Guide to Canine Cognitive Dysfunction

Joseph’s husky sits and stares into space a lot. Shameka’s Russell terrier paces for several hours each night. Emilia’s small mixed breed has lost his house training. He comes in the doggie door and eliminates in the house right in front of her. And Teri’s dachshund suddenly gets scared of Teri’s son, even though the doxie has known and loved him all her life.

What all these dogs have in common is that they have been diagnosed by their veterinarians with canine cognitive dysfunction (CCD).

CCD is a term for mental decline that results from physical brain changes in aging dogs. It is a neurological condition with behavioral symptoms. It is different from normal aging. It is also called cognitive dysfunction syndrome, dog dementia, and doggie Alzheimer’s.

How Common Is Canine Cognitive Dysfunction?

Dementia in dogs is not familiar to many dog owners but is fairly common. Many people think their dog’s odd behaviors are from normal aging when the dog is actually developing abnormalities in the brain. Many cases are never diagnosed. The prevalence of CCD has been estimated from studies to be from 14% to over 60% in dogs over eight years old. Several studies have confirmed that the risk increases with age. One study showed that 20% of dogs 11-12 years old had a symptom in at least one category (see below for symptom categories). For dogs 15-16 years old, 68% had symptoms from one category and more than a third of the dogs in this age group had symptoms in two categories (Landsberg et al, 2017).

We need to get the word out about CCD and educate dog owners that it is different from normal aging. In one study, even owners whose dogs were diagnosed with CCD didn’t seek veterinary help about it. But vets can help. It’s a medical condition.

Cats get cognitive dysfunction syndrome, too. It is even less recognized in cats than it is in dogs (Landsberg et al, 2017).

Similarity to Human Alzheimer’s

The similarity of CCD to Alzheimer’s in humans is more than on the surface. The ways that the brain changes in the two conditions are similar. Humans with Alzheimer’s and dogs with CCD both get “beta-amyloid plaques.” These are tissue changes in the brain that block the normal communication between neurons (Cummings, Head, Afagh, et al. 1996). Humans get some other brain changes too, like “neurofibrillary tangles.” These are found in some dogs with CCD but are not as common as in humans with Alzheimer’s (Papaioannou et al. 2001). Some scientists believe this is because dogs have shorter lifespans than humans, so their cognitive dysfunction doesn’t progress as far.

Many medications and methods that are considered as treatments for human Alzheimer’s are first tested on dogs. Lots of the symptoms are similar between the two diseases are similar as well (Cummings, Head, Ruehl, et al. 1996).

Beta-amyloid plaques in brain
Beta-amyloid plaques in brain


The first way symptoms of CCD were classified was under the acronym: DISHA. (Landsberg,  Nichol, and Araujo, 2012). This stands for:


Interactions with people and other pets that have changed

Sleep-wake alterations

House soiling

Activity-level alterations

But DISHA does not cover many other important symptoms.

These others include:

•Memory and learning problems
•Appetite changes
•Anxiety and depression (Landsberg, Nichol, and Araujo 2012, 754).

Here are some specific behavioral symptoms that can be associated with canine cognitive dysfunction.


•Appearing lost or confused
•Pacing back and forth or circling in one direction
•Staring off into space or at walls
•Walking into corners or other tight spaces and staying there
•Getting lost in familiar places
•Getting trapped under or behind furniture
•Waiting at the hinge side of the door to go out
•Failing to get out of the way when you open a door
•Difficulty getting all the way into bed
•Falling off things
•Having trouble with stairs and ramps

Interactions with People and Other Pets that Have Changed

•Seeking attention less, or seeming withdrawn
•Acting frightened, shy, or avoidant of known people
•Losing enthusiasm for play
•Interacting less with other animals in the household or getting aggressive towards them

Sleep-Wake Alterations

•Sleeping more during the day and less at night
•Wandering at night
•Startling easily

House Soiling

•Forgetting how to “ask” to go outside
•Forgetting housetraining entirely

Activity Level Alterations

•Being more sedentary/passive
•Being more agitated or performing repetitive behaviors
•Barking for no clear reason and/or for long periods
•Being quiet when barking would usually occur

