Feline Housesoiling Problems
Part I: Inappropriate Urination and Defecation
Article (c) and reproduced by kind permission of Dr.
Barbara Sherman Simpson, MS, PhD, DVM
Animal Behavior Service of the Veterinary Teaching Hospital, North Carolina
State University College of Veterinary Medicine,
Feline housesoiling problems are the most common behaviour complaints made by
cat owners to primary veterinarians. In addition, elimination problems involve
33% to 59% of referred feline behaviour problems.1-4 If not resolved,
housesoiling problems can lead to rehoming, relegation outside the home,
abandonment, or euthanasia of the offending cat (Figure 1).5 These behaviour
problems impact feline-human relationships, including the owner-pet bond, and
can lead to the loss of the cat as a veterinary patient. The welfare of the pet
as well as economic incentives should prompt veterinarians to develop expertise
in the diagnosis and treatment of such behaviour problems.
Feline housesoiling problems can be divided into those relating to elimination
outside the litterbox (discussed in Part I), including inappropriate urination.
and defecation, and those related to marking behaviour, which can involve either
urine or faeces (discussed in Part II). In all cases, it is imperative that
medical differential diagnoses be eliminated before proceeding to behaviour
Even when a medical diagnosis is made, behaviour therapy may be needed
concomitant with medical treatment because behaviour problems can arise as a
result of negative conditioning. For example, a cat experiencing urethritis may
associate pain with the litterbox and seek alternate sites for urination. A
behaviour .modification program may be required to re-establish satisfactory
Urine housesoiling problems include inappropriate urination and urine marking.
Although both involve urine, the functions of each of these activities differ.
Inappropriate urination, discussed here, involves elimination of urine outside
the litterbox at locations. unacceptable to the owner. Urine marking (discussed
in Part II) involves the use of urine in the act of olfactory communication,
which may occur independent of the act of urination. Fecal housesoiling problems
include inappropriate defecation, which may accompany inappropriate urination,
and faecal marking, called middening (discussed in Part II).
Inappropriate urination occurs on horizontal surfaces outside of the litterbox
and may be exhibited by individuals of any age, breed, or j sex. In cases of
simple inappropriate urination, cats squat to urinate outside the litterbox.
Often the location is in the vicinity of the litterbox or other locations in the
house. Remote, private sites, such as behind a couch, may be favoured. There may
be a specific substrate preference,6-7 such as topsoil surrounding houseplants,
shag carpet, or small area rugs. A spontaneous preference for a novel or nonabsorbent substrate, such as a porcelain sink, may be associated with a lower
urinary tract problem. Cats that urinate on the owner's bed or on clothing of
specific individuals are exhibiting marking behaviour.2,8 This problem is
When medical causes have been eliminated, the behaviour history should include
information on environmental factors that may be contributing to the problem.
One common behavioural cause of inappropriate urination is dissatisfaction with
some quality of litterbox, including insufficient cleaning.
Another important environmental factor is the relationship with other cats in
the household: For example, another resident cat may provide olfactory cues
litterbox that deter the problem cat from the site or playfully pounce on the
problem cat as it exits a covered litterbox, forcing it to seek "private"
elimination site where. Evaluating features of the litterbox and social
environment requires a systematic process of "asking the cat" what it prefers.
This approach involves providing boxes with different litter types in different
location counting the number of eliminations per box per day.
In general, inappropriate urination can be effective treated by environmental
control. Cats with a h of intermittent hematuria and waxing and waning may
benefit from presumptive treatment for inter cystitis. Such cats may benefit
from the use of the cyclic antidepressant amitripryline (discussed in II), which
has been used for the treatment of inter cystitis in women; it has also been
shown to be effective for management of feline interstitial cystitis.9
There are numerous behavioural diagnoses for inappropriate defecation, including
dissatisfaction with such qualities of the litterbox as location, type, or
cleanliness. In these cases, inappropriate
defecation may accompany inappropriate urination.8 Observation of the cat may be
suggestive. Although there are individual differences, the normal behaviour
sequence for defecation involves choosing a site with loose substrate (such as a
litterbox), digging a shallow depression, defecating at the site, and then
covering the faeces with raking movements. The latter behaviour is stimulated by
the odour of faeces and may be attempted when defecation occurs on the floor.
