Indoor Marking - Cat

From WikiVet English
Jump to navigation Jump to search


Indoor marking and housesoiling/inappropriate elimination often occur together in the same household, and in a multi-cat household several cats may be involved. Common factors are discussed on the housesoiling page. An important part of reaching a behavioural diagnosis must be to identify the culprits.

More than one cat may be involved, and it should be remembered that, in some cases, the culprit for indoor marking may not be a resident cat at all. Intact male cats and despots may enter the homes of other cats to obtain food or shelter, or to oust the resident cat. They may then leave urine spray marks within the home. In these cases, treating the resident cats will have no effect on the marking behaviour and, in fact, increasing the level of resources available within the home may raise its value and therefore encourage the invading cat to enter more frequently or try to take over the territory. It is also important to remember that neutered male and female cats spray mark at around the same frequency, so the sex of cats in a household is not a reliable means to identify the culprit.

Due to the high cat population density in many areas, and the high frequency of reported incidents of home invasion by no resident cats, it is generally advisable for all cat owners to use a microchip controlled cat door to prevent other cats from entering the home. It is important to realise that non-resident cats may enter a home and deposit spray marks.

Claw marking may also be involved as part of the indoor marking behaviour.

Typical Causes

  • Stress due to environmental change.
  • Stress due to changes in the owner's routine.
  • Conflict for resources with other resident cats.
  • Loss of existing facial or flank marks in the home: Usually due to redecoration or change of house.
  • Loss of maintenance of group odour: Temporary or permanent loss of a social facilitator cat, absence of the owner, or housing of group members apart (at a cattery at at the vet clinic) so that odour is not mixed between individuals and factions.
  • Failure of odour recognition of a specific individual: Individual odour may be altered or lost if a cat is taken away for grooming or veterinary treatment such as dental work. The cat may even return home carrying the odour of an unfamiliar cat on it. Failure of odour recognition can lead the returning cat to be regarded as an intruder by the other residents. The resulting aggression may prevent the cat from regaining its role in the social group.
  • Introduction of a new cat: This may exceed the population that can be supported by existing resources, or the new cat may upset existing social relationships (through despotism, competition for resources or by increasing stress in the group). The same effect is may be seen when a recently introduced kitten reaches maturity and becomes a potential competitor for resources.
  • Illness: Conditions that alter the cat’s emotional state or interaction with other cats (hyperthyroidism, senility, pain, hyperaesthesia, debilitation) or need for resources (conditions causing polydipsia or polyphagia).
  • Excessive population density outside the home: In areas where there is already a high population density of cats this can restrict resident cat's ability to use outdoor resources, and brings non-resident cats close to the home. Resident cats will use spray marking in an attempt to maintain distance from other cats that they see around their territory.
  • Home invasion by non-resident cats (often entering the home to gain food or shelter)
  • Unfamiliar odours brought into the house: Non-resident cats may spray close to a front or garage door so that this odour can come into the house; owner’s shoes, clothing or bags may pick up odours from outside.


Example of a diagram illustrating the relationships between cats within the same household

Investigation involves several steps:

It is important to establish the motivation of the behaviour to be able to resolve the issue successfully. Scent is used to identify territories as well as individuals and scent marking forms a part of normal cat behaviour; it becomes problematic to owners when inappropriate surfaces and locations are chosen by the cat.

The two main scenarios leading to indoor marking are conflict with non-resident cats, and conflict with resident cats. In an ideal situation, resident cats treat the boundary of the home as the boundary of their core territory. They leave facial and flank scent marks indoors, and use claw and spray marks only outdoors. If the core territory is threatened by being overlooked or invaded by cats that are not part of the group, then the boundary of the core territory can retreat into the house and the resident cat(s) will use spray or claw marks to delineate a boundary at the edge of a more restricted core territory which happens to be within the home. For example, cats may end up inhabiting certain rooms of a house as core territory and then use spray marking or maddening in rooms that are overlooked or entered by non-resident cats. This situation often starts with urine marks primarily being deposited around windows, external doors, or around the cat flap.

