only one mouse has mites

Question
Is it possible for one of my mice to have mites and the others not have them? One of the first mice I bought is constantly scratching and has thin hair in spots, plus the occasionally sore in her ear. The others look very healthy and hardly ever scratch.

Answer
Dear Rebecca,

It is very possible that only one mouse is *affected* by mites.  The fact is, most mice have mites.  However, they are not affected by then until something goes wrong-- they get a little ill, get old, lose the friend who used to groom them, or anything which might slightly lower their ability to protect themselves against the mites.  It's the same way that we are infested with millions of germs all the time but we rarely get sick from most of them. It isn't until one gets too plentiful that we get ill.  

Because the mouse with mites will get more mites from the healthier mice, all the mice in the cage must be treated, and the cage completely cleaned, if possible bleaching or boiling plastic or glass items and throwing away what you can't clean thoroughly.  Also, when the mice are treated, some of the mites are in their eggs and aren't affected by the poison, so the entire treatment and cage cleaning must be repeated 7-10 days later as well. My other piece of advice is to hold the mouse being treated over a bed or couch, because they can panic when wet; and make sure the mice are absolutely warm and dry before returning them to the cage.

I use a flea and tick spray from 8-in-1.  There is a rodent spray and there is a bird spray.  The bird spray is half as potent as the rodent spray.  Some mice are very sensitive to the chemical used, and can experience a painful skin reaction within a few hours, which will cause them to squeak when touched.  Starting with the bird spray can help to avoid this problem.  However, if the mites come back, the more powerful rodent spray would have to be used.  You might want to use the rodent spray on the affected mouse and the bird spray on the others.  

There is also the possibility that it is something else besides mites, though mites are very common.  A vet can do a skin test to find this out.  Ringworm is an occasional culprit.  

Best of luck to your mouse crowd!

squeaks,
Natasha