Ultimate Dog

By Luna Lupus - Reading Time: 12 minutes
dog dementia

Dog Dementia: Cognitive Dysfunction Syndrome (CDS) In Aging Dogs

The canine brain experiences changes as it ages. Research estimates that 28% of dogs aged 11-12 experience cognitive decline, the percentage rising to an unsettling 68% for dogs aged 15-16 years. Despite the high prevalence, cognitive dysfunction syndrome (CDS) is severely underdiagnosed in senior dogs. One study found that out of 14% of recorded cases, only about 2% received a proper veterinary diagnosis.

The reason for this is the long diagnostic process and the lack of education dog owners have about the early onset symptoms of dog dementia. Even when the symptoms become obvious, they are too often dismissed as “normal aging” and left completely unaddressed.

This article will help you recognize the early symptoms, explain the diagnostic process, and share the science-backed natural treatment (and prevention) options you can reach for to support your dog's cognitive health and aging brain. 

Canine Cognitive Dysfunction — Why It Happens & How It’s Diagnosed

Aging affects all organs in the body, including the brain. It physiologically changes as our pet ages — it becomes smaller and lighter, often with a slightly reduced blood flow. Not every dog's brain ages in the same way, though. There are significant changes in a senior dog's brain that are developing cognitive dysfunction.

They have a beta-amyloid plaque buildup, reduction in neurons, depleted neurotransmitters, and a significantly reduced blood flow, impacting oxygen supply to the brain. Many of these changes are observed in humans with Alzheimer's disease, which is why canine cognitive dysfunction syndrome is often referred to as dog dementia or canine Alzheimer’s.

Diagnosing CDS is a long process. It’s based on a structured questionnaire that records the frequency of the dog’s potential dementia symptoms based on the owner’s observations. The vet also needs to eliminate other possible conditions, as CDS can only be diagnosed when all alternative conditions are ruled out.

That can make the process of obtaining a diagnosis an expensive pursuit, especially when we're expecting the other medical tests to come back negative. At a minimum, your vet will want to check the dog's blood and urine, as well as conduct a full bone & joint examination. Additional tests might be suggested, depending on the range of your dog's symptoms. 

Cognitive Dysfunction Assessment in Dogs

One of the best assessment tools is CADES (canine dementia scale). It sorts the symptoms into four groups: spatial orientation, social interaction, sleep–wake cycles, and house soiling. Each item on the scale is given a score from 0-5 (excluding 1) based on the frequency of observation. 

  • 0 points → symptom was never observed
  • 2 points → observed at least once within the last six months 
  • 3 points → observed at least once in a month 
  • 4 points → observed multiple times in a month 
  • 5 points → observed multiple times per week 

The scores for the four symptom groups are added together. Based on the total score, the severity of cognitive decline is determined. A total score between 0-7 indicates normal aging. A score of 8-23 indicates mild cognitive impairment. Moderate cognitive impairment is scored at 24-44, and severe cognitive impairment is scored at 45-95. Here is the full assessment scale: 

Disorientation in a familiar environment (inside/outside)Changes in interaction with man/dog, dog/other dog (playing, petting, welcoming)Abnormally responds at night (wandering, vocalization, motorically restless)Eliminates at home at random locations
Difficulty recognizing familiar people and animals inside or outside the house/apartmentChanges in individual behavior of dog (exploration behavior, play, performance)Switching over from insomnia to hypersomniaEliminates in its kennel or sleeping area
Abnormally responding to familiar objects (a chair, a wastebasket)Weak response to commands and ability to learn new tasks Changes in signalization for elimination activity
Aimlessly wandering (motorically restless during day)Irritability Eliminates indoors after a recent walk outside
Reduced ability to do previously learned tasksExpression of aggression Eliminates at uncommon locations (grass, concrete)

Symptoms of Dog Dementia — The Full Range 

It’s important to know that aging itself is not an illness. When we ascribe symptoms simply to aging, we don’t investigate their causes and solutions as we would for younger dogs. Truth be told, we don’t have a good understanding of the complete range of CDS symptoms. Different dog owners will define irritability or abnormal behavior differently. Certain symptoms of cognitive decline can also be very confusing for the owners, especially aggression and memory loss. One study reported that among 75% of dogs who had at least one behavioral symptom linked to CDS, only 12% of dog owners mentioned it to the vet. 

Cognitive dysfunction syndrome is a neurobehavioral condition, meaning its symptoms are predominantly behavioral, even though they’re caused by neurological changes. DISHA is an acronym that can help dog owners notice early behavioral signs of CDS. It's an expanded version of CADES and stands for Disorientation, Interactions with people and animals, Sleep-wake cycle, House-soiling, and Activity level.

