By Jon Zeller | November 22, 2023

Key points:

  • Dementia in dogs—known as cognitive dysfunction syndrome (CDS) or canine cognitive dysfunction (CCD) —is most common in older dogs.
  • If you notice any signs of dementia in your dog, bring them to the veterinarian as soon as you can.
  • Sometimes dogs who show signs of dementia are suffering from other ailments that are very treatable.
  • Dogs who receive earlier diagnosis and treatment for cognitive dysfunction tend to have better outcomes
  • There’s no cure for dementia—but enrichment, nutritional supplements, and medication can slow its progression or even lead to improvements in a dog’s condition.

Like humans, some dogs suffer cognitive decline as they age. In dogs, dementia is called cognitive dysfunction syndrome (CDS) or canine cognitive dysfunction (CCD). 

This condition can be hard on dogs and their loved ones. But if you are noticing changes in your senior dog’s behavior, don’t ignore them—though it can be difficult to face that a beloved dog is facing a serious challenge, bringing them to your veterinarian can lead to a diagnosis and help them live a happier, more comfortable life.

Which dogs are at risk of cognitive dysfunction syndrome?

Cognitive decline in dogs is strongly linked to age; research has found that it becomes much more likely as dogs get older. Some studies have suggested other risk factors—but age seems to be the most important.

What are the signs of dementia in dogs?

The following is a non-exhaustive list of signs that a dog may be suffering from dementia. Some of these signs may come on gradually. One way to remember them is the commonly used acronym “DISHAA.”

  • Disorientation. Getting lost in familiar places or not seeming to recognize humans and animals that they know
  • Interaction changes. Acting aggressively toward people or animals with whom they’ve previously been friendly, or becoming shy when they used to be more social
  • Sleep-cycle changes. Staying up at night pacing, barking, or whining when they used to sleep through the night
  • House soiling. Seeming to forget potty training, and having accidents at home
  • Activity-level changes. Not wanting to play or exercise when they used to be active
  • Anxiety. Showing fear of new places and situations, showing stress in social situations when they didn’t do so before, or engaging in repetitive behaviors like licking

Many of these signs can arise due to conditions other than dementia, including issues that are common in old-age. Arthritis, for example, can make a dog less willing to exercise, and if they’re in pain they might seem to act aggressively. If you notice changes in your dog, the most important thing you can do is bring them to the vet.

Dr. Katherine Houpt, a veterinary behaviorist at the Cornell University College of Veterinary Medicine, says: “Many people will say, ‘Well, my dog is just getting old,’ which is true—but the dog could have some underlying, curable problem. So it behooves them if they think the dog is acting differently to see their veterinarian.”

How do veterinarians diagnose dementia?

If you bring your dog to the vet because you’re concerned that they may have dementia, the vet will likely start by asking you some questions and performing a physical exam. They may also take blood and urine samples. 

This is because cognitive dysfunction syndrome in dogs is usually a diagnosis of exclusion—if a dog is showing signs of dementia, and a vet’s examination and tests don’t turn up any other reason for the dog’s changed behavior, they’ll infer that the reason may be cognitive decline. 

“In that case,” says Dr. Houpt, “it will be that there’s nothing physically wrong with the dog but he still has these signs, so then you’re going to say ‘perhaps this is what’s wrong.’”

If the vet finds other problems that may be causing signs similar to cognitive dysfunction, they’ll work with you on a treatment plan for those issues. If your dog is suffering from cognitive dysfunction, they’ll talk to you about what you can do to help your dog through it.

How can you help a dog with cognitive dysfunction syndrome?

Unfortunately, there is no known cure for cognitive dysfunction syndrome. However, in many cases, treatment can slow its progression and help dogs enjoy a higher quality of life.


One thing you can do to help a dog with cognitive dysfunction is provide them with enrichment. “It’s up to the owner to help their dog by taking him for nice sniff walks, maybe teaching him new tricks or [doing] nosework,” says Dr. Houpt.

Dr. Houpt says that, while she’s not aware of research showing that enrichment can also prevent the onset of dementia, “it stands to reason that it should help.” She cites agility as one of the activities that can give a dog mental and physical exercise that might extend the time they live before experiencing cognitive dysfunction. Such measures are thought to help people, too. “That’s why I do the New York Times crossword puzzle every night,” she says.

If your dog has undergone changes that make it harder for them to get the physical and mental exercise they used to, don’t give up on them. If a dog can’t jump for a frisbee, they may be able to retrieve a ball you’ve rolled gently. If they’ve lost their hearing, they can train with hand signals. If they’re gone blind, they can use their hearing and touch. Find stimulating activities that they still enjoy.

On the other hand, don’t try to force your dog to act the way that they used to. If they’ve become less social, and don’t want to play with other dogs, let them choose to walk away. Play and socialization are good for dogs, but stress is not—only encourage them to play if they’re having a good time.


According to a 2019 article published in Veterinary Clinics of North America: Small Animal Practice, “diet and dietary supplements have a substantial impact on both the development and progression of cognitive decline” in humans and dogs. Consult with your veterinarian about food or supplements that may improve your dog’s quality of life. Dietary changes recommended by a vet may emphasize antioxidants, medium-chain triglycerides, and omega-3 polyunsaturated fatty acids. Dietary changes work best in combination with other treatments and lifestyle adjustments recommended by a veterinarian.


A veterinarian may recommend medication for a dog with cognitive dysfunction—either to treat the condition itself, or for related problems like anxiety or depression.

Changes to the dog’s environment

Make sure that your dog is safe. If they’re starting to wander, for example, protect them by making sure that they can’t escape the house or the yard to places where they might get lost or encounter physical danger.

There is a lot you can do to help a senior dog with cognitive dysfunction

It is upsetting to see a beloved dog experiencing cognitive decline—but Dr. Houpt thinks that, as long as the dog is safe and comfortable, the condition can be more stressful for humans who are losing sleep or dealing with accidents in the house than it is for the dog.

And Dr. Houpt, who has been seeing dogs in cognitive decline since the 1980s, believes there is some good news in increased awareness and better treatments. 

“People now come to their veterinarian for these problems,” she says, whereas years ago “they might ask a neighbor or a dog trainer—but now both the public and veterinarians are knowledgeable enough to know, ‘Oh, we can do something about this.’”