Advances in Companion Animal Behavior
0195---5616/91 $0.00
+
.20
Cat Elimination Behavior Problems
Peter L. Borchelt, PhD*
Cats have a generally well-deserved reputation of being naturally clean animals that readily learn to use a litter box. Data from a questionaire 7 filled out by more than 800 cat owners indicated that about one-half reported their cat(s) engaged in one or more problem behaviors and that about one quarter of these owners reported that their cat(s) eliminated out of the litter box at least some of the time. Thus, a conservative estimate is that at least 10% of pet cats at some time exhibit an elimination behavior problem. There are few data available regarding the correlation between breeds of cats and behavior problems, including elimination, .but some preliminary information has been presented. 6 General discussions of marking, urination, and defecation, the specific postures used for each behavior, and procedures for diagnosis and treatment have been presented elsewhere2-4 and are discussed here only briefly. This article provides some new information about cats' preferences for different types of litter materials. When a cat is presented to the veterinarian with elimination behavior problems, it is prudent to consider disease processes in the differential diagnosis. This article focuses only on behavior problems for which pathophysiologic causes have been ruled out.
BEHAVIORAL DESCRIPTION AND DEFINITION Posture Either a standing or a squatting posture can be used for voiding urine. Spraying or urine marking occurs in a standing posture with the hind legs straight and the tail upright and typically quivering while the cat steps alternately with the hind legs. Urine is sprayed horizontally onto vertical surfaces such as walls, table legs, bed ruffies, stereo speakers, and so forth. *Private Practitioner, Animal Behavior Consultants, Inc., Brooklyn, New York Veterinary Clinics of North America: Small Animal Practice-Val. 21, No. 2, March 1991
257
258
PETER
L.
BORCHELT
Generally, the amount of urine expressed is smaller than is voided during typical urination. When urinating or defecating, the hind legs are flexed and waste products are deposited onto horizontal surfaces such as litter boxes (ideally), floors, carpets, beds, couches, and so forth. Function and Context Urine marking generally is thought to have a communicative function because it occurs in the context of territorial, sexual, or agonistic behavior. Urine marking can occur when there are competitive interactions among and between cats within the household, between indoor and outdoor cats, and, rarely, between household cats and humans. The interaction involves some degree of obvious aggression or defensive displays by the cat. 5• 8 Urinating voids the bladder of urine and functions to remove waste products and relieve bladder muscle tension. It usually does not involve the same contexts and motivation as does marking. Defecating voids solid waste products and relieves bowel muscle tension, and usually does not serve as a marking or communicative behavior in domestic cats. Sequences of Behavior As with every other behavior system, elimination is composed of sequences of species-typical behaviors. The sequence of elimination behavior in domestic cats has been described2--4, 6 as approaching a specific .surface or location, digging with the forepaws to make a depression in the substrate, and eliminating, followed by sweeping and pawing motions of the forepaws to cover up the urine or feces. Individual cats vary in the occurrence and frequency of specific components of this sequence. Some owners report that a cat may not dig and cover in the litter box after urinating but simply walks into the box, squats, urinates, and then walks away. Some cats dig and scratch to varying degrees on the floor, wall, or side of the box. A cat may dig in the litter (or elsewhere) before eliminating and not afterward, afterward and not before, both before and after, and, rarely, neither. The number of times a cat digs before or after eliminating varies considerably among cats and even may vary from time to time for an individual cat. This sequence develops early, at about 4 weeks of age, when kittens begin digging and eliminating in loose, particulate material. It is not necessary for the mother cat to teach the kittens to use litter, because they will do so without ever having observed the mother use the litter. 4 It is not known exactly why cats "cover-up" in litter. One possibility is that burying the feces reduces the possibility of parasite infestation, but no evidence is available to support this theory. It is unclear why burying behavior did not evolve in other groups of animals. It is unlikely that burying evolved to remove the odor of feces, because cats frequently dig, cover, and walk away without completely covering the feces. The behavior sequence terminates despite the continuation of olfactory stimulation.
