Dementia in dogs: what does it look like?

2 March 2023 - 6 min read
Illustration of a white dog on a blue background with a question mark representing a dog with dementia

Some health problems become more likely as dogs get older. One of the most common and devastating is canine cognitive dysfunction syndrome, which many people refer to as dog dementia.

Anybody caring for an older dog should familiarise themselves with the basics of this condition so they know when help is needed and how to get it.

This guide will answer your questions about dog dementia.

What is dog dementia?

The NHS says that dementia is "a syndrome (a group of related symptoms) associated with an ongoing decline of brain functioning”. We can apply this definition to dogs as well.

Dementia is not a specific disease but an umbrella term that describes the effects of several different health problems. The most common disease that causes symptoms of dementia in dogs is cognitive dysfunction syndrome, but any condition that has a significant effect on the brain’s ability to “think, remember, and reason” can lead to dementia.

This includes cancer, infections, inflammation, cerebrovascular disease, metabolic disorders, and inherited conditions that affect the brain.

A high percentage of dogs over the age of 11 have canine cognitive dysfunction syndrome, and it can even start earlier (sometimes around 8-9 years of age). In one study of 180 dogs, 28% of 11-to-12-year-old dogs and 68% of 15-to-16-year-old dogs had at least one symptom of cognitive dysfunction.

Unfortunately, we don’t know what causes cognitive dysfunction syndrome in dogs. It's a degenerative disorder affecting the brain, and a combination of factors most likely plays a role. These might include:

  • Age-related reduction in the amount of brain tissue your dog has

  • Changes in neurotransmitter levels that occur as dogs get older

  • An accumulation of abnormal proteins (beta-amyloid and tau) within the brain

  • Decreased blood flow within the brain

  • Infections affecting the brain

  • Direct major trauma causing death or damage to the brain

Watch our video below to learn more:

Can dog dementia be prevented?

Since the causes of dementia aren’t fully understood, it’s hard to give specific advice about what pet parents can do to prevent it. Our best option is to do everything we can to promote overall brain health.

The brain has an amazing ability to compensate for shortcomings and to form workarounds, so the healthier your dog is as they age, the longer the symptoms of dementia can be delayed or perhaps avoided altogether. Here are some things you can do that may help:

  • Feed your dog a healthy, balanced diet with the right amount of vitamins and minerals (ask your vet if you're unsure)

  • Keep your dog slim, as being overweight can cause negative health effects

  • Provide daily exercise opportunities

  • Offer lots of mental stimulation — teach them new tricks, use food puzzles, explore new environments, and meet new people and pets

  • Stay current on preventative health care, including veterinary check-ups and dental care

How to diagnose dog dementia

In the past, people have written off dog dementia as “normal” signs of ageing. We now know that this isn’t the case.

The acronym DISHAAL is a useful tool for remembering the signs of cognitive dysfunction in dogs. The acronym breaks down the clinical signs of canine cognitive dysfunction into seven categories:

  • Disorientation: Wandering aimlessly, staring blankly, and moving to or getting stuck in unusual places can be signs of disorientation in dogs.

  • Interaction Abnormalities: Dogs with dementia may become more withdrawn and not interact with people or other pets like they used to. They may have reduced responsiveness and become irritable or even aggressive to people or other pets in the home.

  • Sleep-Wake Cycle Disturbances: Dogs will often wake frequently and become active and vocal throughout the night. They may sleep more during the day, and it can become harder to wake your dog up. Your dog may wake and whine at night, like they've had nightmares or vivid dreams.

  • House Soiling: Dogs who have been potty-trained for years often start having accidents in the house.

  • Activity Changes: Cognitive dysfunction can make some dogs lethargic. Conversely, other dogs spend a lot of time pacing, wandering, or developing repetitive behaviours. They may lose interest in eating.

  • Anxiety: Anxiety can infuse all of the other symptoms of dementia. Dogs may whine, bark, pant, pace or become destructive.

  • Learning/Memory Changes: Dogs with dementia may forget previously learned tricks or commands and have difficulty learning new things.

Initially, dogs tend to develop just one or two of these symptoms, which may be quite mild at the start. Over time, a dog’s clinical signs can worsen, and more will likely develop. Dog dementia treatment is at its most effective when it's started early, so make an appointment with your veterinarian if you think your dog might be developing signs of cognitive dysfunction syndrome.

If you can, take a video of any abnormal behaviours your dog has at home and show it to your vet. Dogs can suppress their symptoms when they’re in a new environment surrounded by people they don’t know very well.

