Pet mouse think it has a parasite scratching hair off neck

Question
Hi I recently took in a pet mouse of my friends from Petco. When I got her she had paper pellet bedding and a bag of food she had been eating for awhile. My other mouse in a separate cage had shredded wood bedding that I got from Petco. Both girls. I never changed anything except the bedding of the new mouse. Plus I moved. The new bedding was the wood chip bedding I think that's what it's called. I put that in the new Mouse cage after pellets needed to b changed. I only did that cause I thought it would be more fun then paper pellets. So after that they both had wood chips. Fed them the same food and that's it. When I moved I gave them new water once from tap but after that only filtered water. I noticed after living here for a week my mouse had been scratching off it's fur on back of it's neck. I'm not sure if it's mites or stress or an allergy. I do not see any bugs On it's fur just looks like either the bedding on it's fur or dry skin. But it's not very noticeable. Immediately I started trying to figure out what could be causing this scratching. I first started to eliminate things that could be causing it. I removed bedding and replaced it with pellets again. However the other mouse had wood chips too and no scratching. Second I removed all bedding cleaned cage inside out with hot steaming water and the plastic stuff and only put paper back in cage with plastic wheel and house and mouse with olive oil on back. Still scratching. I then removed and sanitized all cage stuff and gave mouse a bath in Luke wa
Water for 20 minutes. She is now scratching less but still biting the bats. I think
She is stressed. I don't see mites at all they must be microscopic if so. The other mouse never scratched still not scratching and I took all the sane precautions. I have cats. I noticed lately that they are kinda shaking their heads and scratching a little here n there. Not sure if it's species specific if the mouse has mites or not. If you have any advice please help!

Answer
Dear Nicole,

One mouse can show problems with mites with a symptom free cage mate. Both should be treated.

The best thing you can do - especially since you might have problems with your cats- is to give each animal a dose of Revolution. You can only get that from a vet. It is super, super easy. A vet can try to diagnose the mouse and they may disagree with me, which is also a good reason to go to the vet. So my suggestion is to bring the mouse to the vet, and while you are there, ask for Revolution. Even if the mouse doesn't have mites, the cats may need it; it isn't dangerous to apply it at all, so you might as well; and it is also very good to have it at home for the future. Ask your vet for the largest cat box they will give, so you can do it again in a month if you need to. A mouse gets a drop on the back of the neck, on the skin and not on the fur. Make sure she doesn't wash herself for ten minutes. The cats too. Of course you follow the instructions on the box or from the vet for the cats.

If this does not help, or the vet doesn't give you Revolution and doesn't solve your problem, I can walk you through other steps including testing for allergies. Feel free to write back.

Best of luck,

Squeaks n giggles,

Natasha