Body size influences cognitive aging in dogs

Does size matter when it comes to aging in dogs? While it is known that smaller breeds tend to live longer than larger ones, researchers at Eötvös Loránd University have investigated how size differences may impact the age of dogs in terms of cognitive abilities.

Variations in life expectancy 

The life expectancy of dogs varies significantly among breeds. Giant breeds generally live up to seven years, while small breeds live up to fourteen years. 

Additionally, mixed breeds typically outlive purebreds, partly because they are less likely to suffer from inherited genetic diseases. 

Aging onset 

Based on data from over 15,000 dogs, the researchers discovered that aging in behavioral and cognitive aspects typically begins at around ten and a half years. However, there is variation in the onset and rate of aging based on the dog’s size. 

Dogs weighing over 30 kilograms (approximately 66 lbs) might start showing signs of aging two to three years earlier than their lighter counterparts. But their decline rate is slower. 

“Larger dogs experience a physical breakdown at an earlier age, and the accumulating illnesses, and degradation in sensory functions leads to ‘old age behaviors’ long before their mental decline would begin,” explained Borbála Turcsán, first author of the study.

Cognitive health

Interestingly, dogs weighing under seven kilograms (14 lbs) showcased a four-fold higher prevalence of cognitive decline in their golden years compared to the bigger breeds. 

This aligns with the concept that while larger breeds might have a shorter overall lifespan, they generally undergo a more restrained cognitive decline.

Breed impact

The researchers also found that long-nosed (dolichocephalic) breeds like greyhounds and purebreds had a higher susceptibility to cognitive decline in their later years compared to meso- and brachycephalic breeds and mixed breeds.

Perception of aging

An intriguing observation was that dog owners start perceiving their pets as “old” from the age of six, regardless of their size or breed. 

“Owners consider their dogs ‘old’ four to five years earlier than would be expected from behavioral data. This may be due to graying and barely noticeable changes,” explained Enikő Kubinyi, head of the Senior Family Dog Project.

Study implications 

The study shows that a dog’s body size not only determines its life expectancy but also its healthspan. Nevertheless, it’s essential to note that these effects are not uniform across all size ranges. 

It is predominantly the extreme size categories – the very small (toy) and the very large (giant) – that exhibit noticeably different aging trajectories. 

Turcsán advises potential dog owners aiming for longevity and health balance to consider breeds in the 10-30 kg weight range, as they tend to have a more extended healthspan in proportion to their predicted lifespan compared to both their smaller and larger counterparts.

—

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

—

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.