Swaying mouse.

Question
QUESTION: Hi Tamarah.

One of my mice in a group of three is displaying a slightly strange behaviour. She sometimes stops what she is doing and sways slowly from left to right. It seems to only last a few seconds then she continues doing whatever she was doing.
Her eyes are also smaller than the other two mice's eyes. They don't appear to have any discharge, but they do appear a little sunken in. I'm afraid we didn't pay enough attention when choosing them from the pet store and have only had them for a few days. I can't say if this is a development, or whether this was the case in the store too.

I have read about waltzing mice with inner ear infections, but the descriptions I have read don't seem to fit my mouses behaviour. She can walk in a straight line, climb the cages bars, run on the wheel, no problem. She doesn't sway while walking. She just stops everything and sways.

Apart from the swaying and the eyes she seems perfectly healthy. Eats, drinks, plays and is no trouble to handle, although she is still a little more nervous than the other two.

If a vet trip is required I don't know whether to take it myself, or return it to the shop. I think the shop owner is likely just to swap the mouse for a healthy one rather than find the cause of the problem and try and heal the mouse.

ANSWER: Hi Jack,

While I've never seen this behavior in mice, I did happen to have a pet rat with the exact same behavior.  She actually went on to live a totally normal and long, if not wobbly, life.  Obviously rats and mice are not quite the same creatures, but I am wondering if they might share the same problem.

It's definitely not waltzing, like you said, but it could absolutely stem from a neurological problem.  With inner ear infections you usually see the head tilt to the side and balance is affected - this is a 24-7 thing and not just on occasion, so I agree that the problem is in her brain and not her ears.

So now the question is what's causing what kind of problem in her noggin.  Since you mention that her eyes are set differently than her cage mates, I don't think the problem stems from a tumor or anything like that.  What I think is happening is developmental, a result of her breeding, that may not have been noticeable at the shop.  It could be permanent and may or may not even affect her (like I said, my rat paused and wobbled her entire life but was a perfectly friendly, happy little girl), or it could be temporary.  Sometimes when animals do not get enough nutrition growing up or were the runts of their litter they don't grow at the right pace.  If I were you, I'd give her a week or two to see if she grows out of it at all and if the behavior changes - for better or for worse.  Since you've noticed the sunken eyes and the swaying there may be other problems below the surface that haven't manifested yet, but the only way to discover that is with time.

It's a bit of a lottery, but I do not think there is anything a vet or the shop would be able to do to fix the problem.  Of course, it never hurts to ask!

I hope she's okay, but please do let me know if you have any more questions, or if her situation changes and you need advice!
-Tam

---------- FOLLOW-UP ----------

QUESTION: Hello Tamara,

Thank you so much for your reply.
Unfortunately she dies yesterday so whatever the problem was it was too late to do anything about.
I noticed she was being very inactive late the night before last. Unfortunately the only thing I could do was look her over myself, again, once being handled, and after for a while, she seemed quite happy with no noticeable behavioural problems other the the occasional stop and sway.

Her turn for the worse was terrible timing as I had an operation yesterday and had to be at the hospital in the morning and had to stay overnight. At such short notice there was no one I could get to keep an eye on her or take her to the vets for me. Besides, as you said there was probably nothing they could do for her, but it would have been nice to have been sure.

So thank you again for the advice, sorry that in the end I asked too late to help her. I will look over your answers for introducing a new mouse as I think three is better than two.

Jack.

Answer
I'm so sorry for your loss.  With that fast of a decline I really don't think anyone could have helped her, but I'm happy to hear you'll be getting the others a new friend.  Mice deal with loss the same ways we do and they may need a lot of comfort and love from you over the coming days.

Hope you are well,
-Tam