CAT ELIMINATION BEHAVIOR PROBLEMS
259
STIMULI THAT INFLUENCE ELIMINATION BEHAVIOR A variety of stimuli interact to determine when and where a cat eliminates. Obviously, bowel and bladder sensations are important in motivating elimination behavior. Once motivated to eliminate, surface or location preferences and aversions play a major role. In the natural environment, cats have a choice of numerous surfaces on which to dig, cover, and eliminate, such as loose soil, leaf litter, sand, and so forth. For the domestic cat living in the human household, the surfaces available are limited to commercial litter. Observations of cats in the home and histories of cat elimination problems strongly suggest that tactile/kinesthetic feedback from the paws plays a major role in eliciting and controlling the diggingelimination-covering sequence. Some data supporting this view are presented later in this article. Litter (Surface) Aversion An elimination problem (urination or defecation) frequently is caused by the cat' s aversion to digging and covering in the litter provided by the owner. The cat typically does not cover up the feces and displays behaviors indicating that it dislikes the litter. For instance, the cat may straddle the edge of the litter box to avoid touching the litter with its feet; shake its paws after stepping out of the box; dig outside of the box on the wall, floor of the room, or side of the box; quickly run out of the box; or cry or meow on its way to the box. A cat may find the litter intensely aversive and fail to dig, cover, and eliminate at all in it. A cat may find the litter mildly aversive and use it most of the time, only occasionally eliminating elsewhere or may even use it all of the time but indicate its aversion by its pre-elimination and postelimination behavior. Aversion-related behavior is a good predictor that a cat that now uses the litter box all of the time is likely to eliminate outside of the box at some time in the future. A frequent factor in the onset of a litter aversion is the owner switching to a new type of litter, particularly one that is deodorized or is more dusty than the previous litter. Usually, litter aversions appear to be caused by unlearned individual differences in tactile/kinesthetic sensations from the litter itself, but aversions also could be learned. For example, a cat that has diarrhea in the litter and then gets its paws dirty from covering up in the previously acceptable litter may develop an aversion to that type of litter and may continue eliminating elsewhere even when given fresh litter. This type of problem, however, usually involves evidence of a history of mild litter aversion. Surface Preference
If a cat uses the litter box all of the time but displays digging and covering behavior on a surface other than litter, it may learn to prefer that
260
PETER
L. BORCHELT
surface and ultimately may eliminate on it. For instance, a cat that digs and covers on a bath mat near the litter box may eventually eliminate on the bath mat and then on carpets when the owner makes the bath mat unavailable. A surface preference does not have to be learned (by many pairings of digging and covering behavior with elimination). A cat immediately may prefer the feel of a new carpet or rug when it is first introduced into the home or when the cat first walks on it. Owners mistakenly attribute the elimination behavior on the new surface as marking, whereas the cat simply prefers it to the available litter. Usually in these cases there is evidence of at least a mild litter aversion. Location Preference Animals often engage in certain behaviors in specific locations in their environment. Cats sleep, groom, and sun themselves in certain favorite places and obviously know where to run when the can opener is operated. Generally, a cat' s preferences (or aversions) to the surface features of litter are primary reasons in determining when and where it will eliminate, but location can play an important role as well. A cat that eliminates out of the litter box may do so on one or a few spots or areas. Perhaps the best example of location preferences for elimination is the cat that urinates or defecates on a wall-to-wall carpet but only in one corner. The cat prefers a specific location despite the same tactile characteristics throughput the room. Occasionally, cats that consistently used the box are reported to eliminate on the floor (a new surface) on the exact location of the box when it was moved to a new location. Location Aversions A number of factors can lead to a cat developing an aversion to the litter box or its location. The cat will avoid a location (box) with a strong odor because of insufficient cleaning. A cat that urinates on one corner of the rug eventually will move to a nearby spot after odor at the original spot becomes too strong. Other common sources of location aversions include a cat being frightened in or near the box, a cover placed on the box, or painful elimination in the box.