The symptoms falling under this acronym make following a senior dog’s behavioral changes a lot easier as it covers them in more detail than CADES and highlights some behaviors to look out for that dog owners might miss on their own. See the full chart below: 

Senior pet checklist

(Source: Today’s Veterinary Practice, Dr. Lynne Seibert, DVM, MS, PhD, DACVB)

Cognitive Dysfunction Treatment for Dogs

There are three ways to approach the management of canine cognitive dysfunction: dietary, environmental, and medical. Research shows that dietary and environmental treatments work best in combination! The medical approach is solely offered as a treatment option and cannot be given to dogs who aren’t officially diagnosed with CDS. Dietary and environmental approaches are appropriate for dogs in all stages of cognitive decline and can be safely used as prevention, too. There is no official “cure” for this condition, but it can absolutely be slowed down, managed long-term, and even prevented. 

Dietary Strategies for Managing & Preventing CDS 

The canine gut (and therefore their nutrition) has an immediate link with the brain. Because the mental decline of senior dogs is so prevalent, it's important to get ahead of the curve as soon as possible. Start naturally fortifying your aging dog's brain sooner rather than later — prevention is easier than treatment. Once your dog’s brain is affected by a significant reduction in blood flow, all dietary supplements will be less effective.

Dogs with active canine Alzheimer's still benefit from nutritional support, though, especially if you're feeding them fresh, real food. Research leans in favor of feeding a combination of essential nutrients rather than only picking one or two. Certain nutraceuticals (like Aktivait® and Senilife®) have shown promising results in studies, but keep in mind that some of them contain artificial coloring and possibly other synthetic ingredientsThese are the five nutritional essentials for your dog’s aging brain and the real, dog-safe foods you can source them from:

1 — Omega-3

Omega-3 fatty acids are vital for optimum brain health at all ages, but even more so in senior dogs experiencing cognitive decline. The best source of omega-3 is whole fish (raw or cooked). Many kibble products on the market claim high fish content, but it’s crucial to know that nothing can substitute fresh fish! It’s superior in health benefits even when compared to fish oils! Omega-3 deficiencies have been linked to dog aggression, which is a common behavioral sign of CDS. Ensuring a consistent and quality omega-3 source in your aging pet’s diet can help lower their chances (or occurrences) of CDS-related aggressive behavior. 

2 — Antioxidants

Antioxidants slow down the aging process of the canine brain. The most crucial antioxidants for cognitive health are vitamins E and C, alpha-lipoic acid, and beta-carotene. Vitamin E is found in spinach, fish, eggs, and pumpkin. Blueberries, broccoli, and strawberries are great sources of vitamin C. Carrots and spinach both contain alpha-lipoic acid and beta-carotene! These foods are fantastic choices for your dog’s daily diet

3 — Vitamin B12 

Vitamin B12 is important for retaining neurological health and delaying the onset of dog dementia. Deficiencies of B12 are linked to neurocognitive conditions and improper functioning of the nervous system. It should be the core supplement in treating dogs with memory loss and disorientation! The best natural sources of B12 are eggs, organ meats, and quality protein from real meat. 

4 — MCTs (medium chain triglycerides) 

MCTs supply the brain with energy, improving the cognitive performance of aging dogs. MCTs are fatty acids, so they're sourced from certain types of oil. The richest sources are coconut oil and a special MCT oil with an enhanced concentration of MCTs. Research shows that long-term supplementation with MCTs has a positive impact on canine cognitive function, making consistency a key element of treatment and prevention. 

5 — Tryptophan

Tryptophan is an essential amino acid that can only be obtained through diet, meaning dogs can't make it on their own. Tryptophan is a big part of canine mood regulation because the canine brain converts it to serotonin. Serotonin is a neurotransmitter regulating mood, sleep, appetite, pain, digestion, and more. Many troubling behavioral symptoms of cognitive dysfunction syndrome (aggression, sleep disturbances, appetite changes, irritability, high levels of anxiety, etc.) are directly linked to serotonin deficiency. The best source of tryptophan is a quality animal protein in daily diet! It's not enough to only supplement it occasionally — it needs to be a constant part of the canine diet.

Environmental Support for Aging Dogs 

Environmental changes alone can't reverse or slow down the aging of the brain, so they should always be paired with nutritional support. That said, the environment plays an important role in the treatment and prevention of dog dementia. Environmental changes help stimulate important brain functions and address behavioral issues that senior dogs can experience in their late years. 

