Dumbo rats are a breed of domesticated Norwegian rat that, like other rats, have an average lifespan of two years and a maximum life expectancy of seven years with excellent care. The Dumbo gene, responsible for the breed's distinctive large ears, has no effect on lifespan or general health.
Several factors affect whether a rat will live out its expected lifespan. Rats are curious and sociable creatures, and denying them a stimulating cage environment or the company of other rats can worsen their health. Rats, like people, also need exercise and good-quality food. Purebred rats have longer lives on average than rats from feeder lineages.