STIMULI THAT INFLUENCE MARKING Numerous factors can cause urine marking (spraying) in the home. A cat may be competitive, aggressive, or afraid of another cat that is either outdoors or in the home. An outdoor cat can cause the indoor cat to urine mark either by depositing urine on or near the home or by merely being seen or heard by the indoor cat. If this is the cause of the problem, the indoor cat usually will exhibit clear signs of aggressive behavior (e.g., running to the windows or doors, hissing, or growling), defensive behavior
CAT ELIMINATION BEHAVIOR PROBLEMS
261
(piloerection, hissing, growling, running away), or may merely show intense interest by watching the outdoor cat. Similarly, competitive interactions between and among indoor cats can elicit urine marking. The introduction of a new cat or, frequently, the maturation of kittens into adulthood (about 2-3 years of age) can induce marking. Emotionally Related Elimination
In addition to urine marking, in which it is reasonable to assume a cat is emotionally aroused to some degree, a cat may eliminate out of the litter box when separated from the owner for several days or more, if frightened in or around the litter box, or because of the presence of a new person or animal in the home. TREATMENT PLANS FOR ELIMINATION PROBLEMS
A systematic scheme for diagnosing elimination problems and constructing treatment programs has been presented. 4 A variety of behavioral, environmental, pharmacologic, and neurologic techniques were described for both marking and urination and defecation problems. Some new developments in pharmacologic approaches are provided in the. article by Marder elsewhere in this issue. Recent data1 on cats' preferences for different litter materials suggest environmental manipulations that have been quite successful in treating litter aversion problems and some cases of urine marking.
NEW DATA ON PREFERENCES FOR LITTER MATERIALS
In clinical cases in which a cat obviously is averse to the litter, the logical environmental manipulation is to seek a litter material that the cat will prefer (i.e., dig and cover in). The consensus among applied animal behaviorists is that although some cats do show clear preferences, there is little difference among standard commercial clay-based cat litters. These litters vary with respect to deodorants and additives, absorbency of the clay, and amount of dust, but all have about the same range of particle sizes (from about 5-6 mm to dust). Most cases of litter aversion are not treated successfully by switching to another brand of commercial clay-based litter. A number of other types of litter materials, such as wood chips, sand, and topsoil, have been tried with varying degrees of success. A higher success rate has been reported using "sandlike" clay litter with uniformly small particles. A data-based comparison of these materials would be a logical first step in understanding the stimuli involved in cat elimination behavior and might aid in treatment of elimination problems. The Bide-a-wee Home Association in Westhampton, New York pro-
262
PETER
L.
BORCHELT
vided space and cats for a comparison of 14 types of commercial litter materials as well as topsoil mixed with clay litter and playbox sand. Three different comparisons were made over approximately 6 months. Cats were housed individually in six dog runs, each measuring 1 m high X 1 m wide X 2 m long. Each run contained six litter boxes, a carpet-covered "cat condo," and food and water (presented ad libitum). Each litter box contained a different type of litter material covering the litter box to a depth of about 6 to 8 em. Each litter box was checked three times per day for 10 days, and the presence of urine or feces was recorded on data sheets. Urine and feces were removed at each observation. The litter was replaced as necessary. Either two or four groups (12 or 24 cats) were tested with each type of litter material. Litter boxes were washed with soap and water between groups and occasionally were washed before the end of each 10-day observation period to prevent noticeable odor if the litter was used frequently. After the last observation on day 5, the location of the litter boxes was changed to control for possible location preferences. The first comparison used four groups of cats (N = 24). The litters compared were Scamp, Fresh Step, Cats Meow, Hartz Mountain, Jonny Cat, and Everclean. There was no difference between urinating and defecating and the data were combined into total number