Why Do Cats Spray Indoors?

Spraying is one of your cat’s more extreme methods of claiming territory and can be very frustrating to deal with when it happens inside of the house. Claiming territory through scent marking is very normal behaviour for a cat but they usually do it by rubbing their fur on everything inside of their house including you. Scent marking is necessary for your cat to feel at home and safe. Cats will resort to scent marking through spraying when they really feel the need to claim territory. They may start doing this for a range of behavioural or medical reasons.

Stressed, anxious or threatened cats will begin to spray indoors in order to feel more confident about their living space. Cats don’t do well with change, so it doesn’t take a lot to stress them out. Changes can be as minor as you being outside of the house longer than usual or a new guest visiting. If you can find and remove the source of your cat’s stress you may be able to prevent them from further spraying. 

If your cat has lost control of their bowel movements, you may think that they are spraying. Instead, they could be suffering from a wide range of medical problems. Pain can also cause the stress necessary for them to feel the need to spray. The only way to make sure that there isn’t a medical cause of your cat’s spraying is to take them to a vet. If your cat has begun spraying regularly, we would recommend booking a consultation as soon as possible. Read on through this article for our advice on different behavioural problems that could be causing your cat to spray and ways you can prevent or deter it from happing in your home.

Behavioural reasons your cat could be spraying inside

Spraying is often a response to your cat feeling stressed, anxious, or threatened. Depending on your cat’s temperament it can be easy for them to get into these moods. Recent changes inside of your house or to your routine can be stressful to your cat. Common behavioural causes of cats spraying indoors include new people or animals visiting the household or an animal in the area which your cat can see and smell. Indoor cats can become much more territorial if an outdoor cat begins greeting them at the window.

The cause of stress may also be much less obvious. Your cat may be perceiving something as small as reflected light inside of the house as a threat causing them to become more territorial. Watch your cat throughout the day to see if you can tell if there is a particular sound, sight, or smell which is causing them to behave a bit more defensively. The circumstances casuing your cat to spray will probably be fairly unique so we recommend watching them throughout the day to see if you can identify what could be making them feel threatened in their own home.

As we mentioned earlier, cats can start spraying as a way to release anxiety. A common cause of this is separation anxiety. This can be particularly common with indoor cats that aren’t given enough stimulation. They begin to feel more and more anxious throughout the day while you are gone as they are bored and lonely. When your cat sprays they release some of this anxiety by comforting themselves by claiming territory.  

These cats may also spray on objects that carry your or other unfamiliar scents like clothes, suitcases, and your bed. It can feel like these cats are spraying as a form of revenge when they do this and you may think that they are upset with you. It certainly can seem that cats can hold a grudge against us sometimes but there is no proof that cats exhibit behaviours as complex as seeking revenge. If your cat has begun spraying on your personal belongings, it is much more likely they are acting on feelings of stress than any form of anger or vengeance.

Medical reasons your cat could be spraying indoors

Cats that haven’t been sprayed or neutered are much more likely to spray. Unfixed cats have different levels of hormones which gives them the need to be much more territorial. This is just one of many reasons indoor cats should be spayed and neutered.

Indoor cats suffering from physical pain may start spraying. Senior cats in particular may be suffering from joint pains that can cause this stress. Physical pain may also be making them avoid the litter box if they can’t get in to it comfortably. Spraying due to pain can happen to all ages of cats though, they may have had an awkward fall while playing or something more serious going on inside of their body. Many other medical conditions can be confused with spraying. Common cat illnesses like hyperthyroidism and crystals in their urinary tract can cause your cat to lose control of their bladder. Only a vet will be able to diagnose these conditions properly.

Other reasons your cat may be urinating outside of the litterbox

If your cat is picking a particular place to spray it may be that they are unhappy with the state of their litter box. Cats can be picky when it comes to where they go to the toilet and many things can make them start avoiding their litter box. The most common cause of course being a dirty litter box. Make sure that you are correctly cleaning litter boxes at least once a day making an effort to remove urine soaked cat litter. If you have started using a new cleaning product near the litter box your cat may be finding it overwhelming. We would recommend against

How to stop a cat from spraying indoors

Some owners feel the need to punish their cat when they spray. We and many cat behaviourists would strongly recommend against this. Cats don’t respond to negative reinforcement and won’t understand why you are punishing them. While some blogs have recommended using non harmful tactics like spraying your cat with a light mist of water most of them recognise that doing so is harmful to the relationship between you and your cat. At best, all you are doing is scaring your cat so they stop spraying a single time. At worst you could be making the situation worse as your cat becomes more scared in the house and feels an increased need to mark their territory to alleviate this.  

If you have contacted your vet and have eliminated the possibility of medical causes of spraying, you need to start eliminating behavioural causes for spraying. We’ve gone over some of the most common causes for this but there can be many more and your cat may be stressed by some unique circumstances. At a minimum, we recommend making sure that your cat has spaces in the house to call their own and regular play time with you so they feel confident in the place they live. You may need to watch your cat for some time before you can determine what is causing them to feel stressed in the house.   

This can take some time to do, we understand that you may be after an immediate solution to your cat spraying indoors but unfortunately there isn’t one. There are however, safe ways to repel your cat from spraying in a specific location. Double sticky tape and smells of citrus, mint, or lavender are common things that cats hate. You can place tape on the floor around an area or rub essential oils into the surface of an area you want to protect from your cats spraying. Spraying is a response to fairly severe stress so there isn’t any guarantee that your cat will begin avoiding these areas if they really think they need to claim it. If your cat is spraying indoors it is important that you focus on removing the cause rather than deterrence.

Artificial cat pheromone diffusers may also be enough to make your cat feel happier. There are a couple of brands available for this but Feliway is perhaps the most famous and easily available. You will be able to buy it as a spray or diffuser at your local pet shop or online.

Does the smell of cat spray go away?

Cat spray can smell very strongly of ammonia and is a very unpleasant smell indoors. Unfortunately, the uric acid inside of cat spray can work itself into materials and linger for even years. You should clean at spray as soon as possible when it happens. Use enzymatic cleaners as directed to clean cat spray. You can use a black light to see where the spray has gone and you should avoid spreading it further with exvessive rubbing. If the smell has’t gone the first time you can try cleaning again with more enzymatic cleaners. Cat spray is made up of urine and additional chemicals from your cat, it is designed to stick around and smell strongly. If you weren’t able to clean an area that has been sprayed on proprely the first time the smell may stick around for years.


To summarise, cats spray indoors in response to feelings of anxiety and stress but there could also very easily be medical reasons causing this. If your cat is spraying indoors regularly you need to take them to a visit at the vets. If you are certain that there is no medical cause, you should try to remove the cause of your cat’s stress. This could be any change to their lifestyle causing them to feel threatened. Common causes include outdoor cats meeting  them at the window, new people in the house, and changing schedules. You should also check that your cat’s litter box is clean enough and big enough for them. Punishment is very unlikely to make spraying stop and can easily make it worse. However, you can try to deter your cat from spraying in a specific area with strong smells and souble sided tape. However, you should focus on removing the cause of spraying rather than disciplining or deterring your cat. Indoor spraying is very inconvenient for the owner to deal with but your cat isn’t trying to make more problems for you out of spite or revenge, they just want some way to feel safer in their own house.