Updated November 29, 2020
‘At A Glance (Details Below)’ What To Do
Why Cats Urinate In The House
- The cause is usually anxiety, territorial stress, urinary tract disease or litter box problems
- It’s not bad behaviour; most cats will stop peeing inside if you treat the cause and don’t punish
- Clean up areas with cat urine using enzymatic cleaners to reduce odour and prevent recurrence
Now dive deeper.
If your cat has started urinating in the wrong place, please act quickly. A habit can be very hard to change if it goes on for too long. To fix the problem you need to know why it’s happening…
Why Do Cats Urinate Inside?
The most important thing to understand is that there is always something wrong. There are three broad categories of problems that cause cats to pee inside.
- Urinary Tract Diseases
- Behaviour & Mental Health Problems
- Unsuitable Litter Tray Management
Let’s look deeper at each of these.
Urinary Tract Diseases
Feline Idiopathic Cystitis
Ever had cystitis? If you have you’ll remember the sudden burning need to urinate. FIC can make cats urinate outside of the litter tray and pass small amounts, often with a lot of straining. Sometimes there’s also blood.
Most cats with cystitis don’t have an infection but instead, have this poorly understood disease. If you suspect your cat has pain on urination, read our guide to managing and treating cystitis in cats.
Urinary Tract Infection
There’s no way to tell FIC from true bacterial cystitis without urine testing, which your vet will ask you to collect when needed. I see infections more in elderly cats who don’t have a previous history of urinary problems.
Once common, bladder stones (called urolithiasis) are now a rare cause of urinary problems in cats. Modern cat diets have been adjusted to reduce urine pH so that stones are less likely to form.
When they do, signs look much like for FIC or infection. The exception is the male cat straining to urinate. This can be a true emergency due to bladder stones blocking the urethra.
Any disease that causes problems moving will make it hard for your cat to go to the toilet, especially if outside or in a high-sided litter box.
Read about my old cat’s arthritis here; as well as being less active, she started toileting on the floor until I recognised the problem.
Passing Too Much Urine
Cats normally produce small amounts of urine, but there are many diseases that can change that. When cats are forced to produce large amounts of dilute urine, we often see overflow incontinence.
Why Cats Pee A Lot
Common diseases causing cats to pass more urine include chronic kidney disease, diabetes and thyroid problems. Your vet can find the answer using routine blood and urine testing. Visit this page for more on the diseases causing increased drinking and urination in cats.
Anxiety & Behaviour Problems
Urine in cats is also a tool for territorial marking. Normally a cat won’t mark the core of their territory unless something is wrong. The exception is tomcats (undesexed males) who usually mark the house.
To spray urine the cat stands up, usually making a treading motion with its back feet, quivers its tail and a small amount of urine is sprayed backwards onto a vertical surface such as a wall, leaving an obvious scent mark. Common sites for spraying include doors, windows, around cat flaps, curtains, electrical equipment and shopping or rubbish bags. https://icatcare.org/advice/problem-behaviour/soiling-indoors
I won’t assume a cat is marking until I’ve also proven that the urine is normal. Here are some behavioural reasons why cats may pee in the house.
In my experience, it’s best to assume the cause is another cat, even if you haven’t seen the evidence. Cats are very good at hiding the signs of conflict or stress. Examples could be:
- Acquiring a new cat
- A stray cat (especially tomcats) hanging around outside
- A cat entering via a cat flap to steal food
- A kitten recently matured into an adult
Your cat’s physical and mental health often depends on keeping strange cats away. That includes not allowing cats to look in through the window.
A New Environment
I’ve seen urine marking after renovations or moving into a new house. The new place just doesn’t feel like home anymore. Here are our ideas for making the home more cat-friendly. Minimalist open plan living isn’t how most cats would choose to live!
Cats are very sensitive to their environment, so even changes in people or other pets could trigger urine marking. A common example is a new dog in the house.
If something causes your cat to fear going outside the problem may not be marking at all. Cats may urinate inside simply through the lack of a litter tray option.
If you suspect a behavioural cause, visit our page on treating anxiety and stress in cats.
Litter Tray Management
The fact that cats will pee & poop in a box can make us take this very convenient behaviour for granted. Don’t; it’s precious. Here’s when litter trays don’t work:
Not Enough Litter Trays
Provide at least one per cat unless you are sure your cats don’t mind sharing
The tray needs to be semi-secluded but easy to access. It can’t be where a cat feels watched or under threat from children, dogs or other cats. It also shouldn’t be near food and water if possible.
If your cat is using a spot you don’t like, put a litter tray there for a few weeks until it’s used regularly. Then ’walk’ the litter tray slowly day by day to where you prefer.
Wrong Type Of Litter
The message here is to use whatever your cat likes, or beware! Dry sandy soil seems to be the innate preference but cats should adapt to artificial litters if transitioned slowly. Read more about cat litter choices here. Whichever you use, a deeper layer seems better.
Enclosed litter boxes with lids are all about human convenience. Ammonia can build up to intolerable levels inside these small spaces without us even noticing. Generally, it’s good to use open litter boxes unless you can clean them every day, and an 86cm by 39cm box has been shown to be better than 56cm by 38cm.
Cleaning Too Much Or Not Enough
Yes, both are a problem for some cats! The ideal tray for most cats has a slight toilet smell but no urine or faeces present. I had a cat who would never use a litter tray even twice without cleaning but most can be changed every few days without refusal.
I only scoop or knock out the old litter and replace with fresh so that the tray retains a slight odour. Using chemical cleaners is more likely to put cats off than help them.
How To Clean Up Cat Urine
If your cat keeps peeing in the wrong place, it may be because it still smells like a toilet. Cat urine is detectable by cats long after we can’t smell anything. Here’s how to reduce the odour:
- For fresh urine, start by blotting up as much as you can with paper towel.
- Press the towel onto the stain, throw away and repeat until no urine is soaked up.
- Then you have two options:
- Option 1: lightly wet the area with a dilute mixture of laundry detergent and water. Bio-Zet or other enzyme-based cleaners have always been preferred by vets. Don’t use so much that it carries the urine deeper. Then repeat the blotting until dry again.
- Option 2: a specialised enzymatic cat urine spray such as Urine-Off is probably better. Most of these are sprayed on and allowed to dry before removal using water. Follow the instructions on the product you choose.
- Rest the area by preventing access for a while. This could mean keeping the door shut, covering the ‘toilet’ with furniture, or using bubble wrap or aluminium foil as a deterrent.
Areas often get re-used despite your best efforts. Cats are creatures of habit. Even if you remove the smell, your cat may continue to use an area based on past experience.
How to conclude? By saying the obvious: cats peeing inside isn’t just a simple case of laziness or spite. It’s complicated and they need our understanding. Now spread the word!
Have something to add? Comments are welcome below and will appear within 24 hours.
By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. These help topics are from a series regularly posted on email and Twitter. Subscribe via email here to never miss a story! The information provided here is not intended to be used as a substitute for going to the vet. If your pet is unwell, please seek veterinary attention.