Common feline problem behaviours: Unacceptable indoor elimination

Abstract

Practical relevance:

One of the reasons why cats enjoy such a high level of popularity as domestic pets is the fact that they are clean. When there is a breakdown in this fastidious behaviour and elimination occurs outside of the litter box or tray, the strain on the cat–owner bond and on human relationships within the household can be considerable.

Evidence base:

Indoor elimination behaviour is one of the most common reasons for cat owners to seek professional advice and there is a wide range of articles, book chapters and research papers that reference it. In many cases the topic of urination and defecation in unacceptable indoor locations is considered in combination with the deposition of urine or faeces as a marker, but this review focuses purely on problematic elimination. An accompanying article in this special issue discusses urine spraying.

Clinical challenges:

Indoor elimination problems necessitate a clinical approach combining knowledge from the fields of physical and emotional health and an understanding of normal feline behaviour. They also require comprehensive history-taking skills as well as effective communication skills and a degree of empathy for owners who are often finding their pet’s behaviour very distressing.

Global importance:

Early diagnosis of physical health disorders that are associated with indoor elimination is extremely important in terms of safeguarding feline welfare. As we become more aware of the interplay between physical and emotional health, the significance of identifying suboptimal social and physical environments in terms of optimising the welfare of domestic cats is also being recognised. The potential for indoor elimination problems to cause considerable human distress highlights the importance of the concepts of One Health and One Welfare.

Introduction

House-soiling is a global term that encompasses a range of potential causes leading to the deposition of urine and/or faeces in places that are unacceptable from a human perspective. When owners discover such deposits within the home they are often very distressed and tensions between family members can be significant. In some cases the relationship between the cat and human caregivers can break down entirely and it is recognised that feline house-soiling is a significant factor in the relinquishment of cats to animal shelters. ¹

In order to be able to offer practical help and achieve resolution of the problematic behaviour, the most important part of investigating these cases is to establish the underlying motivation for the individual cat. The four important differential diagnoses to consider are: ²

• Feline idiopathic cystitis (FIC);

• A medical aetiology (other than FIC);

• Marking (using urine and/or faeces as a communication tool) – most commonly urine spraying;

• Elimination (physiological deposition of urine and/or faeces) – related to primary environmental and social factors.

Elimination related to primary environmental or social factors

The ability of cats to reliably use litter facilities provided within the home makes it easy for owners to go out to work and spend time on their own leisure pursuits without worrying about whether the cat is desperate to toilet. The fact that the majority of kittens are already reliable in their use of the litter box when they arrive in their new home increases the perception that kittens are easier than puppies and adds to their popularity. Dealing with cases of unacceptable elimination involves understanding normal feline toileting and identifying why this particular cat is finding its preferred location or substrate more attractive than the litter facilities provided by the owner or the available locations in the outdoor environment. Consideration of the influence of the social and physical environment, and the associated emotional motivations, in these cases is as equally within the remit of the veterinary profession as identification of potential contributing physical diseases.

Normal feline elimination

When cats deposit urine and faeces through elimination they look for quiet and secluded locations where they will not be disturbed. The chosen substrate is usually conducive to creating an indentation in which to eliminate and then raking to cover the deposit after the elimination has occurred (Figure 1).

Figure 1.

For normal feline elimination cats look for a quiet location, and a substrate that is conducive to creating an indentation in which to eliminate and allows raking to cover the deposit. Image ©Shutterstock/VeronArt16

In house-soiling cases related to elimination (as opposed to marking), the location of the deposits and the location of the litter boxes needs to be evaluated; the latter in terms of their ability to offer privacy and seclusion. The litter material has the potential to create aversion to the use of the litter box, and features of the litter box itself, such as its size and whether it is hooded, have also been proposed as potential contributing factors.^2,3 Litter box management in terms of hygiene and frequency of cleaning is important too and should be investigated. ⁴

Involvement of physical disease

FIC should always be considered as a causal factor, ² since pain associated with passing urine can lead to negative associations with the litter box location and subsequent onset of unacceptable indoor elimination. Similarly, medical conditions such as chronic pain and diseases causing polydipsia and polyuria, such as diabetes or renal failure, may coexist with indoor elimination and be involved in the aetiology. Other medical considerations include age-related conditions such as hyper-thyroidism, cognitive dysfunction and neurological and sensory impairment.^3,5

Full clinical examination and additional tests, where necessary, is the first step in the investigation of these cases. ⁶ However, studies have shown that there is a high prevalence of medical issues in the domestic feline population, and finding a physical health-related problem does not necessarily indicate that it is causal in relation to the reported house-soiling. ⁵ The potential for involvement of environmental factors, both social and physical, will also need to be investigated.

Marking or elimination?

