The number one issue with pet cats is litter box problems. This is the main reason cats of all shapes and sizes are either relinquished or turned into outside cats.
FIRST - rule out health issues. Cats with urinary crystals, urinary tract infections, cystitis, and kidney issues will avoid the litter box because urination has become painful.
SECOND - make sure you are not feeding any dry food to your cat. This includes prescription dry foods for urinary tract issues, kidney and bladder issues. Dry food causes dehydration. “Water” is the most important word when considering urinary tract health. Feeding a water-rich diet of canned or raw food is critical for urinary tract health. Feeding dry (water-depleted) food contributes significantly to urinary tract diseases. Cats consume double the amount of water when fed a water-rich diet versus dry food. A cat on dry food simply cannot drink enough water to stay well hydrated. Cats are designed by nature to get most of their water through their diet.
Important Liter Box Protocol:
The single most common reason for a cat’s refusal to use a litter box is because the box is dirty. Scoop the box daily and change the litter every few days to once a week. Litter boxes must be clean and attractive to the fastidious cat. Wash the box when soiled.
Provide one litter box per cat, plus one. This is VERY important! Extra litter boxes are necessary because some cats like to defecate in one and urinate in another. Also, some cats will not use a box that has already been used by another cat.
Choose an open litter box. Many cats don’t like being confined inside a litter box while others are turned off by odors that are trapped inside a covered litter box.
Avoid the mechanical litter boxes. They are not welcoming to most cats.
Make sure the litter is approximately two inches deep.
The litter box must be at least 1/3 longer than the cat. Cat's don't like to be cramped inside the places they defecate and urinate. Most litter boxes sold in pet stores are simply too small. Plastic storage containers make much better litter boxes and come in a variety of fun colors. Get one at least 22 inches long, 16 inches wide and 7 inches high.
Most cats prefer a finely textured litter - like the texture of the sand-like clumping litter. Select a brand with no dust and one that clumps into a firm ball to make scooping easier and cleaner. As a health precaution for kittens that might be prone to ingest the litter, use a non-clumping litter until the kitten is older than four months.
Never use scented litter. Perfumed chemical scents can repel cats.
Place litter boxes in quiet, private places that are easily accessible to the cat.
Don't place the litter boxes side by side - space them at least six feet apart.
Never place the cat's food and water bowls in close proximity of the litter box. Cat's don't want to eat where they defecate, nor do they want to defecate near where they eat.