Cats may live longer than dogs because of differences in brain size and immune system function, according to new research led by the University of Bath.
Scientists analyzed the maximum lifespan potential of 46 mammal species, a measure reflecting the longest recorded age for members of a given species rather than average life expectancy. Their findings, published in the journal Scientific Reports, showed that longer-lived species tend to carry more genes linked to immune function.
The researchers suggested that an organism’s ability to fight infection, manage cell damage, and keep organs functioning normally may be one of the key drivers of longevity.
Brain size plays a role too
The study also identified a link between brain size and lifespan. Animals with larger brains often have an advantage in adapting to change and avoiding danger. Dolphins can live around 39 years, while whales can live up to 100. Mice, with small brains, live only one to two years.
However, the researchers noted that brain size alone does not explain everything. Naked mole rats can live up to 20 years despite small brains, and bats live longer than their size would suggest. Scientists concluded that longevity likely reflects a combination of factors.
What this means for cats and dogs
Although the study did not directly compare cats and dogs, its findings may help explain the difference. Domestic cats typically live 12 to 18 years, while dogs average 10 to 13 years. Cats have a higher brain-to-body-mass ratio than most dog breeds, a trait the study associates with longer life. Cats also show stronger immune resilience, with some age-related diseases appearing less frequently and inflammatory processes developing more slowly.
