Q: My mouse (2.5 years old, black, female) started rolling this morning. She started losing hair a few months ago; I assumed it was due to age. She hasn’t been running on her wheel very often, and this morning she started rolling. She can’t stand, and it looked like a stroke of some sort at first, but now I see that all her legs are working, just not coordinating. I have spent all day on the Internet looking for an explanation; the closest thing I can find is mites, but she doesn’t appear itchy. I have no idea what it could be. It’s like an alligator death roll. It’s scary. What should I do?
A: It may be that the hair loss is not connected to the neurologic signs you are describing. You are to be congratulated for keeping such good care of your mouse to have it live so long. To have a pet mouse live for two and a half years is a great accomplishment, but with older age comes diseases common in older age. In mice and rats, cancer is a common condition as these pets grow older.
When a mouse is rolling and cannot stand and then appears uncoordinated as yours does, the most common area of disease is in the vestibular system located in different areas of the nervous system. The vestibular system consists of three areas: sections of the brain, nerves that come directly off of the brain, and areas in the ear. It can take a very exacting physical examination and further testing such as a CT or MRI to decide what part of the vestibular system is affected. Obviously, much of this is not going to be possible on your pet mouse.
No matter what part of the vestibular system is affected, the common causes of disease in this area are cancer, infection and toxin exposure. Because cancer might be impossible to treat in your pet mouse and if you are certain that there is no toxin exposure, you might want to try to treat your mouse with medication for infection, because it is something we can treat. Your veterinarian, therefore, might decide to use an antibiotic to help your mouse if this is an infection.
No matter what the cause, your veterinarian may also prescribe a pain medication and another medication to prevent the rolling you are seeing.
Finally, while your mouse is feeling so bad, she is probably not eating or drinking well enough, so your veterinarian may give some fluids and calories to help your mouse feel better.