Cats that deviate from the normal behaviour sequence and straddle the litterbox,
tiptoe into it, shake their paws after touching the litter, or exit the box
immediately without covering the faeces are indicating an aversion to the
litter.6 Some cats will not defecate in litterboxes that are cleaned
infrequently. Other fastidious cats prefer to urinate in one litterbox and
defecate in an adjacent clean box.
Social interference is a common cause of inappropriate defecation. Another cat
may interfere with the completion of the problem cat's preferred defecation
routine. A child or coprophagic dog in the household may follow the cat to the
litterbox and disturb litterbox use. Surreptitious observation of the cat near
the litterbox may provide important information about features that influence
the cat's decision not to use it.
Elimination behaviour problems may be secondary to medical disorders. Thus a
medical evaluation is indicated for all cases of feline housesoiling.
Urine Elimination Problems
All cats with elimination disorders should be physically examined with
particular attention to palpation of the kidneys and urinary bladder. A
neurologic examination should be performed. The general history should explore
changes in eating, drinking, or activity patterns that may suggest a medical
cause affecting litterbox use. For example, a cat with polyuria due to diabetes
may find the litterbox unacceptably wet and may seek alternate locations for
elimination. The owner's presenting complaint may be that the cat is eliminating
outside the litterbox.
Appropriate screening tests should be performed. For urine-related problems, a
urinalysis (including specific gravity and sediment analysis) is the minimum
data base. The collection method should be by cystocentesis except in cases in
which cystitis is suspected. In such cases, a voided sample should be obtained
(if possible) to avoid further trauma to the bladder.11 Cystocentesis can result
in inadvertent hematuria, which can be differentiated from cystitis by the
absence of other signs of inflammation in the urine.12 Serial samples should be
collected from any cat in which the behaviour symptoms wax and wane.
A complete blood count with differential and serum biochemistry should be
performed as a screen on any cat with suspicious findings on physical
examination and prior to the use of extra label medications.4 These values will
be within normal limits if the inappropriate urination is strictly a behaviour
problem. If the behaviour problem is secondary to a medical problem, there may
be detectable abnormalities such as uremia, glycosemia, or hypercalcemia.
Further diagnostics, such as plain or contrast radiography or ultrasonography,
may be needed.
Inappropriate urination may be associated with a number of medical conditions,
particularly those associated with hematuria, polyuria/polydipsia, dysuria, or
pollakiuria. Older cats may suffer from arthritis or senility, which can limit
their ability to 'locate and climb into a litterbox.8 Neurologic abnormalities
may be implicated. Cats with refractory inappropriate urination should be tested
for the presence of hyperthyroidism, feline leukemia, and feline
immunodeficiency virus. The most common medical abnormalities associated with
feline inappropriate urination are listed in Table I below.
Medical Causes for Inappropriate Urination in Cats
Feline Infectious Peritonitis
Feline lower urinary tract
Feline interstitial cystitis
In a retrospective study comparing cats that exhibited inappropriate
urination with controls, problem cats were significantly more likely to have had
a history of lower urinary tract disorders (LUTDs).13 A survey at a large
teaching hospital found that 37% of cases referred to the behaviour service for
inappropriate urination had a history of feline LUTD.4 Feline LUTDs such as
metabolic disorders (uroliths), congenital abnormalities, neurogenic disorders,
and inflammatory and neoplastic processes should be investigated as potential
underlying causes of inappropriate urination.14
Nonobstructive idiopathic interstitial cystitis is an LUTD characterized by
inflammatory changes in the urinary bladder that may be accompanied by behaviour
changes in litterbox use.15 Because the disease waxes and wanes, it may be in
remission-and the urinalysis may be within normal limits-by the time the owner
seeks treatment for the secondary elimination problem. Interstitial cystitis
be considered in any cat with a history of hematuria and intermittent
Urine. marking is not usually associated with a medical condition; however,
behaviourists have anecdotally noted an increase in spraying concomitant with
inappropriate urination in some cases of LUTD,16 possibly due to agitation
associated with pain. Therefore medical evaluation should be standard for any
cat in which urine marking is associated with inappropriate (i.e., squat)
urination or with medical abnormalities (e.g., hematuria).
