There’s a moment every cat owner dreads. You’re tidying up, minding your own business, when you suddenly spot — or worse, step in — a suspicious puddle. It’s not on the litter tray. It’s on your rug, your duvet, or behind the TV. And the big question begins to buzz: Why is my cat doing this?
As someone who’s bred cats for decades, judged at GCCF shows, and worked with countless owners on litter problems, I’ll tell you what I tell everyone: before you start tweaking trays or changing litters, always check for a medical issue first.
It’s the one thing too many people overlook, and it’s often the key to solving the whole mess — quite literally.
When Pee Problems Are Really Pain Problems
Cats are notoriously stoic. A dog will limp, cry, or go full dramatic over a stubbed toe. A cat? They’ll suffer in silence — and often the only sign they’re in pain is a change in toilet behaviour.
Inappropriate urination is a massive red flag for underlying health issues. If your cat’s peeing outside the tray, it might not be behavioural at all. It might be because it hurts to use the tray, and they’re associating it with discomfort.
And guess what? Once pain becomes linked to the tray, even if the medical issue resolves, the habit can stick around.
This is exactly why I wrote Stop Cats Peeing: The Smart, Humorous Guide to Solving Inappropriate Urination in Pet Cats. It helps you figure out not just how to fix the problem — but whether you should be calling the vet first.
The Usual Medical Suspects (And a Few Sneaky Ones)
Let’s break down the most common health conditions that lead to cats peeing outside the litter tray.
1. Feline Lower Urinary Tract Disease (FLUTD)
This is the big one. FLUTD is a catch-all term for a group of conditions affecting the bladder and urethra, and it’s especially common in young to middle-aged cats.
Symptoms include:
Straining to urinate
Frequent trips to the tray
Crying in pain
Blood in the urine
Peeing in odd places
Licking around the genitals
One of the worst variants of this is a urethral blockage, especially in male cats. This is a genuine emergency and can be fatal within 24–48 hours if left untreated. If your male cat is in and out of the tray, trying to pee but nothing’s coming out, drop everything and go to the vet. Now.
2. Bladder Stones and Crystals
Tiny mineral deposits can form in the bladder or urethra, causing irritation and pain. Cats with stones often urinate in small amounts, and again — they may avoid the tray because it’s become associated with discomfort.
One of my breeding girls once developed struvite crystals during a heatwave because she wasn’t drinking enough. We caught it early, but it taught me never to assume it’s “just behavioural”.
3. Cystitis (Inflammation of the Bladder)
Cystitis can be triggered by stress, infection, or diet. In some cases, no infection is found — just inflammation, known as idiopathic cystitis. These cats will often pee in odd places, like sinks, baths, or cool hard floors.
And here’s the kicker: idiopathic cystitis often flares during stressful periods — moving house, fireworks, new pets. Which brings us to a rather inconvenient truth: sometimes it’s medical and behavioural.
Related article: [Stress, Territory, and the Power of Pee] – stress isn't just a mental state; it can trigger physical illness in your cat.
4. Kidney Disease
Chronic kidney disease is sadly common in older cats. The kidneys become less efficient, which leads to increased thirst and urination. Your cat may simply not be able to hold it anymore, or they might not make it to the tray in time.
If your cat is drinking more than usual, losing weight, or seems listless — ask your vet to run bloods and a urinalysis.
5. Arthritis and Mobility Issues
Older cats may want to use the litter tray but find it painful to climb in and out. If the tray has high sides or is placed somewhere that involves jumping or stairs, it might be too much effort.
The result? Peeing somewhere easier. Like your carpet. Or that conveniently-placed cardboard box you meant to recycle.
6. Diabetes
Increased urination is a hallmark symptom of feline diabetes. Cats with diabetes also tend to drink a lot more and may seem hungrier than usual while losing weight.
If your cat is peeing more than usual, especially in volume rather than frequency, it’s time to talk to your vet.
7. Cognitive Dysfunction in Older Cats
Senior cats can develop a kind of feline dementia. They may forget where the tray is, forget how to use it, or become disoriented.
They might also become anxious, which can lead to both stress and bladder issues. I’ve worked with cats who started toileting in corners or behind curtains simply because they forgot the rules.
Related article: [When It’s Time to Call the Vet] – it’s not always obvious when medical intervention is needed. This piece helps you decide.
How to Tell If It’s Medical
You don’t need to be a vet to spot when something’s off. Here are some tell-tale signs that your cat needs a check-up:
Peeing more often, or in greater volume
Peeing less often, with signs of straining
Blood-tinged urine
Crying or vocalising in or near the tray
Excessive grooming of their genitals
Sudden weight loss
Increased thirst
Peeing in front of you (many cats do this as a cry for help)
If you see any of these — particularly straining or vocalising — don’t delay. Book that vet appointment. And be ready to share a urine sample if you can manage it (ask your vet for non-absorbent litter).
Even After Treatment, Behavioural Help Might Still Be Needed
Here’s the frustrating bit: sometimes, even once the medical issue is treated, the peeing continues.
Why? Because your cat now associates the tray with pain. It’s a classic case of negative reinforcement. You can’t just expect them to bounce back.
That’s where behavioural work comes in — gently reintroducing the tray, changing the environment, and building back that litter confidence.
And yes, I go through all of that in Stop Cats Peeing: The Smart, Humorous Guide to Solving Inappropriate Urination in Pet Cats — because medical and behavioural issues are often two sides of the same soggy coin.
Final Thought: A Vet Visit Now Saves You Weeks of Stress Later
If I could wave a magic wand and get cat owners to do one thing before they try all the “quick fixes”, it would be this: rule out medical causes early. It’s cheaper, easier, and less frustrating than trying to fix what isn’t purely behavioural.
Once you know your cat is healthy, you can move forward with confidence — and a solid plan that actually works.
Stop Cats Peeing: The Smart, Humorous Guide to Solving Inappropriate Urination in Pet Cats
By Ross Davies – Certified Feline Behaviourist