A neighbour’s cat is spraying your patio. What now?
Keeping a visiting cat away gets more complicated when your own cat uses the same patio.
Spraying or peeing?
A spraying cat backs up to something upright, like a wall, a door frame, a planter or the barbecue, lifts a quivering tail and leaves a small squirt. It’s a territorial message to other cats, including yours. A cat that squats and digs in soft soil is using your planter as a litter box instead. That’s a different fix: cover the soil, as in our stray cats guide.
Find every spot
Your nose finds the worst one; the cat knows them all. Dried urine glows under a UV flashlight, so go out after dark and check door frames, pot bases, corners and railing posts. Mark each spot with a bit of tape so you clean them all.
Clean it properly
Blot up what you can, then soak the spot with an enzyme cleaner made for cat urine and follow the label. Enzymes break the smell down instead of covering it. Let it dry before pets walk on it. Skip ammonia and vinegar: urine contains ammonia, so an ammonia cleaner can draw the cat straight back. No enzyme cleaner at hand? A 10% solution of biological washing powder, rinsed off well, is the fallback. Bare wood and concrete soak urine up, so plan on two or three rounds.
Make the spot awkward
Cats mark where they walk and linger. Lay plastic prickle mats along the ledge or railing they use and around the base of planters: they’re blunt, but cats dislike stepping on them. Move the pot they always target. If they arrive from a neighbouring balcony or over a fence, ask your building or neighbour about closing the gap.
Talk to the owner
Describe the spot and the time, not the cat. An unneutered tom is the usual sprayer, and neutering fixes most marking. If both cats go out, agreeing on different outdoor times can help too.
Look after your own cat
A stranger staring through the patio door is stressful, and a stressed cat may start spraying indoors. International Cat Care suggests covering the lower part of the glass with frosted film or cardboard so your cat can’t see the visitor.
The trouble with cat deterrents
Motion sprinklers and ultrasonic repellers react to any cat that walks by. In a study of suburban gardens in Perth, ultrasonic devices roughly halved visits by local cats, but didn’t stop all of them. The catch on a shared patio: your cat hears the ultrasound and gets the soaking too. So either run them only while your cat is indoors, or use something that can tell the two cats apart.
What to buy
| Item | What it’s for | What to look for |
|---|---|---|
| UV flashlight | Finding dried marks after dark | A 365 nm LED; it shows dried urine better than cheaper 395 nm ones |
| Enzyme cleaner for cat urine | Removing the smell, not hiding it; pick one safe for outdoor surfaces | “Enzymatic” on the label and safe for outdoor wood or concrete; no ammonia |
| Cat prickle mats | Ledges, railings and the base of planters | Flexible plastic with blunt spikes that you can cut to size; never metal spikes |
| Frosted window film | The lower half of the patio door, so your cat can’t see the visitor | Static-cling film that peels off without residue, good for rentals |
| Motion sprinkler | Yards with a hose, and only when your cat stays in | Adjustable range and a day/night setting; it needs a garden hose |
Sources
- International Cat Care: urine spraying in cats describes the spraying posture, enzyme and washing-powder cleaning, and blocking the view of outside cats.
- ASPCA: urine marking in cats recommends enzymatic cleaners and explains why ammonia-based cleaners draw cats back.
- Humane World for Animals: removing pet stains and odours advises against ammonia and vinegar on marked spots.
- Cats Protection: keeping cats out covers removing food and humane barriers; their advice on cat conflict suggests agreeing on different outdoor times.
- Crawford et al. (2018): ultrasonic deterrents reduce nuisance cat activity on suburban properties found fewer, shorter visits by resident cats, but not by all cats.