If the relationship between cats within the home is dysfunctional, then there may be two or more factions coexisting within the home, with little tolerance for each other. Most domestic cat groups are of mixed sex, breed and age, and are not actively engaged in mutual kitten rearing. There is therefore no functional basis for the cats to coexist other than their own individual social preferences and affiliations. The continued function of the group is highly dependent on whether present resources are plentiful enough to maintain the whole group without competition. Within domestic cat groups sharing a home, it is possible to identify patterns of interaction by analysing greeting, affiliative and aggressive behaviour between cats (see example diagram). This can be used to identify factions or individuals that do not form part of a cohesive social group, so that resources can be redistributed and measures taken to improve social cohesion.

Identifying the social structure of the group may give insights into why the relationship between resident cats has broken down. For example, the loss of a social facilitator cat may cause aggression to begin between factions because no other individual is maintaining the group odour. The same situation can occur when the owner goes away on holiday or when a social facilitator becomes ill or infirm. The role of a particular individual may change according to its health status. A pair or faction may break up if one cat suffers from pain, hyperaesthesia or some other condition that changes its acceptance of grooming or affiliative behaviour. It may change to become a satellite individual, with little participation in the group. A polyphagic hyperthyroid or diabetic cat may consume more food or despotically control access to it, leaving the rest of the group resource deficient. Investigating and treating marking problems that relate to social difficulties between cats can be demanding.


Underlying medical conditions should be investigated and treated. Regardless of the cause for the marking behaviour, it is useful to increase available resources so that cats have easy access to them and perceive their core territory to provide a surfeit of the things that they need. F3 diffusers (Feliway) help to create a sense of core territory and can considerably reduce tension in cat groups. In one UK-based study spray marking was reduced by 91% after 35 days of application of a pheromone diffuser[1]

Soiled areas should be protected to prevent soiling from becoming ingrained and harder to remove.

Marking Caused by an External Threat

In the case of spraying caused by an external threat from cats, the perceived threat must be reduced and the boundary of the core territory strengthened. Changes might include installing an electronic coded cat flap so that outside cats cannot gain access to the home and the use of glass coating film or sprays can be used to make windows opaque enough that other cats cannot see into the home or be seen from inside. This does not affect indoor light levels and the material can be applied to a limited area of window to obscure a selected part of the view. This prevents non-resident cats from using visual threats (posture, eye contact) to intimidate resident cats in their own home. It also prevents the resident cats from using internal vantage points to watch cats outside, and encourages them to go outside instead. This includes preventing reactionary spraying on areas around the window, which are intended to be a deterrent to the outside cat. The coating may be removed after marking has stopped for a period of 8 or more weeks, sometimes in strips in order to make the transition back to normal transparency more gradual.

The intensity of core territory and facial marks can be enhanced using F3 diffusers and spray (Feliway). These should be positioned in each of the rooms in which the cats spend a lot of time, and used at a rate of 1 per 50-70 m2. F3 may have no effect if used at less than this rate.

Having made the core territory safer, the aim is to enable the cats to re-establish a pattern of territorial defence outside. The cats should be given vantage points within the garden that allow them to control their territory, but which face away from the house so that non-resident cats cannot use these perches to threaten the owner’s cats. Non-resident cats may have favourite places from which they use long-distance visual threats to intimidate the client’s cats. These should be removed or altered so that they are unusable. For example, placing anti-burglar "prickle strips" onto shed roofs to make them uncomfortable to sit on.

The cat also needs to have an opportunity to leave proper scent marks to maintain a territorial boundary. In some gardens there are no suitable objects to claw or spray mark. Softwood posts make good clawing places and they should be installed at the edge of the territory so that the resident cats are able to leave appropriate territorial scent marks. They can be made more attractive by raking them with a wire brush or rubbing them against an existing claw marked object to pick up a scent. Claw posts or pads near to the cat door inside the home enable the cat can leave a territorial scent mark without spraying. Resident cats should be provided with outdoor latrines around the edge of the garden, as these also help to strengthen territorial boundary and reduce the need for resident cats to cross other territories to find a latrine.

Marking Caused by an Internal Threat

If indoor marking has been caused by conflict between cats in the home then comprehensive environmental enrichments should be provided. The aim is to provide separate factions with their own resources so that they can effectively live independently within a shared domestic space. This ability to coexist without competition actually increases the likelihood that the cats will develop an affiliative relationship.

