Last Updated: 18/02/2026
Why is my Cat Pooing Outside the Litter Tray?
Is your cat pooing next to the litter tray? Discover common medical and behavioural causes for inappropriate defecation. From the "N + 1" rule to enzymatic cleaners, learn how to create the perfect bathroom setup to keep your cat and floors happy.
Author: Dr Gillian Hill BVSc (Hons)
Reading Time: 7 minutes - short read
It is a situation that can test the patience of even the most devoted pet parent: finding an unwanted "gift" on the carpet right next to a perfectly placed litter tray. While it is easy to feel frustrated, this behaviour is rarely an act of spite. Instead, it is usually a feline SOS - a clear sign that something about their bathroom environment, physical health, or stress levels isn't quite right. By looking at the world through a cat's eyes, the mystery of why they are dodging the box becomes much easier to solve.
Identifying underlying medical causes
In many cases, inappropriate defaecation outside the litter tray (also called 'middening') is linked to underlying medical issues, including:
- Gastrointestinal illnesses such as Inflammatory Bowel Disease, food allergies, anal gland issues and intestinal parasites
- Musculoskeletal discomfort from conditions such as arthritis, which can make posturing to defaecate in the litter tray painful
- Pain: Cats may also avoid the litter tray for defaecation if they associate it with pain originating from other conditions such as constipation or urinary tract disease.
If this is an ongoing issue, a visit to the veterinarian is the essential first step. A physical examination and further investigation can ensure there isn't a hidden health reason for this change in behaviour.
Cats urinating outside the litter tray is a much more common issue, which you can read about in Inappropriate Urination in Cats and Why Do Cats Pee on Things?
Behavioural reasons for inappropriate defaecation
If medical causes have been ruled out, behavioural reasons for the inappropriate defaecation are likely.
Behavioural reasons include:
- Substrate preference issues: When a cat poos specifically beside the tray rather than elsewhere in the house, it often points to a substrate preference issue. The cat knows where they are supposed to go (the location), but they dislike the feel of the litter on their paws (the substrate). They might find the granules too sharp, too scented, or perhaps too dusty.
- Location preference issues: If your cat is choosing a spot far away from their tray, the location itself might be the issue. Cats value their privacy and safety while "doing their business." A tray placed near a noisy washing machine, in a high-traffic hallway, or in a spot where they could be cornered by another pet can make them feel too vulnerable to settle. To a cat, a quiet, low-traffic area with a clear exit strategy is always the preferred choice.
- Cleanliness issues: Cats are fastidiously clean creatures, and many will refuse to use the litter tray if it is not perfectly clean.
- Tray type & size issues: Some cats may not like the type of litter tray or box - some cats may be frightened or frustrated by covered litter trays, whilst others like the privacy provided by them and dislike an open tray. Litter boxes that are too small can make is uncomfortable for cats to trun around or adequately cover their stools.
- Inadequate number of trays: Ideally, there should be one more litter tray than the number of cats in the household. For a single-cat home, two trays are recommended.
- Social anxiety: There can be many inciting causes of social anxiety in cats, discouraging them from using the tray. They may have been cornered by another cat previously and developed a negative association with the litter tray. Changes in the household, new pets or neighbourhood pets hnging around outside can all put them off using the tray.
Cats can develop a preference to urinate in one box and defaecate in another, which is why having multiple litter boxes in different locations is very important.
Litter tray hygiene and "The Gold Standard" setup
Here are the key strategies to address common litter tray issues and ensure your cat feels comfortable and secure.
Substrate preference issues
- The touch test: Offer a "litter cafeteria." Place two trays side-by-side with different textures (e.g., one with fine sandy clumps and one with recycled paper pellets) to see which your cat prefers.
- Go unscented: Many cats find heavy floral or "fresh linen" scents overwhelming. Stick to unscented, low-dust varieties.
- Depth matters: Most cats prefer a litter depth of about 3cm to 5cm - enough to dig, but not so deep they feel like they are sinking in quicksand.
Learn more our Complete Guide to Cat Litter.
Location preference issues
- Privacy and exits: Place trays in quiet corners where the cat has a clear line of sight to see anyone approaching. Avoid "traps" like cupboards where another pet could block the only exit.