Fecal Elimination Problems
In cases of fecal housesoiling, a fecal examination should be performed to rule
out constipation, diarrhea, and internal parasites. Discomfort associated with
constipation in the litterbox may cause the cat to continue to seek alternate
sites not associated with pain. Enteritis or colitis may cause changes in
elimination habits. Urgency associated with loose stool may make the litterbox
too far away. Additional tests may be suggested by the history, physical
examination, or fecal tests, particularly if concurrent illness is suspected.
THE BEHAVIOUR HISTORY
At first inquiry, the client should be asked to keep a daily record of the
number of eliminations in each litterbox and the number of eliminations outside
the litterbox with the location noted (see Behaviour Diary below).
Sample of a behaviour diary.
Keeping such a diary reminds owners to clean the litterboxes daily,
monitor the home for "accidents," and quantify the frequency of the
problem. A simple form should be devised and given to owners to
Restricted during day
This information is used to quantify the frequency and location of the
problem at the start of treatment. The process encourages owners to clean each
litterbox daily and to monitor for new housesoiling incidents. After treatment
is initiated, owners should continue to keep detailed records of all
eliminations and their locations to evaluate the success of treatment.
As part of the behaviour history, the client should be asked to make a map of
the interior of the home, with sites of elimination and litterboxes marked so
that patterns can be visually identified (Figure 2). An electric probe to
detect wetness in the carpet pad, available from professional carpet cleaners,
may be needed to identify some urination sites.17
Solving an elimination behaviour problem often requires a search for information
in the history that suggests the underlying cause. This investigation is
facilitated by questions designed to provide "clues" that can lead to a specific
diagnosis and treatment (Table II).
Historical Questions Regarding Feline Housesoiling
Which animal is eliminating?
In single-cat households, there is no
ambiguity. It may be difficult in multiple-cat households to determine
with certainty which cat is responsible for inappropriate elimination.
Often, one cat has been identified by the owner but more than one
cat may be housesoiling. The
offending cat(s) may be identified by serially isolating each cat and
noting any change in the housesoiling pattern either visually or by the
use of fluorescein dye (see text).
What is being eliminated?
Determine whether urine, feces,
or both are being eliminated inappropriately. " Dissatisfaction with the
litterbox is strongly implicated when both are being deposited outside
If the elimination product is urine,
is it deposited on vertical or horizontal surfaces?
Vertical surfaces indicate urine
spraying. Horizontal surfaces usually indicate
Where in the home does
The use of a map with sites indicated
by the owner is helpful and may indicate a location preference or
influential social factors between cats (see Figure 2). An acute shift
from one substrate, such as litter, to an unusual substrate, such as a
porcelain sink, suggests a lower
urinary tract disorder.
How often does elimination occur?
Baseline frequency is necessary to
determine the extent of the problem and to monitor improvement.
When does the problem occur?
Daily or weekly temporal patterns of
inappropriate urination may suggest a specific environmental trigger.
How long has the problem been going
Acute onset in a cat that has
previously reliably used the litterbox suggests a medical problem or a
social cause. Duration of the problem affects prognosis. Chronic (months
to years) problems have a guarded prognosis for complete
Were there any environmental changes
associated with the onset
of the problem?
Changes in elimination habits can
occur with environmental change, such as a move to a new house.
What measures have been taken to
correct the problem?
Learning what techniques have already
been attempted can help guide the treatment plan.
Describe the litterbox
(location, size, box type, litter
type, how often cleaned).
Dissatisfaction with the litterbox is
a common cause of inappropriate elimination, particularly when both
urine and faeces are involved (see Table IV).
Several methods may be used to positively identity which cat (or cats) is
exhibiting inappropriate elimination in a multiple-cat household. Observing that
inappropriate elimination occurs shortly after one cat's access to the litterbox
is deterred by another cat is suggestive. Serial isolation restricts the spatial
utilization -of each cat sequentially and monitors housesoiling. Each cat is
isolated one at a time in a small room, and the "culprit" is identified by
process of elimination. However, such a protocol may sufficiently alter the
social milieu such that inappropriate elimination may not occur.
