Cat Litter Box Problems: Causes for a Cat Peeing Outside the Box

Nov 27, 2010
Lorie Huston

Reasons for Peeing Outside of Cat Litter Box - Lorie Huston

Cats may pee outside of the litter box because of medical problems, spraying behaviors or an aversion to the litter box. Resolution depends on the cause.

Inappropriate urination, or peeing outside of the litter box, is one of the most common complaints made by cat owners. It can also be one of the most difficult problems to deal with or to tolerate in the home.

Causes for a Cat Peeing Outside of the Litter Box

There are three reasons a cat may choose to pee outside of the litter box.

The cat may be suffering from a medical issue that is causing him to pee outside of the litter box.
The cat may be marking his territory. This is more commonly known as urine spraying or urine marking.
The cat may be avoiding the litter box and choosing a more desirable area or substrate to use when he pees.

Resolving the urinary problems will require determining the cause.

Medical Causes for Cat Urine Problems

There are several medical issues that can cause a cat to urinate outside of the litter box. Additional symptoms present will vary depending on the cause but may include:

frequent urges to urinate, often producing only a small amount of urine with each attempt
pain while urinating
bloody urine
increased volumes of urine
increased thirst

If your cat begins urinating outside of the litter box unexpectedly, it is advisable to have a veterinary examination performed to rule out medical issues. Your veterinarian will need to collect a sample of your cat's urine to perform a urinalysis. Routine blood testing may be indicated as well, depending on the situation.

Urine Spraying or Urine Marking as a Reason for a Cat Urinating Outside the Litter Box

Cats use urine to mark their territory in an attempt to let other cats know that they claim the area as their own. This is referred to as urine marking. Urine marking is a communication tool.

Determining whether your cat is marking as opposed to avoiding the litter box can be a difficult task. These are some of the things to keep in mind.

Urine spraying involves urinating on a vertical surface such as a wall. Urine spraying is a form of urine marking and always indicates marking behavior. Not all cats that are marking their territory will pee on a vertical surface though.
Both male and female cats can spray.
Though less common after neutering or spaying, urine marking can still occur in neutered male cats or spayed female cats.
Urine marking may occur in a specific location in the house, such as a near a doorway. However, this is not always the case.
Even cats that live by themselves may still mark their territory with urine. This may be a response to seeing other cats outdoors or to other stimuli.

One of the important things to understand in a situation where the cat is marking is that, to the cat, this is normal cat behavior.

Litter Box Avoidance or Aversion as a Reason for Urinating in the House

Some cats will urinate outside of the litter box in various areas of the house because of an aversion to the litter box. This may arise for many different reasons.

The litter box may not be clean enough.
The litter box may not be big enough.
The sides of the litter box may be too high, especially for an older arthritic cat or a young kitten.
The litter box may be in a location that the cat does not like.
There may not be enough litter boxes available if there is more than one cat in the household.
The litter box may be in a location where the cat is disturbed when using the box.
The cat may not like the type of litter in the box.
The litter box may be too near the feed and water area.
The cat may relate the litter box to an unpleasant experience, especially if the cat has suffered a medical issue that resulted in pain while urinating.

Cats that are avoiding the litter box because of an aversion may choose a specific type of substrate to urinate on, such as bedding, clothing or carpeting. They may choose one or two specific areas in the house in which to urinate.