Accurate and comprehensive history taking is essential in order to determine the underlying motivations and distinguish between marking and elimination. Importantly, a recent study has highlighted the risk of misdiagnosis, in cases involving urine deposits, if only a single sign is used as the basis for diagnosis. ⁵ The sensitivity and specificity of some of the commonly accepted features for differentiating between unacceptable indoor elimination and marking in cases of periuria – namely posture to urinate, attempt to cover the soiled area and volume of urine deposited – were recently calculated by the investigators, a research group at Lincoln University, UK. ⁵ Traditionally, it has been suggested that a standing posture is indicative of a marking issue, while a squatting posture indicates elimination. Attempts to cover soiled areas and deposition of large quantities of urine have been used as diagnostic features in cases of unacceptable elimination, while the absence of covering behaviour and deposition of small or medium deposits have been used to identify a marking motivation. While these features were all significantly associated with the expected related form of periuria in this study, they did not show high levels of specificity and sensitivity. ⁵

The consequence of this is that using any one of these features as a single criterion when differentiating between potential motivations for deposits of urine in unacceptable locations in the home is unreliable. The study found that if the volume of the deposits is used as a single criterion, with large volumes taken to determine that a cat is engaged in elimination-related rather than marking-related behaviour, then 36% of cases with elimination problems would be missed. Conversely, if a small to medium volume of urine is used as confirmation that a cat is marking, 26% of indoor elimination cases would be misdiagnosed. ⁵

The criterion of deposition of urine on vertical surfaces being associated with marking behaviour was shown in this same study to be less likely than volume of deposits to lead to misdiagnosis of elimination-related house-soiling. However, deposition of urine on horizontal surfaces being used as a criterion for elimination-related behaviour was less reliable, and a quarter of cats in this category were found to have a marking issue. The commonly used differentiating criteria of posture during urine deposition and the presence or absence of attempts to cover the urine were seen to be more reliable than position of the deposits, but using either of these two criteria alone for diagnosis was also shown to be flawed.

The results of the study highlight the importance of undertaking a comprehensive assessment of the case, focused on excluding the differentials, rather than relying on solitary indicators or simply gathering positive evidence in support of one particular diagnosis. ⁵

Risk factors and triggers

Living in a multi-cat household has been shown to be a significant risk factor for elimination-related house-soiling, although increased feline population density within the home appears to have a greater influence on the incidence of marking. ⁵ The availability of access to the outdoors has been associated with a lower incidence of elimination behaviour in undesirable indoor locations and it has been suggested that this may be related to less frequent litter box use, and a resulting increase in cleanliness, when cats have the option to eliminate outside (Figure 2). ⁷

Figure 2.

Living in a multi-cat household and having no access to the outdoors have been associated with an increased risk of unacceptable elimination, but this correlation warrants more investigation.

Image ©Shutterstock/bellena

Unacceptable indoor elimination refers to the deposition of urine and/or faeces but the majority of reported clinical cases involve urination. The finding that the risk of faecal elimination in unacceptable indoor sites is five times higher in cases where elimination-related periuria is also reported, compared with cases of indoor marking or controls, ⁵ is consistent with the fact that commonly reported triggers for unacceptable urination in the home, such as suboptimal litter facilities, are relevant to all elimination behaviours.

Investigation of unacceptable indoor elimination

Investigation of house-soiling cases, as with any behavioural medicine case, can be time consuming and challenging, and requires a comprehensive behavioural history (Figure 3). A logical approach to history taking needs to be combined with observation of the environment of the cat, either directly through house visits or indirectly via videos and house plans. This will not be possible within a standard general practice veterinary consultation and specific time will need to be allocated for investigation of these cases. Tools, including questionnaires, timelines, house plans and affiliative behaviour maps, can help to increase the efficiency of information collection.

Figure 3.

History taking enables potential triggers for indoor elimination, such as the arrival of a new cat in the neighbourhood, to be identified. These can then be marked onto a timeline (see page 203) and their significance investigated further. Image ©Shutterstock/Svetlana Mihailova

Information-gathering tools

Questionnaires

One way of encouraging a logical approach and ensuring that all potentially relevant information is collected during history taking is with the use of questionnaires. Numerous examples exist in the literature;^8,9 the home life and environment questionnaire in the article in Part 1 on behavioral awareness in the feline consultation is one such example. As every case is unique it follows that there is no perfect questionnaire; most behaviour specialists develop their own and then refine it over months and years of experience of dealing with individual cases. The aim is to collect information about a range of factors that may influence the elimination behaviour of the cat. These will include: the physical environment, both inside and outside the home; the social environment, in terms of feline relationships and interactions with humans and other species; and the husbandry and management of the cat(s). Details about the deposits of urine and/or faeces found within the home will also be needed. ¹⁰

Timelines

A timeline (see box above) can be a particularly useful component of a comprehensive behavioural history, ensuring a chronological record is obtained. This is relevant in cases of undesirable indoor elimination and the clinician needs to establish, where possible, the chronology of the deposits if multiple locations are being used. In all cases the triggers identified by the owner for the indoor elimination need to be investigated, such as the arrival of a new cat in the household or the neighbourhood (Figure 3). It is also important to gather information about any other emotional triggers that may not have been recognised as problematic by the owner. Noting the occurrence of potential physical and social triggers onto the timeline, together with issues related to physical health, will help to identify temporal relationships between them and the problematic elimination behaviour.