Memory and Learning Problems

•Forgetting cues and trained behaviors
•Having difficulties learning anything new
•Failing to remember routines, or starting them and getting only partway through
•Not responding to name

Appetite Changes

•Losing appetite
•Experiencing trouble eating or drinking (finding the bowls, aiming the mouth, keeping food in the mouth)
•Having an increase in appetite

Anxiety and Depression

•Getting generally more fearful or anxious
•Becoming scared of things that used to be fine
•Chronic depression

Physical Signs

There is preliminary research that indicates that there may be some early physical symptoms that correlate with the onset of canine cognitive dysfunction. These are visual impairment (which can happen for several other reasons in aging dogs but did correlate with CCD), swaying, falling, and possibly dropping of the head (Ozawa et al, 2019).

rat terrier with canine cognitive dysfunction stands in a hallway
terrier with dementia facing wall
elderly blind pug

Getting a Diagnosis

The most important thing to know about determining whether your dog has CCD is that you can’t diagnose your dog yourself. Even though there are handy lists of symptoms all over the Internet, including one on this page, every symptom on those lists could also be a symptom of another disease or condition. Brain tumors, certain liver conditions, tickborne diseases, and other conditions can cause similar symptoms. Diagnosing canine cognitive dysfunction means ruling those other things out. It’s called a diagnosis of exclusion, and it takes a vet to do the appropriate tests to do that.

Dementia can also be diagnosed through an MRI, but many vets don’t have the equipment, and it can be an expensive test if they do.

You can fill out this checklist to take to your vet if you think your dog may have cognitive dysfunction.

Regular vet visits are important for older dogs anyway. The American Animal Hospital Association (AAHA) recommends checkups every six months for senior dogs. Older dogs are more likely to be on medications that need monitoring. And they are more vulnerable to illness, disease, and pain (not to mention cognitive dysfunction). The better your vet knows your dog, the better he or she can catch a problem like CCD early.


There is currently no cure for canine cognitive dysfunction. There are prescription drugs and supplements that have been shown to have various beneficial effects for dogs with CCD. Some appear to slow down the progression of the disease. There are some diet and enrichment interventions that appear to help. There is also a surgical procedure currently in clinical trials in Australia that shows promise.

Available Prescription Drugs

Selegiline is prescribed in the U.S. and Canada. It is used in humans for Parkinson’s disease. It is FDA approved for dogs with CCD in the U.S. and marketed under the name Anipryl. It seems to have the best results in studies (Milgram et al. 1993).

Nicergoline is prescribed in the United Kingdom. It enhances blood flow to the brain and is thought to enhance the transmission of neurons (Siwak, Gruet, Woehrlé, Muggenburg, et al. 2000).

Propentofylline is used in some European countries and Australia. It is thought to increase blood flow by making the red blood cells more pliable and preventing them from clumping together (Siwak, Gruet, Woehrlé, Muggenburg, et al. 2000). It is sold as a veterinary medicine in Australia under the name Vivitonin.

Drug Currently Being Tested

Ropesalazine is showing promising results for dogs with CCD in clinical studies in Korea.


Two foods have been clinically tested and shown to have some preventative effects against canine cognitive dysfunction. They are Hill’s Prescription Diet b/d Brain Aging Care and Purina One SmartBlend Vibrant Maturity 7+ Formula. Both of these foods include ingredients that are thought to positively affect the brain. But it is not yet known which ingredients, or which in combination, are responsible for the apparent benefits for some dogs.


Enrichment means anything that makes the dog’s life more interesting and involves his body, senses, and brain. Enrichment has been found in studies to be preventative against CCD and also helpful in slowing the progress for dogs who already have the condition. Interestingly, in the diet studies for the foods above, the best results were found in the dogs who had both the special diet and enrichment. Several blog posts and this page have ideas for enrichment for senior dogs.


S-Adenosyl methionine (SAMe) is an amino acid that appears to have a range of beneficial effects. It has been studied in cats, dogs, and humans. It’s available as a supplement under many brand names. Studies of SAMe on senior dogs in 2007 and 2012 both showed beneficial results. The 2007 study showed a 57 percent increase in activity (versus 9 percent in the placebo group). It also showed a 60 percent increase in “awareness” (versus 20 percent in the placebo group) (Rème et al. 2007).  In the 2012 study, the conclusion was that a brand name supplement of SAMe enhanced some learning capabilities in the dogs. It didn’t appear to help with memory.

