Canine Dementia or Cognitive Dysfunction: Signs and How to Support the Brain

Canine dementia is being discussed more and more, yet it is still very easy to put changes in an older dog down to age alone. They sleep more, move more slowly, no longer react in quite the same way, sometimes become confused in familiar places or grow restless in the evenings. “He’s old” feels like a perfectly logical explanation. But not every age-related change means dementia, and dementia is not a normal or inevitable part of aging.

Canine cognitive dysfunction syndrome, or CCDS, is a chronic, progressive and age-related neurodegenerative syndrome that affects a dog’s behaviour and cognitive abilities.

The risk does increase with age. In a classic study, disturbances in at least one cognitive behavioural category were found in 28% of dogs aged 11–12 and 68% of dogs aged 15–16. The important nuance is that these figures refer to impairment in at least one behavioural category, not to a diagnosis of dementia in 68% of 15–16-year-old dogs.

Signs of canine dementia: what does DISHAA mean?

The acronym DISHAA is often used when assessing signs of canine cognitive dysfunction. Its advantage is simple: “he seems somehow different” becomes a set of concrete areas that an owner can actually observe.

• D, disorientation: the dog becomes lost in familiar places, gets “stuck” behind furniture or in corners, stares at walls for long periods or seems confused in a familiar environment.
• I, changes in social interaction: a previously social dog may withdraw, or the opposite may happen and the dog may seek more closeness than usual; irritability can also increase.
• S, sleep–wake cycle changes: the dog sleeps more during the day but wanders, vocalises or becomes restless at night.
• H, house-soiling and loss of learned behaviour: a previously house-trained dog begins toileting indoors or seems to forget previously learned commands and routines.
• A, activity changes: purposeful activity decreases, or repetitive aimless walking, circling or wandering appears.
• A, anxiety: restlessness, clinginess, fear of familiar situations or difficulty being left alone increases.

With CCDS, these changes usually appear gradually and become more pronounced over time. That is exactly why they can be difficult to notice at first.

The owner’s observations are extremely valuable here. Write down when the change began, whether it happens all the time or only in certain situations, and whether anything else changed at the same time. Short videos, sleep and activity data, and notes about house-soiling or anxiety may give a veterinarian far more useful information than simply saying, “he seems older lately.”

Diagnosing canine cognitive dysfunction: other causes should be ruled out first

A change in behaviour does not automatically mean cognitive dysfunction. Pain, arthritis, deteriorating vision or hearing, kidney and liver disease, urinary problems, neurological disease, tumours, seizures and medication effects can all cause very similar signs. Anxiety may also be related to chronic pain rather than directly to dementia.

Current approaches to CCDS emphasise medical history, assessment of progressive DISHAA changes, and physical, orthopaedic and neurological examination together with appropriate laboratory testing. It is also important to evaluate what happens after possible concurrent problems are treated. In more complex cases, brain MRI may be justified, particularly to rule out other structural neurological diseases.

This is especially important when a change appears suddenly. CCDS is a progressive condition. Severe disorientation, loss of balance, a seizure, a sudden behavioural change or another neurological sign that appears within a day calls for prompt assessment, not the assumption that “the dementia suddenly flared up.”

Can canine dementia be prevented or reversed?

At present, there is no single method, diet or supplement known to guarantee that a dog will not develop CCDS, and there is no proven method that simply reverses an established neurodegenerative disease. That does not mean, however, that nothing can be done.

Early recognition matters, and cognitive function and quality of life can be supported in several ways. The most sensible approach is usually not to search for one “brain supplement”, but to combine movement, cognitive and social enrichment, nutrition, pain management, good sleep and, when necessary, medication.

Movement, using the brain and social interaction

An aging dog still needs movement. The point is not that they should do the same things at the same intensity as at five years old, but that both body and brain continue to receive appropriate stimulation.

Walking at a suitable level, sniffing, simple search games, food puzzles, learning small new skills and social interaction can all help maintain physical and mental activity. Studies combining environmental enrichment and exercise with nutritional support have produced better results than using only one measure.

The individual dog still matters. If a dog has arthritis or another source of pain, the answer is not simply “more exercise”. Pain needs to be recognised and addressed first, after which a level of activity the body can tolerate can be found.

