Hair Loss - No wounds

Question
QUESTION: Hi there!

I just got bought 3 mice about 2 months ago and I noticed the fur on one of them is starting to thin behind the ears and particularly on her left side of her face. Apart from that, her left ear is also prone to turn red occasionally. She has no wounds or scabs or anything to suggest bleeding. I am not too sure why.

At first I thought that she might be allergic to the food - so I eliminated corn kernels and sunflower seeds. That improved the redness of the ear, however I still notice that her fur is still thinning.

My next guess is mites - but I constantly spray her and the other 2 mice with lites/mites spray once in two weeks. This still doesnt help with the thinning of her hair. I tried bathing her - and it didn't help also.

She is active and energetic and no lumps on anywhere! What is wrong with her?

ANSWER: Hi Adrianna,

I'm actually not sure anything is wrong with her at all!  If the problem were mites, the mite spray was well-shaken, and the entire cage cleaned, the spray should have eliminated your problem in just two treatments (and more can be irritating in itself).  Mites also tend to make a mouse very itchy, so she would have scabbing in the areas with missing hair (both a result of scratching).  As far as allergies, it doesn't have to be a food allergy, but could also be a result of an irritating bedding.  You can try switching the bedding out, aspen and Carefresh are good choices (though paper beddings are not necessarily hypoallergenic).  Be aware, however, that with allergies it can take up to a few weeks to see any change once you've altered something in her environment.  Finding allergies takes a great deal of patience!

What I actually suspect is going on is a mouse habit called barbering.  It's not painful, and involves the dominant mouse in a group trimming down the hairs on submissive mice, usually in a set, uniform pattern that's the same each time.  Here's an excellent link to a page on barbering and other causes of hair loss (and pictures!):  http://www.thefunmouse.com/info/hair-loss.cfm  My guess is that when your new mice groom each other, the one with the thinning hair is getting a hair cut!  It isn't a problem, it just looks really weird.  I would only worry if you start to see cuts, bites, scratches, scabbing, or constant redness that would indicate discomfort.  An excellent way to test would be to separate them for a couple of weeks and see if the hair grows back.  Sometimes, though not often, a mouse will overgroom themselves if they are nervous, pulling out hair and irritating the skin.  I don't think this is the case because of the timeline, but you never know, she might not feel comfortable around her cagemates.

Of course, if it actually does bother her, and her ear turns red more and just really bugs you (or her), keep looking for an allergy or consider bringing her to your local vet that works with pocket pets.  You know it isn't anything universal, like something irritating near the cage or in the air, because only one mouse is being affected.  It might be worth it to give your vet a call first and see if they have any ideas - sometimes they'll give you suggestions without making an appointment!

Let me know if you have any more questions, and I hope I helped!
-Tam

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

QUESTION: Hi Tam!

I have got another problem with the same mouse. I have figured out that she is allergic to corn kernels. Lately, (after 4 months of having her) she refuses to eat or drink and only stays in her house whenever she is in her cage. When I take her out of it, she will eat food (like crackers) but still doesnt eat the mouse mixture food or drink water. I have to constantly give her water by hand. She has loss a lot of weight. She has no breathing problem, and only seems to be active when she is out of her cage.

Her poo is black and very small but moist.

Please help!
Thanks
Adi

Answer
Hi again!

I'm glad you found her allergy - they can be pretty tough to pin down!  Try mixing other foods that don't have corn in with her diet, like cheerios, millet sprays, different blocks or corn-free mixes, and maybe some stale bread.  The weight is my biggest concern - if it weren't for that I would wonder if she is just playing, eating, and drinking at night or when you're not watching, but weight loss is not a good sign.  You can help get more moisture into her by soaking chunks of the stale bread in water, and same with the cheerios.

If you are still treating for mites, it may be a good idea to stop, since they don't seem to be the problem.  Stress could cause a difference in behavior, and mite sprays aren't the most fun in the world.  How are the other mice behaving?  Could they be hogging the food or water bottle, or bossing her around?  Perhaps she's uncomfortable around them and is hiding when in her cage?  I would try separating them, but because of the weight, I'd strongly advise a visit to the vet to be sure nothing else is going on.  Bring in the whole cage and all of the mice if you can so he or she can get the whole picture and examine her and the waste for any signs you and I might be missing.

The most important thing is to make sure she's eating and drinking, even if it means separating her from the other mice so she can get her share (I'm only guessing that they were caged together from your first question?).  If there is absolutely no way to bring her by a vet, write me back, but I would strongly urge you to try to get her to a professional simply because I really don't want to miss something that might result in harming your pet.  If you can't find a vet in your area that will see pocket pets, try asking pet shops, animal shelters and sanctuaries, rehabilitators, and even try mouse breeders - if they can't help you they may still be able to point you toward someone who can see your mouse in person and give you hands-on help.

Hope she puts that weight back on soon and feels better!
-Tam