What Makes a Dog "Forget"? A Deep Dive into Dementia Risk Factors in Senior Dogs

Key Takeaways in 1 Minute

• Age is the number-one risk factor — each additional year raises the odds of dementia by 52%.
• Dogs that are not very active are up to 6.5 times more likely to have dementia than very active dogs.
• A history of eye, ear, and neurological disorders is linked to higher risk.
• Genetically, no specific gene causing canine dementia has been found yet — unlike the APOE gene in humans.
• These figures are "associations," not proven "causes" — but they help us care proactively.

In an earlier article, we got to know canine cognitive dysfunction (CCD) in senior dogs and how to spot its signs. Today I want to take you one step deeper: "What makes some dogs more prone to dementia than others?" Because knowing the risk factors in advance is the key to planning care and slowing the disease early. Review the basics in our guide to understanding dementia in senior dogs.

The Largest Study Yet: The Dog Aging Project

The most reliable risk-factor data we have today comes from the Dog Aging Project, which analyzed a remarkable 15,019 dogs across the United States — a very large sample in veterinary science (Yarborough et al., Scientific Reports, 2022). This gives us a clearer picture of risk factors than ever before.

Clear Risk Factors the Research Found

1. Age — the Most Important Factor

Controlling for all other characteristics, each additional year of age raised the odds of dementia by 52%, and prevalence rises exponentially with age. Strikingly, an expert from NC State noted that once dogs reach 15, they have yet to see one that is completely normal (National Geographic, 2022).

2. Low Physical Activity

Comparing dogs of the same age, health, breed, and sterilization status, dogs that were not active were up to 6.5 times more likely to have dementia than very active dogs.

A caution on interpretation: researchers stress this is only a "correlation." We can't yet say whether "inactivity leads to dementia" or "dementia makes dogs move less" — more research is needed. Either way, regular exercise only brings benefits.

3. History of Eye, Ear, and Neurological Disorders

Dogs with a history of neurological disorders (1.8× risk), eye disorders (2.2×), and ear disorders (2.0×) had higher odds of dementia. This mirrors humans, where vision and hearing loss are linked to dementia risk, because reduced sensory input means less stimulation for the brain.

What About "Genetics"? Does It Play a Role?

A question many owners ask is, "Is dementia in dogs inherited?" To be candid with the latest review: so far, no specific gene mutation causing canine cognitive dysfunction (CCD) has been found in dogs (Prpar Mihevc & Majdič, Frontiers in Neuroscience, 2019). This differs from humans, where the APOE gene is the major genetic risk factor for Alzheimer's disease (and the APOE4 variant is actually unique to humans).

Interestingly, research finds that CCD prevalence doesn't differ markedly between breeds — smaller breeds are simply "reported" more often because they live longer, giving the disease more time to appear. In short, canine dementia is likely the result of a combination of age, background genetic factors, and environment rather than a single gene — but knowledge about the specific genetics of CCD remains very limited and is an area researchers are still studying.

Important: "Dementia-Like" Signs May Come from Other Diseases

I have to emphasize this especially, because canine dementia is a "diagnosis by exclusion" — meaning other causes must be ruled out first. For example:

• Accidents in the house may come from a bladder infection, not dementia.
• Confusion and pacing may come from a brain tumor or pain from arthritis.
• Research found that a number of senior dogs showing CCD signs actually had underlying physical illness (like kidney disease, liver disease, or cystitis).

So when you see unusual signs, don't just assume it's "old age" — always see a veterinarian to rule out other conditions first.

Good News: We Can Reduce Risk and Slow the Disease

We can't stop age from advancing, but many risk factors are within our own hands:

• Keep your dog active: regular, age-appropriate walks and exercise. In humans there's strong evidence that staying mobile slows dementia and may even reverse it a little in early stages.
• Care for eyes and ears: check and treat vision/hearing problems early to keep the brain stimulated.
• Manage pain: arthritis pain relief (under veterinary guidance) helps dogs move more and stay active.
• Stimulate the brain: puzzle toys, learning new commands, and socializing build neuroplasticity. Read more in mental enrichment for dogs.
• Antioxidant-rich diet: research found that an antioxidant-rich diet combined with brain stimulation helps slow cognitive decline in dogs.
• Annual health checks: especially in senior years, to screen for CCD and comorbidities early.

Read more on extending quality years in Healthspan: 6 ways to extend your dog's life and on exercise in our dog exercise guide.

The Vet's Final Note 

Understanding risk factors isn't meant to worry us, but to help us "care with awareness." Because dementia is a progressive and mostly irreversible disease, starting care in the mild stage gives the best results in slowing it and preserving your dog's quality of life for as long as possible. Most importantly, your own daily observation is the best screening tool of all. 

Medical disclaimer: Most risk-factor data is associational, not a diagnosis or a causal conclusion. If your dog shows unusual signs, see a veterinarian to rule out other conditions and plan care.

Want to care proactively for your senior dog and understand their individual risks? Reach out to me and the Geneus Pet team anytime. 

References

1. Yarborough S, Fitzpatrick A, Schwartz SM, et al. Evaluation of cognitive function in the Dog Aging Project: associations with baseline canine characteristics. Scientific Reports. 2022;12:13316. Nature
2. Bittel J. Dogs' risk of dementia increases by half every year. National Geographic. 2022. nationalgeographic.com
3. Canine Cognitive Dysfunction: risk factors and management. Veterinary Information Network (VIN). vin.com
4. Prpar Mihevc S, Majdič G. Canine Cognitive Dysfunction and Alzheimer's Disease – Two Facets of the Same Disease? Frontiers in Neuroscience. 2019;13:604. NCBI PMC