Causes for inappropriate elimination can range from underlying urinary tract conditions to behavioral concerns. Here are some potential reasons your kitten, adult cat or elderly cat's peeing outside the litter box.

Kittens
Kittens learn what to do by watching their mother. If kittens are orphaned or adopted too early, they may miss out on cat litter box lessons. In these cases, take on the role of a mother cat and teach your kitten to use the litter box appropriately.
Adult Cats
If the behavior is new, you might wonder: Why is my cat not using the litter box anymore? Maybe you recently changed their setup, or perhaps their preferences or needs have changed. Your cat may have a problem with the litter box maintenance, size or location. If you're not scooping and changing the litter regularly or the layer of litter is too shallow or too deep (most cats prefer about 2 inches), they may decide to pee elsewhere. Your cat also may not use the litter box if it's difficult to access or contains a liner that catches their claws.
Some cats like to have separate boxes for solids and liquids. In multicat homes, cats often dislike sharing the facilities. Other cats are wary of litter boxes that don't feel private or quiet enough. Cats also have distinct tastes when it comes to litter scent and texture (most prefer unscented) and may snub the box if you've recently switched to a different type.
Household changes can also increase stress and impact your cat's demeanor. Moving, remodeling, pet or human additions or losses, and even the sudden presence of outdoor cats may raise kitty stress. This can result in hit-or-miss litter box behavior at any age. Stress can also lead to medical urinary conditions, like feline idiopathic cystitis. If you suspect stress, reach out to your vet for advice.
Senior Cats
Do you have an older cat peeing outside the litter box? If your senior cat's peeing outside the litter box after years of using it, it may be due to declining mobility or cognition. In these cases, some cats may associate the litter box with a painful or uncomfortable situation, eventually leading to an aversion.
Signs of an Underlying Health Concern
If your cat has persistent accidents or won't use the litter box at all, it may be a sign of a medical condition, such as feline lower urinary tract disease, bacterial cystitis, kidney failure, liver disease or diabetes. Check for the following signs of medical urinary issues:
- Consistently urinating and/or defecating outside the litter box
- Spraying urine (vertical urine marks around doorways, walls, windows or objects)
- Spending too much time in the litter box
- Visiting the litter box more often than usual
- Vocalizing in the litter box
- Acting lethargic
- Drinking more water
- Eating less
- Losing weight
Your veterinarian can help diagnose and treat a range of underlying health concerns to get your cat back on track.
