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How Long Do Pet Mice Live?

how long do mice live

Those who are looking for small pets might be interested in adopting mice.

Mice are not that hard to take care of, and they're rather cute. Still, it's best to learn about their lifespan and what impacts pet mice's life expectancy before adopting one.

Pet mice lifespan

Pet mice live for around two to three years. This means you'll be caring for these pets for quite some time if all goes well.

The life expectancy of pet mice depends on many factors, including diet, stress level, and living conditions.

There are only a few types of mice that are sold as pets. Most people buy fancy mice as pets. They're commonly sold in pet stores and are raised specifically to live with humans.

Find out your mouse's age in human years with our online calculator

As for wild mice, they don't live all that long due to all of the dangers they face, like predators and lack of food. It's common for wild mice to live for less than one year.

What affects pet mice's life expectancy?

As you'd expect, there are many things that can negatively impact the life expectancy of a pet mouse. Below, you'll learn a bit about the factors that you need to look out for.

Stress can affect your pet mouse’s lifespan. Sudden and loud noises, a tiny cage, and loneliness can result in a shorter life for your pet.

Nutrition is also an important factor. Overfeeding or lack of nutrients and vitamins will decrease the mouse’s life expectancy.

Obesity can also cause various health problems.

Genetics and professional care. Mice are prone to some illnesses that can develop regardless of how well you care for your pet.

Common health issues shortening pet mice life expectancy

Various health issues can shorten the lifespans of pet mice. Knowing about these potential health problems can help you to keep a watchful eye.


Sadly, pet mice sometimes develop tumors. These tumors can become malignant within weeks, too.

It's important to monitor your pet mice for tumors. If you notice that a mouse has developed a tumor, you can contact a local veterinarian.

Tumors in young mice can be treated and removed. However, surgery often gives the pet mouse only a few more months of life.


Pests such as fleas, ticks, and mites are known to bother pet mice. You might even notice bald spots on your pet.

This can lead to significant issues with skin irritation and stress.

And as you already know, stress affects a mouse’s life expectancy.

A veterinarian can prescribe a proper treatment. There are also at-home treatment options available to get rid of fleas, ticks, and mites.

Wet Tail

Wet tail is a very serious intestinal problem. This intestinal issue is caused by stress.

Too much bacteria in the gut can cause diarrhea. And the fecal matter will become foul-smelling.

Often, pet owners don't notice this issue until it's too late. Wet tail is something that can kill a mouse within hours.

If you suspect that there is a problem, you need to take the mouse to the veterinarian immediately.

How to extend your pet mouse's life?

Extending your pet mouse's life comes down to caring for it to the best of your ability. There are many things you can do that have a positive impact:

  • Avoid stressing your pet mouse;
  • Do your best to clean the mouse cage regularly and keep it disinfected;
  • Give the pet mice enough room to live;
  • Keeping mice in pairs or small groups is beneficial;
  • At the same time, avoid overcrowding the cage with too many mice;
  • Focus on feeding pet mice a healthy diet;
  • Give the pets recommended foods and portion things out properly;
  • Place toys in the cage so the mice can play and be active.

If you're able to give the mice a good environment to live in, it'll be much easier to keep them alive for as long as possible. In some cases, your pet mice might live for as long as three years.

Or who knows, maybe your mouse will live for over 7 years and 7 months, beating the world record for the oldest pet mouse.