- Separate the essentials: Never place litter trays near food and water bowls. In the wild, cats instinctively eliminate away from their resources to avoid contamination.
- Multiple levels: In multi-storey homes, ensure there is at least one tray on every level so your cat doesn't have to travel too far when nature calls.
Cleanliness issues
- Scoop daily: Aim to scoop out clumps and waste at least twice a day.
- The deep clean: Completely empty the tray and wash it with warm water and mild, unscented soap every 1 to 2 weeks. Avoid harsh chemicals like bleach which can leave a lingering scent.
- Replace the tray: Over time, plastic trays develop tiny scratches that trap odours. Replace the physical plastic box every 12 months.
Learn more about How Often to Replace Cat Litter and How to Stop Cat Litter from Smelling.
Tray type and size issues
The physical box must accommodate your cat's natural movements.
- Size it up: A tray should be at least 1.5 times the length of your cat (from nose to base of tail). They need enough room to enter, turn around, and dig without hitting the sides.
- Covered vs open: While we might like the look of a hooded box, many cats find them smelly and cramped.
- Accessibility: For senior cats or those with arthritis, ensure the entry point is low enough that they don't have to "jump" or strain to get inside.
Learn more in our guide to the Best Cat Litter Boxes and the Best Self-Cleaning Litter Boxes.
Inadequate number of trays
The most common mistake is not having enough facilities.
- The "N + 1" rule: Always provide one more tray than the number of cats you have. For example, 1 cat = 2 trays, 2 cats = 3 trays etc.
- Spread them out: Three trays lined up in a row in the laundry only count as "one" location to a cat. Distribute them throughout the house to prevent "resource guarding" by other pets.
Cleaning techniques to prevent repeat offences
Removing the odour of previous accidents is crucial. If a cat can still smell their scent in a specific spot, they are likely to return to it.
- Avoid ammonia: Never use ammonia-based cleaners, as ammonia is a component of urine and can actually attract the cat back to the spot.
- Avoid vinegar and perfumes: Strong scents can overstimulate a cat and may trigger further marking.
- Use enzymatic cleaners: Use a biological soap (like Sunlight liquid or Omo) followed by an enzymatic cleaner such as CSI Urine Cat Stain and Odour Remover. These products break down the odour rather than just masking it.
Managing social anxiety and environmental stress
Feliway
Social anxiety is a very common driver for house soiling. Changes in the household, new pets, or outdoor "intruder" cats can make a cat feel insecure.
Using a synthetic pheromone like Feliway near the litter trays can be very beneficial. This is a man-made version of the odourless pheromones cats leave when they rub against objects. It signals to the cat that the area is safe and secure, helping to lower overall stress levels.
Learn more in our guides to How to Reduce Anxiety in Cats and How to Manage Multi-Cat Households.
FAQs
Solving "out of box" experiences requires a mix of veterinary insight and environmental tweaks. Once medical concerns are ruled out, focusing on the "Gold Standard" of hygiene and substrate preference usually does the trick. Remember, a happy cat is a predictable cat, and with a few small changes to their routine and some targeted cleaning, the laundry floor can return to being just a floor once again.
Articles recommended for you
Our vet authored guide to the benefits of feeding your dog fresh food plus tips and advice for introducing it into their regular menu.
See our guide to protecting your pet from parasites from our vet team.
Thinking of getting a fish? Check out our guide for setting up a tank and home care tips!
Looking to understand horse feeds better? This comprehensive guide covers feeding recommendations for horses of all ages and disciplines.
Does your pet suffer from anxiety? Check out our Vet-guide for treatment options to help your pet.
History
Our experts continually monitor the health and wellness space and we update our articles when new information becomes available.
Thu 19 Feb 2026
Written by Dr Gillian Hill BVSc (Hons)Dr Gillian Hill BVSc (Hons)
Veterinarian
Dr. Gillian loves being able to provide depth and detail to pet parents questions, and give up to date, evidence based advice. She loves the variety of pets and inquiries she receives - she especially loves the 'curly' questions that require some research! Seeing the gorgeous photos that pet parents send through of their babies is a highlight of the day! Gillian enjoys to further her veterinary knowledge, and has completed further training in ultrasonography, behaviour and backyard poultry!
