By Dr. Stephanie Janeczko, D.V.M., Medical Director for Animal Care & Control of New York City
Some cats don’t mind litter boxes in general, but they just don’t like theirs - often because it is too small or because it is covered. It’s like that pair of pants that has gotten uncomfortably small - you keep trying to squeeze into it although it’s an unpleasant experience, until you finally decide it’s not worth it and just give up.
Most cats, particularly our larger or more overweight friends, cannot comfortably fit in or maneuver in a commercial litter box. The high sides may also make it difficult for older cats or those with arthritis to get in and out of the box. A good, inexpensive alternative is to purchase a plastic container used for under-the-bed storage - these are big enough to allow cats to comfortably obtain in, dig a hole, and then cover up their business.
As a general rule of thumb, the litter box should be at least one and half times the length of the cat. If you’re unsure, you should pick the bigger size.
People like covered litter boxes for the exact reason that many cats dislike them - they keep odors in! You may be able to avoid this problem with diligent scooping and cleaning, but most cats still prefer an uncovered option to the cave-style litter box.