Why is my cat peeing outside the litter box?

Cats are typically litter box trained and pee inside of a litter box. Sometimes, though, your cat will urinate in another spot- anything from bed to a carpet to a pile of laundry! This is not a typical or desired behavior from cats, and is medically referred to as “Inappropriate Urination”.

The short answer to this question? Unfortunately, there isn’t just one- there is a long list of reasons why a cat may pee outside of the litter box. We will review some of the most common categories here.

1) Litter Box Aversion

This is when a cat does not like their litter box set up and will prefer to urinate and defecate elsewhere. There can be a number of factors affecting their tolerance including: litter box size, depth of litter, type of litter, location of box, and frequency of cleaning.

Studies show that most cats prefer the following:

  • More than 1 litter box per cat – ideally, the number of litter boxes equals the number of cats + 1
  • A large, open, uncovered box that they can easily turn around in
  • 4-6 inches of litter on the bottom
  • Clay, clumping, unscented litter
  • Boxes placed in a quiet and low-traffic area that is easily accessible
  • Boxes placed in different locations
  • Having the box scooped once daily and having the litter totally changed out once weekly

Not all cats want or need all of these factors, and preferences can vary. However, if your litter box setup does not include all of the above and your cat is urinating outside of the box, consider changing it.

2) A Medical Condition

This is a very broad category, but cats who are feeling sick for any reason may start to urinate outside of the litter box. It could be a condition that directly affects their urinary system, or it could even be something that makes squatting painful like arthritis. So many medical conditions are possible, but here are some of the more common ones we see:

  • A urinary tract infection
  • Urinary stones
  • Kidney disease
  • Diabetes
  • Arthritis

3) A Behavioral condition

Just like medical conditions, a variety of behavioral conditions can cause a cat to either feel anxious about their litter box or in general. A common one is generalized anxiety. Cats with anxiety may pee outside of the litter box when they feel stressed, but also may be predisposed to litter box aversion as described above.

One specific behavioral condition is called “Feline Idiopathic Cystitis (FIC)”. This is a process where anxiety and stress causes inflammation in a cat’s bladder, which leads to pain when urinating, and can lead to peeing outside the box. Other signs include frequent litter box visits, straining in the box, and vocalizing while urinating. This condition is not well understood, but cats who are anxious are more prone to it. It can lead to such severe inflammation that a cat- particularly male cats- cannot urinate at all, which is an emergency. If your cat is displaying any signs similar to FIC, have them immediately evaluated by a veterinarian.

Other behavioral conditions can include complex interactions between different cats or different pets in the household, such as another cat guarding litter boxes.

As you can see, there are a wide variety of reasons why a cat may urinate outside of the litter box. A detailed history including litter box care, other pets in the household, any potential changes or stressors in the environment, and any medical conditions is key to help guide a diagnosis and next steps for your cat. In addition, blood and urine testing is often needed to rule out medical conditions such as UTIs and stones. There is not a specific test for anxiety or conditions like FIC, but once other conditions are ruled out they can be better diagnosed.