A clean litter box is a happy litter box. Your cat's sense of smell is dramatically more sensitive than a human's- this means that litter boxes that may not smell bad to a human may be offensive to the cat. Cats are fastidious creatures. They evolved in the desert, using sand and soil for elimination of their waste. They prefer to urinate in one location, defecate in another, and eat and sleep in other locations. Many cats have strong preferences as to the type of litter and the type of litter box that they prefer.
Most cats prefer the use of multiple litter boxes, and often urinate in one litter box and defecate in another.
Scooping the litter box daily is important for most cats, especially when clumping litters are used. Clumping litter forms a solid ball of material when in contact with the liquid urine. If scooping daily is neglected, the clump dries out, and soiled litter "declumps" into the clean litter, making it difficult to keep the box clean and allowing odors and bacteria to grow and discouraging the cat from using the box. When clay litters are used, solid wastes should be removed daily and the entire contents of the box discarded and replaced weekly.
When washing the litter box, use hot water and dishwashing liquid. Avoid bleach and strong cleansers as their odors may leave the litter box less attractive to the cat.
Whenever possible, let the litter box dry in the sun outside after washing to aid in freshening the box further.
When using clumping litters, add a little clean litter to the box each time you scoop. This regular replenishment reduces the frequency needed for complete cleaning and replacement to every 2 to 8 weeks, depending on the number of the cats in the household and volume of urine and stool produced. Cats that produce large amounts of urine such as those with diabetes or renal disease or who have diarrhea issues may require more frequent litter box cleaning and litter replacement. Avoid using litter additives such as litter box deodorizers when cats are having litter box issues- these strong smelling deodorizers may repel sensitive cats just as too strong perfume can repel and annoy humans.
Don't expect children or less bonded adult partners to be the individual responsible for litter box care. Many feline elimination problems are caused by inadequate litter box care. The cat does not want to use a filthy box and thus goes elsewhere.
Avoid using mats that are supposed to trap litter particles from being tracked or carried away from the box. Most of these mats have a bristly or coarse surface. This coarse surface is unpleasant for many cats, and they may avoid using the litter box in order to avoid touching that surface. Instead, use a carpet style welcome mat next to the box (not the cocoa leaf varieties with bristles but the soft textured types) to help reduce tracking and clean up.
Some cats urinate over the edge of the box. These cats must not be punished! They are using the box! Instead, try varying the depth of litter from high to low, with the lower area in the corner that the cat urinates if. Sometimes decreasing the depth will keep the urine in the box. In addition, litter boxes with higher walls can help prevent the "over the top" aim of some cats. Plastic clothing storage boxes come in varying depths and can make excellent litter boxes. Boxes with very tall walls can be modified by cutting an entrance area on one side and taping the sharp plastic edges to reduce the chance of cuts. Finally, place a large garbage bag followed by newspaper under the box to effectively absorb any urine spills and make clean up hassle free.