of eliminations. Table 1 shows the number and percentage of eliminations in each litter for each group of cats and the total for all groups. If cats were to choose litter randomly, e·ach litter would be used about 16% to 17% of the time. Everclean was the only litter consistently chosen more frequently than chance would allow. The second comparison used two groups of cats (N = 12) to compare Everclean with two other clay-based litters (Kitty Litter and Soft Paw) as well as three nonclay litter materials (wood shavings, KatGo, and a 4:1 mixture of Hartz Mountain and topsoil). Table 2 shows the number and percentage of eliminations in each litter for each group of cats and the total for all groups. The only litter chosen more frequently than expected was Everclean. Surprisingly, the wood-product litter was not used at all. Owners report that some cats do prefer wood shavings or chips as litter materials, and an Table I. Results of Comparisons of Litter Preference Among Four Groups of Cats (N = 24) NO. OF ELIMINATIONS(%) LITIER
Group 1
Group 2
Group 3
Group 4
Scamp Fresh Step Cat's Meow Hartz Mntn Jonny Cat Everclean
4 (0.03) 8 (0.06) 6 (0.04) 36 (0.26) 13 (0.09) 73 (0.52)
31 26 18 13 11 63
37 20 3 6 7 102
29 25 12 12 18 93
(0.19) (0.16) (0.11) (0.08) (0.07) (0.39)
(0.21) (0.11) (0.02) (0.03) (0.04) (0.58)
(0.15) (0.13) (0.06) (0.06) (0.10) (0.49)
Total 101 79 39 67 49 331
(0.15) (0.12) (0.06) (0.10) (0.07) (0.50)
263
CAT EUMINATION BEHAVIOR PROBLEMS
Table 2. Results of Comparisons of Litter Material Preference in Two Groups of Cats (N = 12) NO. OF ELIMINATIONS(%) LITIER
Everclean Kitty Litter Wood chips Kat Go Topsoil/Hartz Soft Paw
Group 1
Group 2
146 12 0 0 15 21
90 43 0 0 5 18
(0.75) (0.06) (0.08) (0.11)
(0.58) (0.28) (0.03) (0.12)
Total 236 (0.67) 55 (0.16) 0 0 20 (0.06) 39 (0.11)
occasional litter aversion problem can be treated by offering the cat the choice of a wood-product litter. Many times, however, wood-product litters are rejected by cats exhibiting litter aversion problems. The third comparison used two groups of cats (N = 12) to compare Everclean with playbox sand, Litter Green, Yesterday's News, Control, and Cat Works. Table 3 shows the number and percentage of eliminations in each litter for each group of cats and the total for all groups. Sand was used slightly more frequently than expected and was used more frequently than Control (a coarse clay), but Everclean was used about twice as frequently as sand. The large-grained litter materials (Yesterday's News, Litter Green, and Cat Works) were used rarely. These data support the clinical observation that an important factor· in cats' preference for litter material is its texture, granularity, or coarseness. Everclean, a finely textured clay, was preferred to clay with larger particle sizes. But playbox sand, which also is finely textured, was not preferred much more than coarse clay, perhaps because of the weight of the particles (kinesthetic properties). Litters that had larger particle sizes, such as Yesterday's News, Litter Green, and Cat Works, generally were avoided. INTERACTIONS BETWEEN ODOR, LITTER AVERSION, AND MARKING A cat with a marking behavior problem may have begun spraying while in the litter box and then gradually extended the range of marking locations Table 3. Results of Comparison of Litter Material Preference in Two Groups of Cats (N = 12) NO. OF ELIMINATIONS(%) LITIER
Everclean Yesterday's News Litter Green Playbox sand Control Cat Works
Group 1
Group 2
Total
75 (0.44) 0 1 40 (0.24) 53 (0.31) 0
128 (0.64) 1 0 59 (0.29) 13 (0.06) 0
203 (0.55) 1 1 99 (0.27) 66 (0.18) 0
264
PETER
L.
BORCHELT
to many places throughout the house. In a number of such cases, the cat had a previous history of pre-elimination and postelimination litter aversion behavior. For many of these problems, there is no evidence of competitive interactions between indoor cats and no possibility of interaction with outdoor cats. For instance, some of these problems involve single cats living on the upper floors of high-rise apartment buildings with no neighbor cats. It appears that because of a litter aversion, the cat may have begun marking while in the litter box (but the urine hit the wall or floor) or begun urinating outside of the box. In either case, the odor of its own urine throughout the house elicits further marking behavior. These problems may be refractory to behavioral or pharmacologic treatment, but the introduction of a finely textured litter (such as Everclean) has been quite successful.