Urine marks are self-perpetuating because the marker needs to refresh them periodically to maintain their meaning. When cats spray indoors, this creates an environment that contains a mixture of facial and urine marking odours that disrupts the continuity of the core territory. For these reasons, it is very important to thoroughly remove urine odours. Scented products and those containing ammonia should not be used to clean up spray marks because they may intensify urine odours and leave an objectionable smell that encourages over-marking. Feliway diffusers and spray, which contain a synthetic analogue of the F3 fraction of feline facial marks may be used to supplement facial and flank odours. These scents may also be harvested from the cats and then spread around the house.

Group odour is crucial to maintaining a conflict-free multicat household, but once relationship breakdown occurs the cats are unable to maintain or re-establish this for themselves. In the same way as for treatment of inter-cat aggression in the household, it is possible to classically condition an association between the odour of a specific cat or cat-faction and the presentation of food or play. The scent is harvested from the facial and flank regions of the individual cats (or factions) onto separate cloths. The cloth from one individual or faction is then regularly presented to one of the other cats before giving food or play, until that cat shows a positive response to the odour. That cat’s cloth is presented in the same way to the group or individual represented by the cloth. Initially the presentation of the odour may cause some alarm. However, after repeated presentation, each cat should begin to rub against the cloth when it is presented, which indicates that the odour has been fully accepted. The body odour of the factions or individuals may then be merged, by exchanging odours between them [see diagram below]. In situations where there is overt aggression between cats it is best to isolate them for a period of 1 to 2 weeks and reintroduce them as if bringing in a new cat for the first time.

Sites that have been spray marked can be made less attractive for cats in a number of ways, but it has to be remembered that if the motivation to mark is strong, this will merely displace the activity elsewhere. Deterrent methods must only be used in combination with other environmental modifications that reduce the motivation to scent mark. Cats are generally reluctant to spray or midden close to feeding sites, so small bowls may be put close to spraying locations. This also increases the number of feeding places. Odour deterrents should be avoided, because these may actually draw attention to spray sites or produce odours that the cat will attempt to overmark. Sheets of aluminium foil or plastic can protect the floor around a spray site, whilst also deterring cats from going there. These methods are best used for isolated locations where it is imperative that the cat does not spray, such as around electrical equipment.

Claw marking often exists as a sub-problem in indoor spray marking cats. Claw marks have a similar territorial function to urine spraying and the rate of claw marking may increase along with indoor spray marking. Providing cats with good claw marking sites that fit with their need to defend territory can be an effective way to shift the pattern of marking from spraying to clawing. Claw marking posts or pads may be positioned close to windows, doorways and cat doors. They can be made more attractive by rubbing them against existing clawing sites and then raking them with a wire brush to simulate real claw marks. Undesirable claw marking can be deterred by daily application of F3 spray, combined with the provision of a nearby alternative scratching place.


A number of studies support the use of pheromonotherapy for the treatment of indoor marking in cats[2]. The product Feliway contains a synthetic analogue of the F3 fraction of the facial marking secretion of cats[1]. The presence of this chemical signal deters spray marking on a specific spot, and the general concentration of the chemical signal in an environment may reduce stress and interact conflict that underlie spray marking. Current evidence suggests that Feliway diffusers or sprays need to be used for a minimum of 4 weeks in order to produce a reduction in spray marking[2].

Psychoactive Drug Therapy

Medication can be very effective; a study by Landsberg & Wilson found that 20 out of 25 cats treated with clomipramine at a mean dose of 0.54mg/kg showed a reduction in spraying within 4 weeks[3]. In a meta-analysis of the effectiveness of treatments used for indoor spray marking both fluoxetine and clomipramine were found to reduce spraying by at least 90%[2].

Psychoactive drug therapy is often prescribed for cats with indoor marking problems. However, to be successful, the underlying reasons for the indoor marking must also be addressed. Medication does have a role in longstanding cases where the number of marked sites is large, or when marking has become habitual, or there is an emotional problem that may benefit from temporary drug support. Analysis of the general emotional state of the animal is important. SRI/SSRI drugs such as fluoxetine and clomipramine are beneficial for cats that are habitual indoor markers, or show a pattern of anxious, reactionary spraying. Selegiline benefits behaviourally-inhibited cats that will not explore their environment, or that display fearful reactions followed closely by reactionary spraying when they see certain cats lurking outside the home. These drugs will not help confident cats that show no signs of anxiety or fear and are merely using spray marks, albeit inappropriately, as part of a calmly considered strategy to control territory in the house. Hormonal preparations have no role in the treatment of indoor marking.

