tube and take the treat from the open end. This task tests the ability to hold back the first impulse, which dogs find harder with age.
2. Hidden treat. A treat is hidden behind one of four wooden screens. The dog has to remember where it is and find it after a delay of up to 40 seconds, sometimes after being distracted.
3. Detour round a barrier. The dog goes round a barrier to reach food. Once it has learned the open route, that route is quietly blocked and another one opened. The task tests flexibility — the ability to drop a familiar solution and find a new one.

The results of all three tasks are combined into an overall score.

What 239 dogs showed

The test was taken by 239 dogs in Tucson and California, many of them again after six months and after a year. Results were stable on repeat testing, at a level comparable to neuropsychological tests for people. That matters: it means the test measures lasting features of brain function rather than how a dog happens to feel on a particular day. For any medical test this is one of the main requirements: if the result jumps around from one time to the next, it cannot be trusted. Repeat tests after six months and a year also make it possible to see how a dog changes over time.

The scientists also found that brain function declines along the same path in dogs of different breeds. This means the same test works for a Chihuahua and a Labrador alike, and results can be compared across breeds.

Why early detection matters so much

At the moment dog dementia is usually picked up through questionnaires for owners. They are good at spotting obvious problems, but often only when the impairment is already serious.

As Stephanie Hargrave explains, by the time questionnaires finally show canine cognitive dysfunction syndrome, the problems are usually already marked and the window for early help has passed.

The earlier changes are noticed, the more time there is to try to slow them: adjust exercise, diet and routine, and discuss supportive treatment with the vet. For science, an early test opens up the chance to study what keeps the brain healthy in large groups of ordinary pet dogs. For example, testing whether particular diets, training or medicines really slow age-related changes — which requires precise measurements long before a dog starts getting lost at home.

What dementia in dogs is

Vets call it canine cognitive dysfunction syndrome. It is an age-related decline in brain function, similar to dementia in people. The signs are easiest to remember in a few groups:

• disorientation — the dog gets "stuck" in a corner or behind a door, doesn't recognise familiar places, stares at the wall;
• changes in interaction — less interest in its owners and in play, or the opposite: clinginess and irritability;
• sleep problems — restlessness and wandering at night, sleeping during the day;
• forgotten habits — "accidents" indoors in a dog that has been house-trained for years, poorer response to familiar commands;
• changes in activity — aimless walking, listlessness or, on the contrary, restlessness;
• anxiety — new fears, howling, barking for no reason.

Many owners put this down to "just old age", although some of the changes can be eased. The earlier you start, the better the result.

Why small dogs are more likely to live long enough for dementia

The researchers point out an interesting detail: large dogs often don't live to the age at which dementia becomes noticeable, so it is seen more often in small breeds such as Chihuahuas. It isn't that a small dog's brain is weaker, but that it lives longer and has time to reach this stage.

The link with Alzheimer's disease

Dogs with dementia can develop amyloid plaques in the brain — protein deposits similar to those seen in people with Alzheimer's disease. That is why research into canine ageing is also of interest to human medicine.

Dogs drink the same water we do, and they breathe the same air.

Evan MacLean

Dogs live alongside people and in the same environment, but they age much faster. By studying them, scientists hope to understand more quickly what affects the health of the ageing brain — in animals and in people.

Can the test be done at home?

Not yet. CANID needs trained staff and special equipment, so owners can't carry it out themselves. But simple observations are open to everyone. Notice whether your dog finds a hidden toy as quickly as before, whether it easily gets round an obstacle on a familiar route and whether it remembers commands. This won't replace the test, but it will help you spot changes in time and tell your vet about them. People living in the Tucson area can sign their dogs up for the lab's studies, and owners in other US states can join the Dog Aging Project, which involves around 50,000 dogs and the University of Arizona.

Creating CANID is an important milestone for us.

Evan MacLean

What this means for Europe

The CANID test is not yet available in European clinics, but the problem itself is well known here too. Dogs in Europe are living longer and longer, and vets are seeing more and more older patients with signs of dementia. European scientists also study ageing in dogs — for example at Eötvös Loránd University in Budapest, which has long worked with senior dogs.

The practical takeaway for owners in the UK and Europe is not to wait for obvious problems. From around 7–8 years, especially in small and medium breeds, it's worth discussing your dog's behaviour with your vet once a year — sleep, orientation, interaction and habits. Many practices use questionnaires for this, and answering them regularly helps spot changes earlier. If you would like to contribute to science, find out whether dogs are being recruited for ageing studies in the UK: such projects run at various universities, and taking part is usually free for owners.

How to support an ageing dog's brain

Scientists don't yet know a reliable way to prevent dementia, but plenty helps keep the mind sharp for longer:

• new experiences — walks on different routes, sniffing, getting to know new places;
• brain games — snuffle mats, puzzle feeders, learning new commands even in old age;
• exercise — regular walks suited to your dog's strength;
• nutrition — senior diets with antioxidants and beneficial fats, chosen together with your vet;
• routine — a predictable daily schedule, a night light if your dog is unsettled in the dark;
• overall health — treating pain and sight and hearing problems, which make disorientation worse.

In some countries there are also medicines your vet can prescribe for dementia, but it is always worth starting with lifestyle.

When to see your vet

If an older dog has started getting lost in the house, no longer recognises its owners, wanders at night or suddenly starts having accidents indoors, take it to the vet. Similar signs can be caused by other conditions — from kidney and thyroid problems to pain and brain tumours — and these need to be ruled out.

What happens next

The Arizona lab will go on studying how dogs' brains change with age and what protects them from decline. If the test proves its worth, similar tools may in time reach ordinary clinics. For now, the most important thing owners can do is watch their dog closely and give its brain something to do every day. A few minutes of searching for treats or learning a new trick is a simple habit that makes a dog happy at any age.