REFERENCES 1. Borchelt PL: What kinds(s) of litters do cats prefer. Presented at Animal Behavior Society Meeting, Binghamton, NY, 1990 2. Borchelt PL, Voith VL: Elimination behavior problems in cats. Compend Contin Educ Pract Vet 3:730-737, 1981 3. Borchelt PL, Voith VL: Analysis and treatment of elimination behavior problems in cats. Vet Clin North Am Small Anim Pract 12:673-680, 1982 4. Borchelt PL, Voith VL: Elimination behavior problems in cats. Compend Cantin Educ Pract Vet 8:197-205, 1986 5. Leyhausen P: Cat Behavior. New York, STPM Press, 1979 6. Voith VL: Analysis of 2500 telephone calls about behavior problems of dogs and cats. Presented at the Animal Behavior Society Meeting, Raleigh, NC, 1985 7. Voith VL: Attachment of people to companion animals. Vet Clin North Am Small Anim Pract 15:289-295, 1985 8. Voith VL, Borchelt PL: Social behavior of domestic cats. Compend Cantin Educ Pract Vet 8:637-644, 1986
Address reprint requests to Peter L. Borchelt, PhD Animal Behavior Consultants, Inc. 2465 Stuart Street Brooklyn, NY 11229
0195---5616/91 $0.00
+
.20
Cat Elimination Behavior Problems
Peter L. Borchelt, PhD*
Cats have a generally well-deserved reputation of being naturally clean animals that readily learn to use a litter box. Data from a questionaire 7 filled out by more than 800 cat owners indicated that about one-half reported their cat(s) engaged in one or more problem behaviors and that about one quarter of these owners reported that their cat(s) eliminated out of the litter box at least some of the time. Thus, a conservative estimate is that at least 10% of pet cats at some time exhibit an elimination behavior problem. There are few data available regarding the correlation between breeds of cats and behavior problems, including elimination, .but some preliminary information has been presented. 6 General discussions of marking, urination, and defecation, the specific postures used for each behavior, and procedures for diagnosis and treatment have been presented elsewhere2-4 and are discussed here only briefly. This article provides some new information about cats' preferences for different types of litter materials. When a cat is presented to the veterinarian with elimination behavior problems, it is prudent to consider disease processes in the differential diagnosis. This article focuses only on behavior problems for which pathophysiologic causes have been ruled out.
BEHAVIORAL DESCRIPTION AND DEFINITION Posture Either a standing or a squatting posture can be used for voiding urine. Spraying or urine marking occurs in a standing posture with the hind legs straight and the tail upright and typically quivering while the cat steps alternately with the hind legs. Urine is sprayed horizontally onto vertical surfaces such as walls, table legs, bed ruffies, stereo speakers, and so forth. *Private Practitioner, Animal Behavior Consultants, Inc., Brooklyn, New York Veterinary Clinics of North America: Small Animal Practice-Val. 21, No. 2, March 1991
257
258
PETER
L.
BORCHELT
Generally, the amount of urine expressed is smaller than is voided during typical urination. When urinating or defecating, the hind legs are flexed and waste products are deposited onto horizontal surfaces such as litter boxes (ideally), floors, carpets, beds, couches, and so forth. Function and Context Urine marking generally is thought to have a communicative function because it occurs in the context of territorial, sexual, or agonistic behavior. Urine marking can occur when there are competitive interactions among and between cats within the household, between indoor and outdoor cats, and, rarely, between household cats and humans. The interaction involves some degree of obvious aggression or defensive displays by the cat. 5• 8 Urinating voids the bladder of urine and functions to remove waste products and relieve bladder muscle tension. It usually does not involve the same contexts and motivation as does marking. Defecating voids solid waste products and relieves bowel muscle tension, and usually does not serve as a marking or communicative behavior in domestic cats. Sequences of Behavior As with every other behavior system, elimination is composed of sequences of species-typical behaviors. The sequence of elimination behavior in domestic cats has been described2--4, 6 as approaching a specific .surface or location, digging with the forepaws to make a depression in the substrate, and eliminating, followed by sweeping and pawing motions of the forepaws to cover up the urine or feces. Individual cats vary in the occurrence and frequency of specific components of this sequence. Some owners report that a cat may not dig and cover in the litter box after urinating but simply walks into the box, squats, urinates, and then walks away. Some cats dig and scratch to varying degrees on the floor, wall, or side of the box. A cat may dig in the litter (or elsewhere) before eliminating and not afterward, afterward and not before, both before and after, and, rarely, neither. The number of times a cat digs before or after eliminating varies considerably among cats and even may vary from time to time for an individual cat. This sequence develops early, at about 4 weeks of age, when kittens begin digging and eliminating in loose, particulate material. It is not necessary for the mother cat to teach the kittens to use litter, because they will do so without ever having observed the mother use the litter. 4 It is not known exactly why cats "cover-up" in litter. One possibility is that burying the feces reduces the possibility of parasite infestation, but no evidence is available to support this theory. It is unclear why burying behavior did not evolve in other groups of animals. It is unlikely that burying evolved to remove the odor of feces, because cats frequently dig, cover, and walk away without completely covering the feces. The behavior sequence terminates despite the continuation of olfactory stimulation.