Routine also becomes increasingly important for a dog with CCDS. Familiar meal times, walks and sleeping places reduce the need to adapt constantly to a changing environment. Night lights may help with nighttime disorientation, and unnecessary rearranging of furniture and the dog’s resources at home is best avoided.

Nutrition and the aging brain

Brain health does not depend on one “brain supplement”. The foundation is a balanced diet, an appropriate energy intake, a healthy body condition and sufficient high-quality protein and fats.

In a 2025 systematic review, studies of enriched diets were generally methodologically stronger than studies of individual supplements. There is positive canine evidence for omega-3 fatty acids, MCTs and SAMe, but not every product marketed for “brain support” belongs in the same evidence category.

This is an important principle for supplements in general: a supplement is not a strategy. First we need to know what we are trying to support and why.

MCTs, or medium-chain triglycerides

MCTs are particularly interesting in cognitive health because they are converted into ketone bodies, which the aging brain can use as an alternative source of energy.

In a 2010 study, senior dogs were fed a diet containing 5.5% MCT for eight months, and dogs in the MCT group performed better than controls in several tasks assessing learning, spatial ability and attention.

A clinical study published in 2018 examined pet dogs already showing signs of cognitive dysfunction. Several DISHAA domains improved with a diet containing MCTs and multiple other brain-supportive nutrients. There is an important nuance, however: the study diet also contained DHA, EPA, B vitamins, antioxidants and arginine. The entire effect therefore cannot be attributed to MCTs alone.

MCT is not the same as coconut oil

MCT oil is often produced from coconut oil, but an MCT preparation and ordinary coconut oil do not have the same composition. Canine MCT studies therefore cannot automatically be treated as evidence that a particular amount of coconut oil will have the same effect.

That does not mean coconut oil is bad. It simply means we should not take the results from a study of one product and automatically transfer them to a different product.

Omega-3, especially DHA

EPA and DHA are important components of cell membranes, and omega-3 fatty acids are studied in the context of both inflammatory processes and brain aging.

A systematic review found signals of cognitive benefit from omega-3 in aging companion animals, but the products, doses and combinations used in the studies varied. This does not translate into “the more fish oil, the better”. The whole diet, the actual amount of EPA and DHA, product quality and the dog’s other diseases and medications all need to be considered.

I have written in more detail about nutrition, muscle mass, omega-3 and other important nutrients for older dogs in the article “Senior Dog Food: What Should Change in an Older Dog’s Bowl?”

SAMe

SAMe, or S-adenosylmethionine, is one of the supplements for which there is also a controlled study in dogs. A 2008 double-blind placebo-controlled study included 36 dogs over eight years of age with signs of age-related cognitive decline. Over two months, dogs in the SAMe group improved more than the placebo group, particularly in measures of activity and awareness.

It was still a relatively small study using a specific preparation, so it cannot be concluded that all SAMe products and all dogs will respond in the same way.

Lion’s Mane: interesting, but still too early for big promises in dogs

Lion’s Mane, or Hericium erinaceus, is one of the interesting integrative options being explored for brain health. Its bioactive compounds have been studied in relation to nerve growth factor, oxidative stress, inflammation and the gut–brain axis.

In a small placebo-controlled human study, cognitive scores improved in participants with mild cognitive impairment during 16 weeks of Lion’s Mane use, but declined again after supplementation was stopped. The study included only 30 people.

There is also a 2022 study in 18 senior dogs that received food containing Lion’s Mane for 16 weeks. Changes were observed in the composition of the gut microbiome, but cognitive function was not measured in that study. It therefore cannot be used to claim that Lion’s Mane improves dementia in dogs.

For now, Lion’s Mane belongs more in the category of “interesting and worth studying” than “proven CCDS treatment in dogs”.

The gut, inflammation, stress and the aging brain

The brain does not operate separately from the rest of the body. Oxidative stress, neuroinflammation, changes in brain energy use and mitochondrial function are among the mechanisms being studied in CCDS. The gut–brain axis is also a justified area of research.

The fact that chronic inflammation, metabolism and the gut may affect brain health does not mean that every case of cognitive dysfunction is caused by “leaky gut”, toxins or a single food ingredient. A biologically plausible mechanism and a proven clinical cause are not the same thing.

Reducing stress, ensuring adequate sleep, supporting good digestion, maintaining a healthy body weight, providing a varied diet and reducing unnecessary environmental burdens are sensible goals for an aging dog in any case. They should not, however, be sold as a miracle cure for dementia.