Fluorescein dye (0.3 ml subcutaneously, 0.5 ml orally, or six fluorescein strips
in gel capsules orally) may be administered to one cat; any urine that is found
outside the litterbox during the next 24 hours can be checked for fluorescence
using a Wood's light.18 If such urine does not fluoresce, Fluorescein should be
administered to each cat until the one responsible is found. A positive test
does not eliminate the possibility that more than one cat engages in urine
marking at other times. If fluorescein is administered but no urine is found
outside the box (a common finding when the frequency of the problem is low), the
test must be considered a diagnostic failure and should be repeated. Prior to
administration of fluorescein, the owner should evaluate a
"fluorescent-negative" urine mark with the Wood's light so that he or she can
distinguish it from one that is "fluorescent positive."
2 -Sample of a house plan submitted by the owner at the time of the initial
visit. Litterboxes are marked with circled numbers. Feeding (F), play (P), and
urination (U) sites are also noted. In this case, the problem was an older cat
whose inappropriate urination began when a young, playful cat was added to the
household. The older cat retreated to the master bedroom (presumably to avoid
the young cat) and began to urinate outside the litterbox there. Access was to a
covered litterbox in the master bathroom that was cleaned daily. When a second,
uncovered litterbox was added in the master bathroom, the cat began to use that,
and the elimination problem resolved. The covered litterbox was eventually
Appropriate treatment is initially determined by the presence, if any, of a
medical cause associated with the behaviour problem. Once any medical problems
have been appropriately addressed and a behaviour problem has been identified,
treatment may consist of one or more of the following: surgery, environmental
changes, behaviour modification, and pharmacotherapy. A medical evaluation is
always warranted prior to the use of medication. Treatment failure in a
multiple-cat household should prompt reassessment. More than one cat may be
housesoiling. Refractory cases or those in which the affected cat exhibits signs
of anxiety or arousal may benefit from antianxiety medication (discussed in Part
The goal of treatment of inappropriate urination is to enhance the appeal and
accessibility of the litterbox and to decrease the availability and appeal of
alternate sites.8 Details of the behaviour history may suggest a treatment plan
based on location or substrate preference. Cats that approach the litterbox and
eliminate in its vicinity are attracted to the loose substrate but are
dissatisfied with some other component of its quality or location." Methods of
improving litterbox use are presented in Table III below.
Recommendations for the Treatment of Inappropriate Urination and
Defecation in Cats 5-21
Scoop out the litterbox daily. Clean
it thoroughly once a week. Do not use scented cleaners or deodorants in
or near the litterbox.
Provide at least one litterbox per
cat and distribute them in more than one location. Be sure litterbox is
not located in a high-traffic or high-noise area. Move food bowls away
from the litterbox. If the litterbox is a covered type, provide an
additional large, uncovered litterbox without a fitted rim to determine
the cat's preference. Offer unscented, fine-grained, clumping-type
litter in the alternate box.19 Do not use a liner in the alternate box
because the odour of the plastic may be objectionable to some cats.8
Place an alternate litterbox
over sites of "accidents." Once the box is being used regularly, it can
be moved several inches per day to a site more acceptable to the owner.
Use deterrents at the site of inappropriate elimination. These can be an
unacceptable substrate such as aluminium foil
or plastic sheeting or odour deterrents such as citrus spray. Pine cones
may be placed at the base of houseplants to physically deter elimination
For longstanding problems and to
reduce the owner's distress regarding damage to carpets and floors, it
may be necessary to confine the offending cat in a small room (e.g., a
bedroom) remote from sites of housesoiling. A litterbox, food, and other
necessities should be provided.
When regular litterbox use has been achieved or when the cat is well
supervised, it can be let out of the room for increasing periods. Other
management techniques should also be practiced. Clean all inappropriate
sites with an enzymatic cleaner. Use a citrus deodorant spray or
double-sided tape to discourage the cat from visiting problem areas.
Use an electronic sound alarm or
electronic mat to deter a cat from an area where eliminations occur.
Behaviour modification techniques
include rewarding the cat with a favored treat for appropriate use of
To be humane and effective,
punishment must be of appropriate intensity and must follow within I
second of the offensive behaviour. Because the latter is rarely
possible, punishment is rarely effective. Corporal punishment or rubbing
the cat's nose in the elimination product is not appropriate or
effective. Punishment associated with sounds or movements by the owner
(as reaching for a spray bottle) will condition the cat to avoid the
owner. Counter conditioning may be used by feeding or playing with the
cat at inappropriate elimination sites.
