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Mice/bald spot


i've got two male mice and they seemed to have lost hair in between their ears and one of them on the side of his face. i dont know what the problem is. it doesnt seem to be getting worse. i dont really know how it happened and im kinda worried. i would like to know whats wrong and if theres anything i can do about it. i would really like to know what might have caused it. do their hair grow back? though it makes distinguishing them easier, i dont want them to look like that.

Hi Clara,

There are a couple of possibilities.  First, if there is any irritation with the skin, then it is treatable, and the hair may grow back.  Things to look for include redness, scabbing, discharge, swelling, or excessive scratching.  A vet can identify with a simple test in a single visit what the cause is, and how to proceed.  While mites are a frequent cause of itching and resulting hair loss (treatable with a single drop of kitten Revolution on the back of the neck of all exposed mice, as well as a thorough cage cleaning), they are not the ONLY cause, so if you can't see the vet let me know and I'll try to help you eliminate some possibilities and figure out what's going on.

Another potential cause of hair loss could be fighting.  If they live together and you see any bite marks, scuffling, fighting, tail rattling, or defensive posturing (like standing on the back legs and "boxing" outward at an offending mouse), you may need to separate them.  Male mice do not normally live together and can go from friendly to fighting to the death seemingly overnight.  Once separated, they would not be able to be reintroduced to each other.

The last possibility is a common mouse behavior called barbering.  If they live together and are fond of grooming each other, and if the bald spots are NOT irritated, red, scabbed, or swollen, you're probably witnessing this harmless, albeit unattractive, habit.  Barbering is when one mouse (usually the dominant one) nibbles off the hair of another mouse in a certain pattern.  They bite the hair off near the skin, but since they don't pull on it or bite the actual skin, it doesn't cause the other mouse any harm.  Mice will also sometimes cause hair loss to themselves and others by overgrooming, which is just what it sounds like - grooming too much until hair starts falling out.  It can be a sign of stress or just a nervous habit, but it isn't usually harmful.  Either way, if grooming or barbering is to blame, there isn't anything you can do except try to reduce stress in their habitat, but even then, they'll probably continue this weird behavior.



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I can answer questions regarding mice as pets, mouse behavior, color and coat genetics, breeding techniques, and general health questions. I can help with caging and setup, nutrition, social issues, and what to do in most mouse emergencies (such as unplanned litters, injuries, fighting, etc.). I can also assist with questions pertaining to orphaned mouse pups, weaning litters, and questions of mating and birthing. I cannot answer questions about exotic or wild varieties of mice such as spiny or pygmy mice. *****FOR EMERGENCIES, anything requiring immediate medical intervention, PLEASE take your mouse to a professional veterinarian or wildlife rehabilitator who works with mice as soon as possible! IMPORTANT RESOURCES: Raising Orphaned Mice: Orphaned Mice Videos: Natasha's Your First Mouse: General Mouse Help: Mouse Info and Exotic Breeds:


I have enjoyed the companionship of mice nonstop since 2004, and spent a year caring for them in a lab where I learned a great deal about their breeding, social needs, and health. I spent a few years breeding them, specifically working with albinos, marked mice, angora mice, and satins. My education never stopped - I am learning something new every day from current and well-established research thanks to the wonderful folks at the Jackson Laboratory, as well as from my wonderful mousey friends online. I also love learning from my terrific questioners here on AllExperts - you folks keep my passion for these amazing animals alive and well!

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