Phosphatidylserine is a part of a membrane that is found in a broad range of cell types in plants and animals. It has been used in human patients with Alzheimer’s, and is included in the supplements Senilife and Aktivait for dogs and cats. There were two small studies of these supplements in 2007. In both the studies, the dogs taking the supplement showed improvement in several categories of dementia behaviors.

Apoaequorin is a protein that can help stabilize the concentration of calcium in cells. It is sourced from jellyfish. It’s said to combat a certain neurotoxin that is associated with Parkinson’s disease and dementia in humans. It is a component of the dog supplement Neutricks. Two studies in 2015 indicated that dogs treated with apoaequorin showed improvement in performing learning and attention tasks.

Adrafinil is a drug that promotes wakefulness and has been studied on senior dogs. In one study it improved dogs’ attempts to learn tasks (Milgram et al. 2000), and in another study, it prompted increased locomotion without repetitive, compulsive behavior. However, the dosing may be difficult, and more studies are needed (Siwak, Gruet, Woehrlé, Schneider, et al. 2000).


Research at the University of Sydney has already helped two senior dogs with dementia and may eventually aid humans with Alzheimer’s disease. This novel approach is not based on medication, supplements, or activities. Researchers retrieve skin stem cells from the subject dog and convert them into neural stem cells, then inject them into the dog’s brain.  The procedure is not to be undertaken lightly since it involves anesthetizing the dog twice and brain surgery. But two dogs with dementia have successfully undergone the procedure with promising results, with the apparent reversal of some symptoms of dementia.

Consulting a Specialist

Whether it ‘s when trying to diagnose your dog, or when treatment is indicated, you may want your dog to see a specialist. Just as humans can see psychiatrists or neurologists for cognitive problems, dogs can see veterinary behaviorists.

Board certified veterinary behaviorists are vets who undergo training in animal behavior after veterinary school. They must pass a rigorous examination before being certified. They are trained to treat behavior problems as well as underlying medical problems and often work together with a general vet and a credentialed dog trainer.

This interview with a veterinary behaviorist can show you the kinds of things they can help with and how they approach their work.

You can ask your vet to consult a veterinary behaviorist (many will do vet-to-vet remote consults) or approach one yourself. The American College of Veterinary Behaviorists maintains online listings for these professionals in the United States.

Here is an excellent article on cognitive dysfunction by Board Certified Veterinary Behaviorist Dr. Lore Haug:

Aging and Cognitive Dysfunction in Dogs and Cats

And here is a literature review on cognitive dysfunction in dogs:

Literature Review: Canine Cognitive Dysfunction

beta amyloid plaques in brain

There Is No Cure for Canine Cognitive Dysfunction

This is important. If anyone claims they can cure the effects of canine cognitive dysfunction, they are misguided at best. Keep in mind that in CCD, the actual brain deteriorates. Supplements, diets, and prescription drugs can’t re-grow sections of dogs’ brains. The stem cell research being done in Sydney, Australia, may come close, but will not be widely available even if it passes the clinical trial stage. And not many dogs would be good candidates since it involves two surgeries.

But some medical, supplemental, diet, and lifestyle changes (enrichment) can help you and your dog enjoy the time he’s got. Medications can particularly help with anxiety, one of the common symptoms. Your dog’s life is not over when he starts losing some of his cognitive capabilities. But your life will get more challenging, so be sure and take care of yourself as well.

Coping with Your Dog’s Dementia

Here are some basic tips about coping with a dog with dementia in your home. I have many more such tips in my book: Remember Me? Loving and Caring for a Dog with Canine Cognitive Dysfunction.

House Safety
Just as you puppy-proofed your house when your dog was young, now you need to make your house safe for your old dog. Make sure there are no spaces where your dog might get trapped. Remove things they may stumble over, slots they can’t back out of, and tight places where they might put their head.  Be sure you don’t have tangles of cables they can get trapped in. Your dog may forget how to back up.