Drugs are not usually indicated for
inappropriate urination. Instead, an environmental and behaviour
management plan should be implemented. Drugs should be considered for
refractory or complicated cases of inappropriate urination (see
Owners should maintain a record of
the number of urinations and defecations inside and outside (with
location) each litterbox each day so that progress can be documented.
The owner should monitor the house carefully for sites of inappropriate
elimination so that the frequency can be noted and the site can be cleaned
properly. Owners assume that the cat returns to the same site because of urine
odour cues. Although this has not been scientifically demonstrated, prompt
identification and cleaning of the site reduce the likelihood of unpleasant
urine odours in the home. After the site is identified, urine should be blotted
repeatedly with a dry paper towel to reduce the volume at the site. The area
should then be infiltrated with a commercially available enzymatic agent
designed for this purpose.17,20 Odour-masking agents may satisfy the owner and
deter the cat from the area.
Treatment of inappropriate defecation includes environmental alterations and
behaviour modification. Usually, pharmacotherapy is not required unless the
problem relates to generalized anxiety or there is a functional component of
marking (discussed in
Part II). The environment can be altered by adding a
second litterbox for defecation. Qualities of the litterbox may be improved by
cleaning it more frequently, increasing the depth of litter, or switching to an
unscented litter (Table IV 5,21). It may be necessary to prevent the cat from
having access to those areas where it defecated outside the litterbox in order
to reestablish appropriate litterbox use.
Litterbox Characteristics Affecting Inappropriate Urination
Frequency of cleaning
Many cats will reject a soiled box
and eliminate elsewhere. Owners who travel frequently, leaving the cat
and the litterbox untended for days at a time, may increase the cat's
dissatisfaction with the litterbox because of excessive soiling;
separation anxiety may also play a role.
Number of boxes
A minimum of one litterbox per cat
should be available to ensure cleanliness and reduce interference among
Remote sites (e.g., a basement) may
be inaccessible to an older or infirm cat. Bathrooms and laundry rooms
may be associated with excessive noise or odours that may be offensive
High traffic areas may be rejected
as unsuitable locations.
A covered litterbox may restrict
odours to an offensive level or may be too small for large cats to move
around in comfortably. The covered litterbox may allow other cats, pet
dogs, or young children to target the cat as it exits.
Preference tests indicate that most
cats prefer unscented, fine-grained (clumping) type litter over other
substrates.19 Scented litter is more frequently associated with
housesoiling problems than is unscented litter.13
Cats may be averse to odours that
humans consider attractive. The owner should avoid the use of
deodourizers in or near the litterbox.
Number of cats
In multiple-cat households, there is
a greater likelihood of heavy litterbox use, possibly resulting in an
excessively soiled litterbox. Another cat may interfere with the problem
cat as it approaches the litterbox, either through odour cues or
physically (e.g., aggressive acts or play solicitation in the vicinity
of the box).
For clients with good observation skills and patience, positive reinforcement
of appropriate litterbox use may be effective. Initially, the cat must be fed
twice a day on a regular schedule to determine the daily time of defecation. At
the determined time, the client should take the cat to the litterbox and wait
until it defecates. The cat should then be rewarded with a special food treat,
such as fresh salmon. This protocol should be repeated until the association
between the litterbox and defecation is confirmed.22
Feline housesoiling is a common behaviour complaint that causes frustration on
the part of the owner and can lead to euthanasia of the offending cat.
Successful treatment requires identification of the cat responsible (in
multiple-cat households) and of the cause of the problem. Housesoiling can be
divided into elimination problems, and marking behaviour. Elimination problems
may have medical or .behaviour causes. A physical examination and appropriate
laboratory tests are indicated to rule out medical causes or suggest appropriate
A careful behaviour history may reveal the factors) ,contributing to the
problem. Common elements include dissatisfaction with some quality of the
litterbox, including cleanliness, litter type, or location. Social interference
between cats or from other household members may contribute to litterbox
aversion. Behaviour treatment is often suggested by the behaviour history.
Resistant cases or those involving social factors may benefit from psychotropic
drugs (discussed in Part II).
About the Author
Dr. Sherman Simpson is Director of
The Animal Behaviour Service of the Veterinary Teaching Hospital, College of
Veterinary Medicine, North Carolina State University, . She is a Diplomate of
the American College of Veterinary Behaviorists and is Certified as an Applied
Animal Behaviorist by the Animal Behavior Society.
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