Clients may not necessarily be aware of the significance of events and, in order to ensure that important information is not missed, the clinician will need to ask appropriate questions. These would include:

• Have you recently travelled and left the cat home alone?

• Have new family members (human or pet) been added to the home in the past year?

• Have there been any structural changes in your home, such as a new kitchen or major redecoration?

• Have there been any significant changes in your neighbourhood?

House plans

House plans (see box below) can be used to provide information about the indoor physical environment and the location of feline resources within it. They can additionally be used to illustrate the house-soiling sites, and it is helpful for these to be numbered in chronological order of deposition or discovery where possible. Information about the frequency of deposition at each site can also be included. ¹⁰ In multistorey homes, plans of each floor will be needed unless the cat(s) do not have access to any areas.

Litter box considerations

In addition to marking the locations of litter boxes onto a house plan it will be important to gather information about the suitability of the facilities provided. Litter boxes should be located well away from other resources such as food and water bowls and resting places. One exception to this may be the need for litter facilities to be closer to resting locations for elderly cats or those with pain-related medical issues. Information about the style of litter box, litter material used and the cleaning regimen is all going to be important in determining whether the facilities can be considered optimal from a feline perspective.

In multi-cat households it has been suggested in one study that the presence, in the litter box, of elimination deposits from incompatible cats may create an aversive scent signal and lead to avoidance of that location. ⁷ It has been shown that cats prefer a clean litter box to a dirty one, but the same study concluded that the identity of the previous user had no impact on preferences. ⁷ While the presence of odour from urine and/or faeces did not impact litter box preferences in that study, the presence of odourless fake urine and/or faeces did. These results suggest that chemical communication may be less important in litter box preferences; and highlight regular removal of physical/visual deposits as being a key factor in promoting litter box usage.

External physical environment

Restriction to a totally indoor environment is sometimes assumed to be a factor when cats are reported to be eliminating in undesirable locations in the home, but the onset of indoor elimination due to difficulty accessing previously utilised outdoor latrines is also reported anecdotally. Information about the external physical environment will be relevant in these cases, especially in terms of the feline population density in the neighbourhood and any alterations to the local environment that may have reduced access to desirable elimination locations, such as house building on previous open spaces or paving of gardens. For those cats that are restricted to indoor life, the potential relevance of the external environment should not be overlooked. For example, visual intrusion from other cats through windows (Figure 3), patio doors and transparent cat flaps can lead to a perception of threat to the safety of indoor latrines.

Feline social groups within the household

While cats may coexist under the same roof, this does not necessarily mean that they belong to the same social grouping. It is important to remember that cats do not have an inherent tolerance of feline strangers. Ideally, cats will live with genetically related individuals, thus sibling groupings may stand the best chance of success. Cats can also cohabit successfully with non-related cats if they are introduced early enough and in the right way (see accompanying article on aggression in multicat households). For a multi-cat household it is, therefore, important to determine not only how many cats there are but how many social groupings exist within the household.

Owners should be asked to spend time observing their cats and looking for affiliative behaviour patterns such as allogrooming (reciprocal social grooming by cats) and allorubbing (reciprocal social rubbing between cats) in order to establish how many social groups are living within the home. Observation also helps to highlight some of the more passive manifestations of social tension that are often overlooked. Owners are more likely to conclude that there is social tension if there is fighting and hostile vocalisation, yet more passive behaviours, such as staring and avoidance, are also important signs of feline hostility (see article in Part 1 on understanding feline emotions). It should be suggested that owners observe their cats over a 7 day period and record interactions such as rubbing and grooming on an affiliative behaviour diagram (see box below). Those cats that do not engage in these affiliative behaviours will find it stressful to be expected to share important resources such as resting places and entry/exit points.

The relevance of social groups in relation to problems of unacceptable indoor elimination is their impact on the availability of resources, including latrine facilities, in terms not only of the number of resources but also their location. Sharing of facilities between social groups is considered to be a potential stressor leading to increased risk of elimination-related house-soiling. Another influence of feline compatibility in this context relates to the increased risk of social tension in the location of the latrines (Figure 4). Anything that increases negative emotions of fear–anxiety or frustration has the potential to increase avoidance behaviour in relation to the provided facilities and promote seeking of alternative more secure locations for toileting.