If you have hardwood, concrete, or smooth tile floors, you may need to put down something to prevent your dog from slipping. I use a combination of rubber-backed bath mats and yoga mats. As your dog loses mental functioning, be sure there are no steps or ramps in his space. It needs to be all one level. You can use baby gates to separate a safe room or section of the house for him.

Dog with dementia stuck under table

Food and Water
You’ll need to pay attention to your dog’s ability to eat and drink. Make both as easy as possible. You can put his food and water bowls in corners so he doesn’t walk through them and tip them over. Dogs with dementia often end up in corners anyway as they wander. As dementia progresses, your dog may have a hard time telling what the level of the water is. Try to place bowls at the optimal level. Elevate them if that helps. You might want to avoid really shiny drinking bowls if they appear to confuse your dog about the water level.

Observe carefully if your dog loses toileting capability. You still may be able to tell when she needs to go, and work out ways to minimize mess. For instance, Cricket used to sit bolt upright in the middle of the bed in the middle of the night. I knew that meant she needed to go. I would lift her right down to a pee pad that I kept by the bed. Please don’t punish your dog for accidents. Loss of house training is a symptom of a progressive disease and she can’t help it. Punishing her isn’t fair and will only serve to make her scared of you.

two small dogs lounging on a bed
human (Eileen Anderson) holding black and white terrier and giving her a treat

Other Dogs
Be ready to keep your dog separate from other dogs if necessary. As she loses cognitive function and perhaps some vision and hearing, she may not react appropriately in dog social situations. This could put her in danger of being jostled, picked on, or even hurt. I had only one dog who was safe for my dog with dementia to be with. But even then, I separated them when I left the house.

Doors that Open Inward
Be careful about leaving your dog in a space with a door that opens inward. She will often be standing there when you try to go in. You’ll need to learn to open doors slowly,  and lure or gently push your dog out of the way if you have to.

You are likely going to have to handle your dog a lot more as she loses capabilities. If your dog is small, you’ll be picking him up a lot. If he is big, you may be guiding him by the collar or harness. Cricket never liked being picked up, so I started giving her a treat every time I picked her up. The treat helped her accept handling and forget about her discomfort. I am so glad I did that. I probably picked Cricket up 20-30 times a day in her last years. So if your dog isn’t used to being handled, it’s not too late to help her accept it. You can make it a positive experience with treats.

Do whatever you can to keep those problem-solving brain cells going. If your dog knows tricks or other behaviors, try to keep those alive. Set up some simple “find the food” games. You can’t completely stop the progress of dementia, but you may help your dog keep the capabilities she’s got for a bit longer. Food toys are great as long as your dog has a good appetite. But you don’t want to make eating more difficult for a dog who isn’t eating enough.

Take Care of Yourself
Taking care of aging dogs is a lot of work, and it’s doubly hard when they are losing their mental capabilities. Do what you can to take time for yourself.

Euthanizing a Dog with Dementia

Many people who find this site are already struggling with the thought of having to euthanize their dog. No one can make that decision except you, with the advice of your vet. I have some resources on this site about how I made my own decision, and there are many comments from other owners who have had to face this question. You can also check out this Quality of Life scale. It tells you some things to consider when you try to assess how your dear dog is doing.

Please also check out the blog posts here and other resources about enrichment. Enrichment may help your dog keep some capabilities, and it’s a way for you to have fun together as well.

Please pass the word about canine cognitive dysfunction. The earlier it is detected, the better chance there is to slow it down with some of the methods listed above.


Cummings, Brian J., Elizabeth Head, Arman J. Afagh, Norton W. Milgram, and Carl W. Cotman. 1996. “β-Amyloid Accumulation Correlates with Cognitive Dysfunction in the Aged Canine.” Neurobiology of Learning and Memory 66 (1): 11-23.

Cummings, Brian J., Elizabeth Head, William Ruehl, Norton W. Milgram, and Carl W. Cotman. 1996. “The Canine as an Animal Model of Human Aging and Dementia. ” Neurobiology of Aging 17 (2): 259-268.

