Concerned about Safety of Wheel...

Question
After being very apprehensive about exercise wheels, but feeling like a safe one would be a nice thing for each of my mice to have, I recently, got my mouse, Draco one of the 4-and-a-half-inch Super Pet "Silent Spinner" wheels, and was delighted to see that D was using it after just a few days.  However, the other day, D lost control, and fell out of it a few times--once hitting his/her head (not certain of Draco's gender--hence the dual pronouns).  I considered taking the wheel out and switching it for a different style that one of my other mice has and hasn't used, but saw that D was really enjoying it, so felt bad.  However, tonight, as she/he was using it, Draco gained too much momentum, and went flying out of the wheel flipping at least twice in the air, and hitting her/his head at least one to three times on the wheel and/or aquarium glass as it happened. :-(  Now, I am very worried about Draco (Draco is very active, and flips and jumps around a lot, but I worry because D is about a year-and-a-half old or older, and because I've never seen her/him hit her/his head before. :-|  How can I tell if Draco is injured?!...And, are those wheels unsafe?!  I feel sort of like a heel removing something that my little one enjoys, but don't want to leave something in there that could cause her/him harm (and worry that that might, already be the case, after I elected not to remove the wheel the other day :-\).  If you could let me know of any safety issues that you know of with those wheels (I did see online that someone else posted about a similar problem with a hamster not being able to stay in control of the wheel, as they gain too much speed and are slippery :-|), and what to keep an eye out for to see if there is a problem (and how resilient or fragile mice are when it comes to their own acrobatics and such), and what the critical period of observation would be to see if there's a problem, that might help put me somewhat at ease, or know if I should be as worried as I am.  I hope that Draco wasn't hurt, but am worried, and keep seeing and hearing that terrible wheel flipping thing over and over in my head. :-\

Answer
Hi Kristin,

Wheels are a great way to provide exercise and entertainment, and I'm very sorry your experience with them was so scary!  There are other things you can do to keep them active, however, so it's completely okay to take it away for the sake of safety.

I have personally never had a problem with the silent spinner and have not heard of any safety concerns, but if it's moving too quickly you may see if it's possible to tighten the attachment to the wheel so it has a little more friction.  They should never fly out of the wheel!  That's a definite concern, and something I've never seen happen.  The only time I caution about the use of wheels is with very young mice, who just don't have the weight necessary to use them safely.  If it's a risk, remove it.  Better safe than sorry!

If you're crafty, you can make ever-changing and easy-to-replace playgrounds for them out of popsicle sticks and hot glue, pvc pipe sections, tissue boxes with the plastic removed, and paper towel tubes.  These kinds of toys and "houses" should be thrown out once soiled, and keep them excited, entertained, and exploring.  Plus, they're fun to make!  Some inspiration:  http://www.fancymicebreeders.com/mousefancierforum/phpBB3/viewtopic.php?f=6&t=11

Now, as far as potential injuries, just keep an eye out for balance problems, different behavior like lethargy, and normal grooming and movement.  I really think that if you were going to see any signs of injury that you'd notice them pretty immediately, but I would give it a day or two just in case.  Unless someone gets a little wobbly or stops eating - please don't worry!  Like you said, they're pretty acrobatic, and while bopping their head isn't ideal, it's very likely that Draco is just fine and excited to get back to flipping and hopping around!

Let me know how he's doing!  Best wishes to the little guy/girl!
-Tam