How Long Do Pet Mice Live?

Finding the right pet for a family involves time, energy, and research. All animals have specific requirements for food, habitat, and living conditions based on the pet. By providing these requirements, pet parents can extend the quantity and quality of their pet’s life.

When researching a new addition to the family, pet parents should also consider their expected lifespan. This lifespan should coincide with the family’s plans and expectations. Small pets, like rats and mice, are intelligent, fun family members but, unfortunately, only live a few years—even with the best husbandry. This shortened lifespan shouldn’t deter potential pet parents; while they don’t live long, mice are typically docile, easy keepers who bond with and enrich their family's lives.

Average Mouse Lifespan

In general, smaller mammal body size equates to shorter life spans. Increased metabolism and rapid heartbeats, as seen in mice, are both factors that cause the body to age quicker, resulting in shorter lives.

A mouse’s heart that beats 250–350 times a minute will generally not live as long as a heart that beats only 30 times a minute (as seen in elephants). Domestic mice typically only live for 1–3 years. Their wild counterparts have an even shorter lifespan; some estimates are 3–6 months and only rarely up to 18 months. This extremely brief life is due to predation, extreme environmental conditions, lack of veterinary care, and inconsistent food sources.

What mice lack in longevity, they make up for in numbers. Mice are sexually mature by two months old. Female mice can have a litter of 10–12 pups. These pups wean from their mother at three weeks old to start the cycle again.

Mouse Genetics

Genetics also play a role in a mouse’s lifespans. Breeders of pet mice often have lines or individuals who live much longer than the average mouse. The San Diego Zoo Park houses the oldest verified mouse, Pat, who is over nine years old. However, this long lifespan is extremely rare, and pet parents should not expect their pet mouse to live this long. Some types of mice are prone to medical conditions. For example, hairless varieties are more susceptible to skin diseases and blue varieties often have hemophilia, which can cause bleeding tendencies and death. White laboratory mice can live over 2.5 years, however. This longevity makes white laboratory mice a common subject of aging studies.

What Makes Some Mice Live Longer Than Others?

While genes play a role in the longevity of mice, the single most significant factor to their long-term survival is diet, environment, and health conditions. Luckily, mice are relatively easy to keep healthy once set up with proper husbandry.

Pet mice do best with large, spacious cages that are well-ventilated and cleaned frequently. Small pets have sensitive respiratory tracts, so the accumulation of waste odors can cause significant disease. Mice are naturally nocturnal but can adapt to their pet parent’s schedule. They easily bond with their family when provided exercise, mental stimulation, and routine handling outside their cage. Their diet should consist of high-quality pellet food produced for mice and rats and fresh water changed daily. Females can live together peacefully but should never be overcrowded. Male mice may fight if kept together.

A healthy mouse is inquisitive, often sniffing their environment and any new items introduced. Their eyes should be clear, their coat smooth and shiny. There shouldn’t be any discharge from their eyes, nose, or mouth. Healthy mice are active, with good appetites and energy levels. It is always a good idea to consult with a veterinarian with any questions pertaining to a mouse’s health.

How to Improve Your Mouse's Lifespan

Work with your veterinarian and family members to help extend your mouse’s life. With proper research and effort, mice are terrific and invaluable pets for many families. Common recommendations to increase their lifespan include:

• Have a veterinarian examine a pet mouse at least every year.

• Feed high-quality rodent pellets, like Oxbow Mouse & Young Rat Food.

• Don’t feed a seed-based diet, which can promote obesity.

• To prevent injury, don’t house males together.

• Avoid cedar chip bedding, which can be toxic.

• Clean the cage often and keep it well-ventilated to prevent disease.

• Provide toys for mental stimulation.

• Provide chew toys to keep teeth healthy.

• Mice are susceptible to extreme temperatures and do best when kept between 65 and 80 degrees.

• Gently handle mice daily for proper bonding and enrichment.

• Provide plenty of safe substrates to encourage natural sleeping and nesting behaviors, such as Carefresh Small Pet Bedding.

Featured Image: iStock.com/Plougmann