The Decision to Use Psychoactive Drugs for Indoor Marking

Psychoactive drugs may be of value when:

  • Individual cats are showing signs of chronic anxiety (SRI/SSRI) or inhibition of normal behaviour (Selegiline).
  • The problem is of 6+ months duration.
  • Multiple sites are being sprayed.
  • Response to environmental change has been incomplete.
  • Spraying is a reaction to specific fear (Selegiline).
  • A rapid resolution is demanded and the client can be relied upon to complete environmental modification.

Problems with using psychoactive drugs include:

  • Disinhibition of aggression: SRI/SSRI/benzodiazepine drugs.
  • Poor owner compliance: Owners may not give medication consistently, or they may rely on its effects and fail to introduce the prescribed environmental modifications.
  • Relapse: This is likely if drugs are withdrawn before environmental and social factors have been remedied. Relapse is seen in 80% of cats treated for indoor marking with benzodiazepine drugs, so this class of drug is no longer recommended.
  • Potential adverse effects of drugs: Fatal hepatic disease after oral benzodiazepine administration, cardiovascular effects of SSRI/SRI drugs.
  • Interactions with concurrent medication or disease: Drugs that affect the function of cytochrome P450 can interfere with the metabolism of SRI/SSRI drugs (e.g. Cimetidine). SRI drugs should be used with care in cats with thyroid disturbance, or with bladder disease (risk of outflow obstruction).

Treatment summary: Indoor Marking

General Changes
  • Provide additional resources around the home, including extra resting, feeding, drinking and latrine sites. These should be located so that each faction or individual cat has easy access to its own set of resources close to a location where it spends time.
  • Soiled sites should be cleaned properly.
  • The cats should not be punished or threatened and chased when spraying, as this may increase stress or encourage the development of spraying to gain attention.
  • Strategically install F3 diffusers (Feliway).
External Threat
  • Install one or more coded electronic cat flaps to prevent entry by non-resident cats. Transparent cat doors should be coated with a solid coloured paint or film so that they are completely opaque, otherwise non-resident cats may threaten residents through them.
  • Use a film or spray coating to prevent outside cats from seeing into the home through windows close to where the resident cats have sprayed, or which overlook resources. These sprays and coatings are commonly sold as obscure glass coatings for bathroom windows.
  • Install scratching posts, vantage points and latrines in the garden so that territorial control is shifted from inside to outside.
  • If a stray entire male cat has moved into the area it should be trapped, neutered and homed away from the area.
Internal Conflict
  • Follow general advice on resource distribution, giving each faction its own feeding stations and other resources. Consider providing an additional cat-door if one cat is controlling access to it.
  • Introduce simulated foraging (activity feeding).
  • Use scent reintroduction and scent swapping to re-establish a group odour.
  • Consider isolating and reintroducing cats in accordance with guidelines on dealing with inter-cat aggression.
  • If cats have spent time away from the group, reintroduce them appropriately.
Unfamiliar Odours Coming in from Outside the Home
  • Regularly clean doorways, paths and walls where non-resident cats are spray marking (scrub with a solution of biological washing powder and hose clean).
  • Fit draft excluders around doors and frames to prevent odours from coming in, and install a weatherboard to the bottom of external doors so that urine marks do not run down the door and into the house.
  • Take off outdoor shoes and put them on a high shelf when entering the house.
  • Apply a squirt of F3 (Feliway) to bags when they are brought into the house.
  • Allow new furniture to air for several hours before allowing the cats access to it. This allows plastic and other odours, that may trigger spraying, to disperse. Apply F3 spray (Feliway) to the furniture regularly until cats are voluntarily face and flank marking it.

