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Why Is My Cat Spraying Indoors? Causes and Solutions

Urine spraying — when a cat backs up to a vertical surface and deposits small amounts of urine while treading with their hind feet and quivering their tail — is one of the most distressing behaviours for UK cat owners to deal with. It is also one of the most common reasons cats are surrendered to rescue centres. Understanding why cats spray is the first step to finding an effective solution.

Spraying vs Normal Urination: Understanding the Difference

Urine spraying is a communication behaviour, distinct from normal urination. Normal urination involves squatting on a horizontal surface and depositing a significant volume of urine, typically in a litter tray. Spraying involves backing up to a vertical surface, holding the tail erect (sometimes quivering), and depositing small amounts of urine at nose height for other cats.

Spraying is a scent-marking behaviour — the cat is depositing information about their presence, identity and reproductive status for other cats (and themselves). Both male and female cats spray, although intact males spray most frequently and with the most pungent urine.

If you are unsure whether your cat is spraying or has a litter tray problem, the location matters: spray marks appear on vertical surfaces such as walls, door frames, curtains and furniture legs at cat nose height. Inappropriate urination on horizontal surfaces (floors, laundry, bath mats) is a different problem, often with different causes.

Why Cats Spray Indoors

The most common triggers for indoor spraying in UK cats include: anxiety about the presence of other cats (whether resident or visible through windows); changes in the home environment (new furniture, new people, home renovation); social conflict between cats in a multi-cat household; changes in routine; moving home; the presence of in-season cats or intact tom cats in the neighbourhood; and general anxiety or stress.

Cats in the UK are increasingly being kept indoors, which intensifies territorial stress when they can see or smell neighbourhood cats through windows or cat flaps without being able to patrol and mark their territory outdoors normally.

A sudden increase in spraying in a previously non-spraying cat warrants a vet visit to rule out lower urinary tract disease (FLUTD) — cats with urethral discomfort may spray as part of pain-related behaviour change.

Neutering: The Most Effective Intervention

For intact cats, neutering is the single most effective intervention for reducing spraying. Neutering intact males reduces spraying in approximately 90% of cases. Neutering females removes the hormonal cycle that triggers spraying around oestrus. In the UK, cat neutering costs £79–£89 for male castration and £103–£156 for female spay at most practices.

For neutered cats that spray, the hormonal component is absent, meaning the behaviour is entirely driven by anxiety, stress or learned territorial marking. This requires a different approach — neutering an already-neutered cat is not an option, and the focus shifts to identifying and reducing the anxiety trigger.

If neutering is planned but not yet done, and spraying is occurring, booking the neutering appointment promptly is the priority action.

Environmental Management

For neutered cats spraying due to anxiety, the most impactful changes involve addressing the trigger and using pheromone support. FELIWAY Classic diffusers (synthetic analogue of the feline facial pheromone) have clinical evidence supporting their use for reducing spraying behaviour in anxious cats. Place them in the rooms where spraying is most frequent — they take 3–4 weeks to reach full effect and should be used consistently.

If outdoor cats are triggering the spraying, prevent your cat from seeing them by using frosted window film on lower window panes, blocking cat flap access in areas where neighbourhood cats intrude, and ensuring your garden is as secure as possible from visiting cats.

For sprayed areas inside the home: clean thoroughly with an enzymatic cleaner, not ammonia-based products (ammonia smells similar to urine and can attract remarking). Cleaning with an enzymatic cleaner then placing the cat's food bowl or a scratching post over the cleaned spot can redirect the cat's interaction with that area from spraying to feeding or scratching.

Medical and Veterinary Options

For persistent spraying in anxious neutered cats, veterinary options include anxiolytic medication. Clomipramine and buspirone have evidence for reducing spraying in cats, and in some cases your vet may prescribe a short course alongside environmental management.

A specific feline urine marking supplement (Zylkène — a hydrolysed milk protein supplement with calming properties) can be used alongside FELIWAY for some cats and has a reasonable evidence base for anxiety reduction.

In complex cases — particularly in multi-cat households where social dynamics are the root cause — referral to a feline behaviourist is the most effective route. A behaviourist can assess the household structure, identify the specific cats and areas involved, and design a targeted management plan.

Find a Vet Near You

If your cat is spraying and has not been neutered, booking a neutering appointment is the priority. For neutered cats that spray, a vet visit can rule out medical causes and discuss management options. UK consultations average £61.99.

Compare vet prices near you at [CompareMyVet](https://app.comparemyvet.uk) to find a practice with transparent, fair fees for feline health consultations.