CAT ELIMINATION BEHAVIOR PROBLEMS
259
STIMULI THAT INFLUENCE ELIMINATION BEHAVIOR A variety of stimuli interact to determine when and where a cat eliminates. Obviously, bowel and bladder sensations are important in motivating elimination behavior. Once motivated to eliminate, surface or location preferences and aversions play a major role. In the natural environment, cats have a choice of numerous surfaces on which to dig, cover, and eliminate, such as loose soil, leaf litter, sand, and so forth. For the domestic cat living in the human household, the surfaces available are limited to commercial litter. Observations of cats in the home and histories of cat elimination problems strongly suggest that tactile/kinesthetic feedback from the paws plays a major role in eliciting and controlling the diggingelimination-covering sequence. Some data supporting this view are presented later in this article. Litter (Surface) Aversion An elimination problem (urination or defecation) frequently is caused by the cat' s aversion to digging and covering in the litter provided by the owner. The cat typically does not cover up the feces and displays behaviors indicating that it dislikes the litter. For instance, the cat may straddle the edge of the litter box to avoid touching the litter with its feet; shake its paws after stepping out of the box; dig outside of the box on the wall, floor of the room, or side of the box; quickly run out of the box; or cry or meow on its way to the box. A cat may find the litter intensely aversive and fail to dig, cover, and eliminate at all in it. A cat may find the litter mildly aversive and use it most of the time, only occasionally eliminating elsewhere or may even use it all of the time but indicate its aversion by its pre-elimination and postelimination behavior. Aversion-related behavior is a good predictor that a cat that now uses the litter box all of the time is likely to eliminate outside of the box at some time in the future. A frequent factor in the onset of a litter aversion is the owner switching to a new type of litter, particularly one that is deodorized or is more dusty than the previous litter. Usually, litter aversions appear to be caused by unlearned individual differences in tactile/kinesthetic sensations from the litter itself, but aversions also could be learned. For example, a cat that has diarrhea in the litter and then gets its paws dirty from covering up in the previously acceptable litter may develop an aversion to that type of litter and may continue eliminating elsewhere even when given fresh litter. This type of problem, however, usually involves evidence of a history of mild litter aversion. Surface Preference
If a cat uses the litter box all of the time but displays digging and covering behavior on a surface other than litter, it may learn to prefer that
260
PETER
L. BORCHELT
surface and ultimately may eliminate on it. For instance, a cat that digs and covers on a bath mat near the litter box may eventually eliminate on the bath mat and then on carpets when the owner makes the bath mat unavailable. A surface preference does not have to be learned (by many pairings of digging and covering behavior with elimination). A cat immediately may prefer the feel of a new carpet or rug when it is first introduced into the home or when the cat first walks on it. Owners mistakenly attribute the elimination behavior on the new surface as marking, whereas the cat simply prefers it to the available litter. Usually in these cases there is evidence of at least a mild litter aversion. Location Preference Animals often engage in certain behaviors in specific locations in their environment. Cats sleep, groom, and sun themselves in certain favorite places and obviously know where to run when the can opener is operated. Generally, a cat' s preferences (or aversions) to the surface features of litter are primary reasons in determining when and where it will eliminate, but location can play an important role as well. A cat that eliminates out of the litter box may do so on one or a few spots or areas. Perhaps the best example of location preferences for elimination is the cat that urinates or defecates on a wall-to-wall carpet but only in one corner. The cat prefers a specific location despite the same tactile characteristics throughput the room. Occasionally, cats that consistently used the box are reported to eliminate on the floor (a new surface) on the exact location of the box when it was moved to a new location. Location Aversions A number of factors can lead to a cat developing an aversion to the litter box or its location. The cat will avoid a location (box) with a strong odor because of insufficient cleaning. A cat that urinates on one corner of the rug eventually will move to a nearby spot after odor at the original spot becomes too strong. Other common sources of location aversions include a cat being frightened in or near the box, a cover placed on the box, or painful elimination in the box.