Figure 4.

(a,b) Social tension in the vicinity of the litter facilities is likely to increase the risk of unacceptable indoor elimination. Image (a) courtesy of Nadine Gourkow; image (b) courtesy of Sarah Ellis

Interspecific social interactions

If cats are living in multi-species pet households the potential for latrine facilities to be perceived as not safe and secure may be understandable. For example, the presence of a dog drooling in expectation of a warm snack while the cat is attempting to defecate in a litter box might well be expected to lead to avoidance of the litter box in the future! Relationships with humans in the household should also be investigated, as social tension between cats and their caregivers may lead to lowered feline self-confidence and consequent seeking out of more protected toileting locations. Examples might include households in which inappropriate gadgets, such as water pistols or rattle cans, have been used to stop the cat behaving in certain ways or where humans have been over-enthusiastic in their social interactions, such as picking the cat up to show it affection, and inadvertently caused a feline perception of confrontation. In addition to considering individual relationships, it should also be identified when latrine facilities are located in areas with the potential for high levels of human activity (eg, in a hallway), as this could lead to the cat feeling vulnerable while using them.

Treatment of elimination-related house-soiling problems

In cases of unacceptable indoor elimination the ultimate aim is to re-establish appropriate associations with locations and substrates. In order to achieve this it is important to optimise the cat’s environment, not just in terms of latrine facilities (which involves ensuring access to optimal latrine sites outdoors where applicable, as well as optimising the litter box facilities in the home), but by providing for all of the recognised feline environmental needs (see article in Part 2 on environmental and behavioural modification).

The approach to treatment incorporates three key aspects:

• Dealing with potential disease (see earlier)

• Addressing emotional motivations

• Optimising litter facilities

Addressing emotional issues

To address the potential for the negative emotional motivations of fear–anxiety and frustration to be playing a role in cases of unacceptable indoor elimination it is important to ensure that the environment provides for the ‘five pillars’ of feline environmental needs. These are described in the 2013 guidelines produced by the AAFP and ISFM, ¹¹ and also discussed in the article in Part 2 on environmental and behavioural modification.

Paying attention to provision of a safe place, an environment that respects the feline sense of smell, positive, consistent and predictable human social interaction, and outlets for play and predatory behaviour, is equally as important as ensuring that there are multiple and separate environmental resources within the home. In other words, as well as requiring optimal facilities in order to encourage acceptable elimination behaviour from cats housed in a domestic environment, it is important to consider the requirement for optimised emotional health.

Optimising litter facilities

It can be helpful to provide some optimum litter facilities in addition to any litter boxes that are already available in the home and use a diary of elimination habits to establish each cat’s preference. Although there are some guidelines for optimising latrine facilities (see box above), every cat is an individual and the best and most practical way to ascertain the optimal facilities for each cat is to offer choice and remove any unused trays, if appropriate.

Figure 5.

(a) Poor litter facilities: litter boxes should be positioned away from food and water, and polythene liners should not be used. (b) This tray is in a secluded location and provides this cat with adequate space to defecate comfortably. A bigger tray may be required as the cat grows. Image (a) sourced by Vicky Halls; image (b) ©iStock/npdesignde

Clean appropriately

In addition to providing suitable latrine locations it is important to reduce the attraction to undesirable locations. Removing the scent from deposits in unacceptable locations is therefore a crucial part of the treatment plan – it is essential that no residue is left from the cat’s perspective. Avoid any form of cleaning product that merely masks the scent to the satisfaction of the humans in the household (see box on the left).

It is also important to remember that scents may have different effects on cats than they do on humans. While ammonia and chlorine are often associated with a sensation of cleanliness for humans they can be perceived as indicators of urine deposition for cats. Similarly citrus fragrance is very popular with people but is aversive from a feline perspective. Selection of cleaning materials to be used generally within the house is therefore something that cat owners need to consider carefully.

Owner perception

It has been suggested that factors such as the owner’s perception of the cat’s bond to them may play a role in clinical cases of house-soiling. In a recent study cats with a perceived ‘affectionate bond’ were more common among latrine-related elimination cases compared with cases of indoor marking or control cats. ⁵ This requires more investigation and the potential for owner perception to influence tolerance of house-soiling problems is also worth consideration.

Key Points

• Indoor elimination involves normal toileting behaviour in unacceptable locations.

• Understanding of normal toileting behaviour is key to providing optimised latrine facilities within the home.

• It is important to identify why the cat is not using acceptable locations, as well as why it is selecting unacceptable ones.

• Consideration of potential physical health issues is a priority.

• Management involves consideration of feline environmental needs and the provision of an optimised environment.