Withdrawing Treatment

Environmental modifications that are made outside should be permanently maintained, but coatings on windows, food bowls that have been used as spraying deterrents and other minor environmental modifications should be gradually removed after a period of 6-8 weeks without spraying. Psychoactive drugs or F3 diffuser therapy should be gradually withdrawn after 6-8 weeks without spraying or after the temporary environmental modifications have been removed. Although not mentioned in the data sheets for psychoactive medications, these drugs should be withdrawn gradually in order to avoid withdrawal effects. In humans, sudden withdrawal of short half-life serotonergic drugs can produce "discontinuation syndrome". Typically the withdrawal period is 1 week per month of treatment, with the dose being reduced in three separate steps (75%, 50% and finally 25% of the original dose). Feliway diffusers can be allowed to run out completely, one at a time, after drugs and temporary environmental modifications have been removed. If inter-cat hostility exists in the household then Feliway diffusers should be continued until the cats have fully re-established their previous allogrooming and allorubbing affiliative behaviour.


The prognosis for cats with indoor spray marking appears to be enhanced by the use of drug (fluoxetine, clomipramine) and synthetic pheromone treatments (F3 fraction of facial mark, Feliway®). In a meta-analysis of treatment effect, fluoxetine appeared to be the most effective medication, but sample sizes in both of the included studies was small. Both fluoxetine and clomipramine produced a large and significant increase in the proportion of cats showing a cessation or 90% reduction in spray marking (the primary outcome measure for the meta-analysis). Studies suggest that a period of 8-16 weeks is required to establish efficacy of either of these drugs. In the same meta-analysis, treatment periods of 4 weeks with Feliway produced no significant increase in the proportion of cats showing a cessation or 90% reduction in spray marking (primary outcome measure). However, a large effect was detected when comparing the number of cats that reduced spraying compared with baseline (secondary outcome measure)[2]. The authors indicate that synthetic pheromones do reduce the overall incidence of spraying only after 4 weeks. This suggests that a combination of pheromone and pharmaceutical interventions, with environmental modifications, is most likely to produce a rapid response and good outcome.

However, cats with a history of indoor marking are likely to relapse at some point in the future, because this behaviour is normal and situations outside the owner’s control may create the conditions for a new bout of marking. Typical times when marking may re-emerge are after major home redecoration or reorganisation, after a house move, or the introduction of a new stressor (new baby, new pet). Spring and summer are times when cats seek to re-establish territorial boundaries, and are therefore a time when there is an increased risk of conflict and stress between cats. It is possible to minimise the risk of recidivism by continuing to provide an excess of resources and maintaining a suitable core and garden territory for the cats. If a new bout of marking is anticipated, then the environmental changes and Feliway diffusers may be temporarily reinstated.


  • New cats should be introduced carefully and preceded by an appropriate increase in resources for the group.
  • When redecorating, building or making changes to house layout, install an F3 diffuser (Feliway) to maintain core territory odour signals. Allow paint to dry and the room to air thoroughly before allowing the cat(s) back into it. Harvest facial and flank odours from the cat(s) and apply these to doorways, and furnishings in the newly decorated area. If the cat is particularly sensitive to change it may be better to arrange a cattery stay during major projects of redecoration or renovation, especially if they involve core territory areas for the particular cat.
  • Provide adequate resources for the group.
  • When cats are temporarily removed from the group (such as when going to the vet clinic) they should be reintroduced carefully after trying to re-label them with the group odour. They should be allowed several hours of isolation to groom and clean themselves, and then be allowed access to use beds and resting places that carry odours that will help to mark the returning cat with the group odour.

Indoor Marking - Cat Learning Resources
Selection of relevant videos
Spray Marking Problems in the Cat video


  1. 1.0 1.1 Mills, D.S., Mills, C.B., 2001. Evaluation of a novel method of delivering a synthetic analogue of feline facial pheromone to control urine spraying by cats. The Veterinary Record 149, 197–199.
  2. 2.0 2.1 2.2 2.3 Mills, D.S., Redgate, S.E., Landsberg, G.M. (2011) A Meta-Analysis of Studies of Treatments for Feline Urine Spraying. PlosOne. 6(4), 1-10.
  3. Landsberg, G.M., Wilson, A.L. (2005) Effects of clomipramine on cats presented for urine marking. J Am Anim Hosp Assoc. 41(1), 3-11.

The creation of this content was made possible by Ceva Santé Animale as part of the feline behaviour project. Ceva logo.jpg

WikiVet® Introduction - Help WikiVet - Report a Problem