Mouse had bumps on tail and died

Question
Me and my friend both have mice. I am not sure what type. They are both brothers, but are different ages. About two months before her mouse died, it got lumps/bends in its tail. My friend thinks maybe that happens before it dies, i was just wondering if she is right because my mouse is nearly a year old, and i would like to know when hes nearing the end of his life.

Answer
Dear Hannah,

Tail changes are not a normal sign of old age. Typical signs of old age are a hunched-over posture, weight loss, boniness, unclean or messy fur, slowness, and less activity, such as no longer running in the wheel. These changes often happen quite quickly-- the mouse begins to look aged almost overnight. They can live like this for anywhere from a week to over a month. The average lifespan for a mouse is about 21 months; it's most usual for them to live 18-24 months but 15 months is not so unusual, or even over two years in some lucky cases.

I can only think of two reasons for tail deformity: Getting caught in the wheel (it will look bent); or what is called "ring-tail" where the tail develops lumps and constrictions on it, a little like beads on a string. Ring-tail is due to low humidity (dry air). In the wintertime, the air can get very dry because cold air doesn't hold much water, and indoor heat makes it worse. Sometimes you need a humidifier to get some moisture into the air.  Make sure the water bottle is always working by checking it with your fingertip once or more a day.

It is unlikely that your mouse will develop any problem with his tail at any point. I wish him a long and healthy life ahead.

squeaks,

Natasha