There is a also painful condition called flystrike that can occur (mostly with outdoor rabbits) that happens when flies lay their eggs in soiled fur (mostly around their bottoms). (petguide.com)
All rabbits should be «rear checked» for flystrike twice a day in the warmer months. (supremepetfoods.com)
And making it a point to keep your rabbit at the ideal weight will also prevent problems like flystrike, which is more common in overweight rabbits who are unable to properly groom themselves. (petguide.com)