Rabbits have a natural tendency to want to eliminate in a specific area, so they are surprisingly easy to house train. Watch your rabbit in his cage for a few days and determine where he typically eliminates. This will often be one corner of the cage. Place a litter pan there, filled with the same material that is in his cage.
When you let your rabbit out of his cage for exercise and play time, keep him confined to one room in the beginning. Place litter pans in each corner or anywhere you notice that he tends to eliminate. Don’t yell at or startle your rabbit if he goes outside a litter pan; you’ll only frighten him and make the process harder. Instead, scoop up (or soak up) the waste and place it and the paper towels in one of his litter pans. Having the smell there will help him understand where he’s supposed to go.
You may need to work on this process for several days or more before your rabbit gets the hang of it. Be patient. Some rabbits will catch on very quickly while others will need a little more time. You’ll need to keep several litter boxes available whenever your rabbit is out of his cage.
If his cage isn’t large enough for a litter pan, then his cage is too small and should be replaced. Often starter cages are sold for baby rabbits, but these are not large enough for an adult rabbit. Some rabbits enjoy multi-level cages, and most of these will offer ample room for a litter pan.
As for cage filler, use a paper based product that will not harm your rabbit if he eats it, and he will eat it. Never use cat litter in your rabbit’s litter pan; it can kill him. Keep in mind that anything in the litter box will also be eaten. This is perfectly normal for your rabbit. Some people use grass pellets in the litter pan for this reason. They’re relatively absorbent and, obviously, edible. However, they offer little in the way of odor control and need to be emptied daily.
Let your rabbit out to exercise daily. He needs time out of the cage, and if you fail to do so, he’ll often “forget” his litter box training if caged too long.
You’ll also need to keep his cage and litter boxes clean. Daily cleaning is best for keeping down odor, and your rabbit will be much happier for it. You’ll also find that he’ll not want to use a very dirty litter box, so he may revert to eliminating somewhere you don’t want him to.
If your rabbit does make a mistake, clean it up and place the waste and paper towels in a litter pan to remind him where he should be going. With patience and time, you’ll be able to trust your rabbit to be out of his cage for extended periods, which is better for him and you.