The foundation of your aging dog’s environment needs to be mental enrichment. The more they use their brain, the sharper it will stay. Engage their brain every day by allowing them to use their nose (sniffing on walks, searching for treats, exposing them to different scents) and to play with puzzle toys that keep them interested enough to train their focus and concentration. Another great enrichment activity is taking your senior dog to new environments! We do this all the time when our dogs are puppies but forget about it when they're older. Exploratory experiences are beneficial for all dogs!

Social connections are a very important and often overlooked aspect of healthy canine aging. Senior dogs need positive experiences with their own species, but the type of doggy friends they have might need to change. Some dogs show lower tolerance for puppies in their senior years or lower tolerance for familiar dogs they previously got along with. They need calm interactions — sometimes, simply being in the presence of another calm dog is enough.

There are other senior dogs, though, who still love to play and engage with younger dogs! They should have that option, as long as it's safe for them physically. If your senior isn’t keen on other dogs at all, social connections are still possible and can involve other pets or humans.

Another overlooked environmental factor is the role of choices. When we give dogs a chance to make independent choices, we’re also giving them a chance to actively use their brain! Dogs with choices are generally more confident with lower anxiety levels. Let your senior dog choose the toys they want to play with, the snack they want to eat, which way to go on your daily walk, where to sleep, and more. 

Aging dogs might be slower in their movements, but they still need exercise. It’s a good idea to let your dog control the pace & duration of their movement and for the owner to adjust the frequency & intensity as needed. The effect exercise has on the canine brain is well-documented, especially when it’s done outside in the fresh air. It improves the oxidation of the brain, ensuring proper cognitive functioning and better effectiveness of nutritional supplements! 

A quiet personal space becomes more of a necessity with each passing year of your dog's life. They need a quiet place to retreat to, a place where they won't be bothered by other pets or kids in the household. Older dogs need more rest! Peaceful rest will significantly lower their anxiety levels, instantly lowering the chances of anxiety-related aggression. Behavioral changes in older dogs pose a big challenge for the owners — ensuring that your dog can retreat away from the daily hustle and bustle can solve many of those issues. 

CDS Medication for Dogs

Selegiline (mainly sold under the brand name Anipryl) is the only approved medication for treating dogs with diagnosed cognitive dysfunction syndrome. In two months, 80% of dogs included in the clinical trial were considered by veterinarians as “slightly improved” or “improved.” Dog owners mainly reported increased activity levels. 20% of dogs didn't respond to the treatment. The package insert includes a warning that Anipryl is not recommended for dogs with aggression because the clinical trial showed increased aggression levels in some dogs. 

Other side effects include vomiting, diarrhea, restlessness, irritability, increased anxiety, neurological issues (including disorientation and incoordination), lethargy, weakness, significant weight loss, panting, UTIs, and respiratory & cardiovascular adverse effects (both appearing in 2% of studied dogs, compared to 0% in the placebo group). These side effects are eerily similar to pre-existing CDS symptoms, so approach this medicine with some caution. We recommend exhausting all dietary & environmental options first. They come without the fear of adverse effects and could show results sooner than in two months. 


Salvin, E. Hannah. McGreevy, D. Paul. Sachdev S. Perminder. Valenzuela J. Michael. “Under diagnosis of canine cognitive dysfunction: A cross-sectional survey of older companion dogs.” Science Direct, 06/2010.

Manteca, Xavier. “Nutrition and Behavior in Senior Dogs.” Science Direct, 02/2011. 

Health Quality Ontario. “Vitamin B12 and Cognitive Function.” PubMed, 01/11/2013. 

Seibert, Lynne. “Management of Dogs and Cats With Cognitive Dysfunction.” TVP, 04/08/2017. 

Anipryl. Zoetis, 07/2019. 

Madari, Aladar. Farbakova, Jana. Katina, Stanislav. Et al. “Assessment of severity and progression of canine cognitive dysfunction syndrome using the Canine Dementia Scale (CADES).” Science Direct, 10/2015. 

Heath, Elizabeth Sarah. Barabas, Stephen. Craze, Graham Paul. “Nutritional supplementation in cases of canine cognitive dysfunction—A clinical trial.” Science Direct, 07/2007. 

Luna Lupus

Luna’s passion for learning about canine psychology and behavior began when she adopted a severely reactive puppy from a local shelter. She is now a big advocate for positive reinforcement and compassionate training. As a writer, she strives to spotlight the topics that fly under the radar and be the voice for all who cannot speak for themselves.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top