Landsberg, Gary M., Jeff Nichol, and Joseph A. Araujo. 2012. “Cognitive Dysfunction Syndrome: A Disease of Canine and Feline Brain Aging.” Veterinary Clinics of North America: Small Animal Practice 42 (4): 749-768.

Landsberg, Gary, Aladár Maďari, and Norbert Žilka. Canine and Feline Dementia. Springer International, 2017.

Milgram, N. W., G. O. Ivy, E. Head, M. P. Murphy, P. H. Wu, W. W. Ruehl, P. H. Yu et al. “The effect of L-deprenyl on behavior, cognitive function, and biogenic amines in the dog.” Neurochemical research 18, no. 12 (1993): 1211-1219.

Milgram, Norton W., Christina T. Siwak, Philippe Gruet, Patricia Atkinson, Frédérique Woehrlé, and Heather Callahan. 2000. “Oral Administration of Adrafinil Improves Discrimination Learning in Aged Beagle Dogs.” Pharmacology Biochemistry and Behavior 66 (2): 301-305.

Ozawa, M., Inoue, M., Uchida, K., Chambers, J. K., Takeuch, Y., & Nakayama, H. (2019). Physical signs of canine cognitive dysfunction. Journal of Veterinary Medical Science, 19-0458.

Papaioannou, Nikolaos, Peter CJ Tooten, Anne Marie van Ederen, Jurgen RE Bohl, Jaime Rofina, Thomas Tsangaris, and Erik Gruys. “Immunohistochemical investigation of the brain of aged dogs. I. Detection of neurofibrillary tangles and of 4-hydroxynonenal protein, an oxidative damage product, in senile plaques.” Amyloid 8, no. 1 (2001): 11-21.

Rème, Christophe-Alexandre, Valerie Dramard, Laurent Kern, Joelle Hofmans, Christine Halsberghe, and D. Vida Mombiela. 2007. “Effect of S-Adenosylmethionine Tablets on the Reduction of Age-Related Mental Decline in Dogs: A Double-Blinded, Placebo-Controlled Trial.” Veterinary Therapeutics: Research in Applied Veterinary Medicine 9 (2): 69-82.

Siwak, Christina T., Philippe Gruet, Frédérique Woehrlé, Bruce A. Muggenburg, Heather L. Murphey, and Norton W. Milgram. 2000. “Comparison of the Effects of Adrafinil, Propentofylline, and Nicergoline on Behavior in Aged Dogs.” American Journal of Veterinary Research 61 (11): 1410-1414.

Siwak, Christina T., Philippe Gruet, Frédérique Woehrlé, M. Schneider, Bruce A. Muggenburg, Heather L. Murphey, Heather Callahan, and Norton W. Milgram. 2000. “Behavioral Activating Effects of Adrafinil in Aged Canines.” Pharmacology Biochemistry and Behavior 66 (2): 293-300.

Photo Credits

  • The photo of Frankie, the small black dog facing the wall, graciously provided by Michael Nichols and copyright to him.
  • Oval image of amyloid plaques by Nephron [CC BY-SA 3.0 ( or GFDL (], from Wikimedia Commons.
  • Image comparing a normal brain with a brain with amyloid plaques is a purchased stock photo.
  • Photo of Hazel the pug graciously provided by Blanche Axton and copyright to her.
  • All other photos copyright Eileen Anderson.


  1. Joyce Haggart Gray says:

    Thank you so much for such wonderful
    information. Made me cry for the
    help you have given me. Anything
    I can do and try I will do for my
    Love. If there is any new information
    please let me know. No words
    I can say but you are blessed
    Thank you

    • Eileen Anderson says:

      I’m glad to help, even a little. I will always publish new information here as I learn about it. Take care.


