It's quite normal for babies or those fairly new to a wheel to get bloody feet. It can happen regardless of the type of wheel unless you are using mesh or a silent spinner which can catch tiny nails and yank them out.
For a solid surface bucket wheel, comfort wheel or flying saucer, usually it is because they run so much the run their tender feet raw. Sometimes they can get stress cracks between the two outside toes, usually on the back feet but not always.
Since there was alot of blood, leave the wheel out for tonight so his feet can heal. Chances are good, it will happen again before his feet toughen up.
For a solid surface bucket wheel, comfort wheel or flying saucer, usually it is because they run so much the run their tender feet raw. Sometimes they can get stress cracks between the two outside toes, usually on the back feet but not always.
Since there was alot of blood, leave the wheel out for tonight so his feet can heal. Chances are good, it will happen again before his feet toughen up.