Vaccination and immune-system load

In integrative veterinary medicine, the possible relationship between vaccination and canine cognitive dysfunction is sometimes discussed as one potential part of the overall environmental and immune burden. At present, however, there are not enough canine studies to state that routine vaccination causes CCDS or that stopping vaccination prevents dementia.

That does not mean vaccination frequency or an individual dog’s response are irrelevant. International vaccination guidelines also emphasise that vaccines should not be given more often than necessary, and that the need for non-core vaccines should be assessed according to lifestyle, infection risk, age and health status. Immunity to core vaccines may persist for years, and adult dogs are not generally recommended to be automatically revaccinated against them every year.

With my own dogs, I have seen a noticeable improvement in their general health since I stopped routine vaccination. That is my personal experience and does not prove a causal relationship between vaccines and cognitive dysfunction, but it is one reason why I prefer vaccination decisions to be individual rather than an automatic calendar event.

The broader question of chronic inflammation is also relevant to cognitive health. Activated microglial cells and other changes associated with neuroinflammation have been found in the brains of dogs with CCDS. This makes the role of the immune system and inflammation in brain aging a very interesting area of research, but these findings do not currently tell us what proportion, if any, might be attributable to vaccines or other environmental factors.

Heavy metals, aluminium and detox

Integrative veterinary medicine also sometimes considers the possible role of heavy metals and other environmental toxins in neurological problems and chronic inflammation. It is a subject worth researching, but there is currently insufficient canine evidence to claim that heavy metals or vaccine adjuvants are a primary cause of CCDS, or that a general “heavy metal detox” can reverse cognitive dysfunction.

That does not mean detoxification is meaningless or that supporting the body’s natural elimination processes has no value at all.

Suspected true heavy-metal poisoning is, of course, a genuine medical issue. In that situation, a dog needs appropriate diagnostics and specific treatment, not simply the assumption that neurological signs automatically mean “toxin burden”.

Questions raised in integrative care about the environment, inflammation and toxic exposures do not need to be thrown away. A hypothesis, however, should remain a hypothesis until there is enough evidence to call it something more.

What else can a veterinarian do?

Once other possible causes have been assessed and CCDS is considered likely, a veterinarian may discuss nutritional support, pain and anxiety management and more specific treatment options depending on the individual dog.

Selegiline is one of the medications used to treat canine cognitive dysfunction. Supporting a dog with CCDS is not only about medication, however. Depending on the dog, the best overall plan may combine medication, nutrition, environmental enrichment, movement and treatment of concurrent problems such as pain and anxiety.

Integrative methods, such as herbal medicine or acupuncture, may form part of a supportive plan for some dogs, but the evidence is not currently as strong as it is for all of the approaches discussed above. Suitability depends on the individual dog and any medications being used.

The most important thing is to notice change

The older a dog becomes, the more valuable the owner’s ability to notice small trends becomes.

Is the dog suddenly sleeping more? Is nighttime restlessness increasing? Do they stop in places where they never used to stop? Have they started toileting indoors? Are they avoiding touch because they no longer recognise you, or because they are in pain?

One symptom does not always give us the answer. A pattern tells us much more.

That is why it is worth writing observations down when living with an older dog rather than waiting until the change has become very obvious. Supporting CCDS is probably most effective when we begin supporting the brain and the whole dog before the problem has progressed too far.

In summary

Canine cognitive dysfunction is not simply “he’s old”. It is a genuine neurodegenerative syndrome, but many other treatable problems can look very similar. The first step is therefore to notice the changes and investigate their cause, not to jump straight to a dementia diagnosis.

We cannot promise that the right food, fish oil, MCT, Lion’s Mane or any other supplement will definitely prevent dementia. There is, however, growing evidence that movement, cognitive and social enrichment, appropriate nutrition and certain targeted nutritional interventions may support the aging dog’s brain and quality of life. The evidence for enriched diets, MCTs, omega-3 and SAMe is currently stronger than that for many other popular “brain supplements”.

My own principle remains the same here as with the rest of canine health: science helps us understand what may generally work, but careful observation of our own dog helps us understand what is happening to that individual. And the earlier we notice that something has changed, the more opportunities we have to support them.

You can also use a cognitive-dysfunction questionnaire to help assess whether your pet may be showing signs of dementia.