When presented with a dog who might have cognitive dysfunction syndrome, veterinarians will first look for evidence of underlying health problems like metabolic diseases or a brain tumour. Some conditions, like losing sight in the eyes, can present similarly to cognitive decline, so it's important your vet can work out the exact cause of the problem before creating a plan to help your dog cope with their condition.

The diagnostic process will start with some questions about what you are seeing at home, a physical examination, and a neurologic examination, probably followed by a diagnostic test that includes a complete blood cell count, biochemistry profile, and urinalysis.

To confirm the diagnosis, the vet may also do further tests such as blood pressure measurements or advanced imaging tools like an MRI to see if your dog’s dementia symptoms are due to cognitive dysfunction syndrome or another health problem.

How can I care for a dog with dementia?

While there is no cure for cognitive dysfunction syndrome in dogs, it's possible to manage symptoms and help them live the longest, happiest life possible.


Selegiline (Anipryl) is a medication that increases dopamine levels (a neurotransmitter) in the brain. You shouldn’t use it with some other medications like certain antidepressants or amitraz, so make sure your veterinarian knows everything that your dog is taking, including flea and worm treatments. It can take 3 to 6 weeks for a dog to fully respond to selegiline.

Levetiracetam (Keppra), a drug medical professionals prescribe to treat seizures, may also reduce symptoms associated with cognitive dysfunction syndrome. Propentofylline, which is licensed for use in the UK, increases blood flow in the brain and has been shown to help some dogs with dementia.

Supplements and diet

Studies have found that s-adenosylmethionine (SAMe) can improve clinical signs associated with cognitive dysfunction. Medium-chain triglycerides (MCT) provide an alternative energy source for the brain, so are considered a good supplement for dogs in early cognitive decline.

Anecdotal evidence indicates that melatonin, valerian root, dog-appeasing pheromone, phosphatidylserine, ginkgo biloba, and apoaequorin may also be beneficial, but no large studies have yet been done on their usefulness in dogs at this time to confirm this anecdotal evidence.

Dog foods that offer support for brain health often contain MCT oil and other ingredients like antioxidants, mitochondrial cofactors, and essential fatty acids that may decrease cognitive dysfunction symptoms or even slow their development.

Good options include Hill's Prescription Diet b/d Brain Aging Care and Purina Pro Plan Veterinary Diets Neurocare.

Activities and life enrichment

But what’s arguably most important for dogs with dementia is keeping them engaged in the world. They still need to interact with their family members and, to the greatest extent possible, keep doing the things they have always loved to do. A familiar routine can help ease anxiety.

So take lead walks and let them sniff everything they want to sniff. Meet new people and pets, as long as you can do so safely. Introduce new toys and food puzzles. Review old tricks and training commands and try to teach some new ones. If you are unsure of ways to help your dog, call your dog's vet clinic for a chat with the team for some suggestions.

All of this should remain enjoyable, however. Don’t push your dog too far, and keep your sessions short but frequent. If your dog starts to look tired, bored, or irritated, it’s time to stop.

With advanced dementia, even the sweetest dog can become aggressive. Ask your veterinarian for advice if you see any signs of aggression, including growling, snarling, snapping, or biting.

There may be hope for the future

Scientists are continuing to study cognitive dysfunction syndrome in dogs, in part because of its similarities to Alzheimer’s disease in people. Not only are we learning more about these related conditions, but treatment advancements appear to be on the horizon.

For example, dogs with cognitive dysfunction syndrome in a small study showed great improvement after researchers injected skin-derived stem cells into a part of their brains called the hippocampus. Two out of five dogs had a complete reversal of their symptoms that lasted up to two years.

While we wait for the results of more studies like this, rest assured that there are things you can do right now to help your dog. Some treatments for dementia, like going outside for a lead walk, are inexpensive, but others are not.

Costs can add up since treatment will likely be necessary for the rest of a dog’s life. Consider a dog insurance policy before a dog develops signs of illness - if you need any help, we're here.

A person high fiving a dog

Get £15,000 lifetime vet fee cover with our Complete policy.

A person high fiving a dog

Jennifer Coates, DVM
Veterinarian, Veterinary Writer, Editor, and Consultant

Dr. Jennifer Coates is a writer, editor, and consultant with experience in veterinary medicine, science, animal welfare, conservation, and communications. She has written for outlets including petMD, Chewy, and ManyPets.