  2. Theo MacKenzie says:

    The link to the Quality of Life Scale is not working, could you please check it?
    This is a wonderful article, much helpful advise but I hope I won’t need it.
    Thank you

  3. Merrill says:

    I don’t know how your website popped up on my phone today but I am in awe of all the information and manner in which you provide it. My dog isjustthe best I’ve ever known. A 16 year old rat terrier mix Roscoe has a couple of signs of dementia, is totally deaf and enjoys his life otherwise. He’s never been ill, has eaten a homemade diet since we rescued each other 10 years ago. His tremors have spread from one hind leg to two and now all four legs but they are not continuous. He had one seizure about 3 years ago. We are completely bonded and together most of the time. He has become more attached and doesn’t leave myside yet still loves to sit on everybody’s lap. It’s me that can’t sleep without him! I postponed my bucket list trip until “after” as I don’t want to leave him in a different environment for a month! I will keep you in mind as he and I progress through this last adventure of his life. thank you for the food enrichment suggestion. Roscoe is very food motivated this will be a good game for him. Again thank you for all of your insight and compassion. it makes me feel better and more confident that I’ll know when our time together must end.

    • Eileen Anderson says:

      Hi Merrill,
      Love me a rat terrier, as you can probably tell! If you are on Facebook, there is a fabulous group called Canine Enrichment. It’s the one that has almost 200,000 members. You can search for things that are appropriate for a senior if you want some more ideas. I hope things go well for you and Roscoe. Keep me posted!

  4. Shelby says:

    Hi there, I wanted to reach out and say hello and thank you. I am currently typing to you at 2am from the floor of my bedroom where I have found my new sleeping area since last night due to my (17yrs Dec. 23) Chihuahua and his antics. I have found Crickets video to be very confirming in what I am experiencing withmy old man, MooMoo. I believe he also has some gastro issues that aren’t helping his confusion and pacing, But that’s not why I wanted to message! I thank you for helping with resources at a time where I feel so helpless and more lost than my old man seems. Thanks to your site I will be bringing the checklist to my vet and taking other opportunities and actions to help Moo adjust. He is my first dog and we have been together more than half the time I’ve been alive. I can’t thank you enough for helping give some insight to what’s going on with my tiny soulmate! 💕🐾

    P. S. I would love to share his photo as well if that’s still available:)

  5. Belinda says:

    Hi Eileen:
    Thank you for the resources and information on this website. I have also read your book. I felt I wasn’t dealing with this all alone. 3 weeks ago I had to put down my 17 1/2 years old Bichon/Maltese cross, Bunny. I can’t remember when she started to show symptoms of CCD but I have to say her changes were subtle and gradual over a period of time. For a long time I wasn’t aware dogs can have dementia. A lot of symptoms she displayed could seemingly be explained away with her getting on age. Gradually I adapted to the changes and then they became new normal. I finally started her on selegeline at the end of last year when her pacing and night time barking was getting out of control. However she had developed GI issues at the same time and her health went downhill rapidly shortly after, so I couldn’t tell if the medication helped. I think she was at a fairly advance stage of the disease at that time. She had always been a healthy, happy and playful dog. Seeing her losing her mental capacity was very heartbreaking. I hope there will be more awareness to this disease and more emphasis being put on the mental health of dogs in veterinary medicine.

    Thank you for the website and thank you everyone for sharing.


    • Eileen Anderson says:

      Dear Belinda,
      I’m sorry for your loss. Also I apologize for my late reply.
      I understand the heartbreak. Thank you for sharing Bunny’s story, and for your kind words..


  6. Marta says:

    Hi Eileen,
    thank you very much for all this.

    I’m reading you from Italy and I’m so glad that I found you.
    Getting information about dog’s CCD is extremely hard in my country and vets seem to consider them already gone when they are finally diagnosed.
    The easy “there’s nothing to do”, but nobody tells you how to cope with you dog gradually losing his functionalities.
    My dog was diagnosed last year at the age of 13 after undergoing an MRI (the vet thought about a brain cancer since he was starting at corners).
    We had to learn how to help him by ourselves. He is still with us but this insidious illness is progressing so fast.
    Every day I have this painful thoughts about eventually having to decide to put him down and I’m experiencing an extremely heartbreaking time.

    Thank you very much for the detailed guide and for sharing you experience. I felt you so much and I also felt for a moment that I was not alone. <3 Hugs.

    • Eileen Anderson says:

      I’m sorry to reply so late but thank you so much for writing. I hope your dog is comfortable, whether still with you or in the next place. I know how lonely it can be, which is why I created this site. Best wishes to you.

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