We know that dogs can be at least as important to us as our human family and friends. We know that they can improve our physical wellbeing and mental health. And now, a new study published in Scientific Reports has found that dog (and cat) ownership is associated with slower mental decline as we age.
The study, organized by a psychology research group at the University of Geneva, analyzed the statistics collected from eight “waves” of the Survey of Health and Retirement in Europe (SHARE). Over an 18-year period, the authors measured two buckets of mental health markers in the surveyed Europeans who were 50 years or older. Those were executive functioning (the management of multiple tasks and goal-oriented planning) and episodic memory (the recall of specific events).
The study found that all individuals showed a decline along those two categories as they grew older, but here’s the good news: The mental decline was slower for pet owners than for those with zero pets. And dog ownership was far and away more impactful than fish or bird ownership—which, sadly, didn’t offer much cognitive upside according to the data. This is not to say that birds and fish are not worthy and fun animals to care for, but dogs seem to offer more mental exercise.
The study found that cats can offer benefits too. Dog owners kept a sharper memory for longer—both immediate and delayed recall—while cat owners preserved “verbal fluency” and delayed recall. For those not up on memory science: Delayed recall is the ability to remember information after some time has passed and immediate recall is the ability to remember information that was just presented.

The authors of the study served up several hypotheses as to why dog and cat owners demonstrated better cognitive results as they aged. These were based on their own findings, plus a large swath of previous research on animal-human relationships. One possibility they raised was that when it comes to pet fish, the comparatively shorter lifespans “may potentially limit the level of emotional connection one is able to develop.” Furthermore: “Bird ownership may negatively affect the owner’s sleep quality due to the increased noise levels, which has [sic] been shown to be associated with cognitive decline as well.”
The authors added that it’s possible cats and dogs offer more stimulation than “less demanding pets” (their words, not ours). “While the research is so far relatively scarce, there has been evidence of an increase in prefrontal brain activation and thus stronger attentional processes and emotional arousal caused by interaction with a dog compared to a non-living stimulus,” they wrote. The authors also posited that having a dog or cat helps owners build a strong in-person social network with other people, or shore up a limited social network. Studies conducted during COVID-19 lockdowns support the latter notion.
The study’s authors mention that further research could help support policies that would make pet ownership easier and more accessible for an aging population. This conclusion to the study gets at one difficult aspect of adopting a dog—that it’s a tremendous responsibility, and not feasible for everyone. Still, it’s nice to have the data to support the suspicion that most dog owners already have: as we care for dogs, dogs care for us.