Letting pet dogs 'run with the pack' could be key to maintaining good health across their lifespan – a huge new study reveals – with benefits five times as noticeable as those from other examined aspects of canine life.

The study is the largest of its kind to date; a team from multiple US institutions used data on 21,410 canines across different breeds and mixes to build up a picture of what's good and what isn't for these pooches.

After controlling for factors such as age and weight, the researchers found social companionship with fellow dogs as well as humans was associated with the biggest boost in the animals' health.

"This does show that, like many social animals – including humans – having more social companions can be really important for the dog's health," says biologist Bri McCoy from Arizona State University.

In comparison, what the researchers describe as "financial and household adversity" (including income levels) was linked to poorer health and poorer mobility in the dogs, though the significance was nowhere near as great as it was with socializing.

The team also found that more children in a home was associated with a negative health impact on pet dogs, perhaps because more time spent looking after kids means less time with animal companions.

In addition, dogs in households with higher incomes were more likely to be diagnosed with more diseases. This might seem surprising, but the researchers say that's probably because the more money that's around, the better the access to medical care, allowing conditions to be diagnosed.

A collage of fifteen different dogs
(Dog Aging Project/University of Washington)

It's worth bearing in mind that this analysis relied on reports from dog owners, so some inaccuracies and biases are to be expected. The data is only rigorous enough to show a relationship between two factors – not that one factor (like social companionship) is directly influencing another (like health).

However, there is enough here to indicate the importance of a stable home and a social lifestyle for the well-being of pet dogs.

The amount of care and attention we give our pet dogs, plus their relatively short lifespan, makes them particularly interesting for researchers looking at how society and environment affect health and survival as animals get older.

The survey the research was based on covered all kinds of factors, including diet and activity, but socializing was the clear winner for boosting health. Next, the team wants to find out what kind of mechanisms might be underpinning that link at the biological level.

"In future research, we will look at electronic veterinary medical records, molecular and immunological measures, and at-home physical tests to generate more accurate measures of health and frailty in the companion dog," says psychologist Noah Snyder-Mackler from Arizona State University.

The research has been published in Evolution, Medicine & Public Health.