To prevent overgrown nails in rabbits, you can provide a proper diet with enough fiber to encourage natural wear and tear on their nails. Additionally, regularly provide opportunities for exercise, such as running and digging, to help naturally trim their nails. You can also provide safe chew toys to help keep their nails at an appropriate length. Regular nail trims by a veterinarian or a professional groomer can also help prevent overgrown nails in rabbits.