STIMULI THAT INFLUENCE MARKING Numerous factors can cause urine marking (spraying) in the home. A cat may be competitive, aggressive, or afraid of another cat that is either outdoors or in the home. An outdoor cat can cause the indoor cat to urine mark either by depositing urine on or near the home or by merely being seen or heard by the indoor cat. If this is the cause of the problem, the indoor cat usually will exhibit clear signs of aggressive behavior (e.g., running to the windows or doors, hissing, or growling), defensive behavior
CAT ELIMINATION BEHAVIOR PROBLEMS
261
(piloerection, hissing, growling, running away), or may merely show intense interest by watching the outdoor cat. Similarly, competitive interactions between and among indoor cats can elicit urine marking. The introduction of a new cat or, frequently, the maturation of kittens into adulthood (about 2-3 years of age) can induce marking. Emotionally Related Elimination
In addition to urine marking, in which it is reasonable to assume a cat is emotionally aroused to some degree, a cat may eliminate out of the litter box when separated from the owner for several days or more, if frightened in or around the litter box, or because of the presence of a new person or animal in the home. TREATMENT PLANS FOR ELIMINATION PROBLEMS
A systematic scheme for diagnosing elimination problems and constructing treatment programs has been presented. 4 A variety of behavioral, environmental, pharmacologic, and neurologic techniques were described for both marking and urination and defecation problems. Some new developments in pharmacologic approaches are provided in the. article by Marder elsewhere in this issue. Recent data1 on cats' preferences for different litter materials suggest environmental manipulations that have been quite successful in treating litter aversion problems and some cases of urine marking.
NEW DATA ON PREFERENCES FOR LITTER MATERIALS
In clinical cases in which a cat obviously is averse to the litter, the logical environmental manipulation is to seek a litter material that the cat will prefer (i.e., dig and cover in). The consensus among applied animal behaviorists is that although some cats do show clear preferences, there is little difference among standard commercial clay-based cat litters. These litters vary with respect to deodorants and additives, absorbency of the clay, and amount of dust, but all have about the same range of particle sizes (from about 5-6 mm to dust). Most cases of litter aversion are not treated successfully by switching to another brand of commercial clay-based litter. A number of other types of litter materials, such as wood chips, sand, and topsoil, have been tried with varying degrees of success. A higher success rate has been reported using "sandlike" clay litter with uniformly small particles. A data-based comparison of these materials would be a logical first step in understanding the stimuli involved in cat elimination behavior and might aid in treatment of elimination problems. The Bide-a-wee Home Association in Westhampton, New York pro-
262
PETER
L.
BORCHELT
vided space and cats for a comparison of 14 types of commercial litter materials as well as topsoil mixed with clay litter and playbox sand. Three different comparisons were made over approximately 6 months. Cats were housed individually in six dog runs, each measuring 1 m high X 1 m wide X 2 m long. Each run contained six litter boxes, a carpet-covered "cat condo," and food and water (presented ad libitum). Each litter box contained a different type of litter material covering the litter box to a depth of about 6 to 8 em. Each litter box was checked three times per day for 10 days, and the presence of urine or feces was recorded on data sheets. Urine and feces were removed at each observation. The litter was replaced as necessary. Either two or four groups (12 or 24 cats) were tested with each type of litter material. Litter boxes were washed with soap and water between groups and occasionally were washed before the end of each 10-day observation period to prevent noticeable odor if the litter was used frequently. After the last observation on day 5, the location of the litter boxes was changed to control for possible location preferences. The first comparison used four groups of cats (N = 24). The litters compared were Scamp, Fresh Step, Cats Meow, Hartz Mountain, Jonny Cat, and Everclean. There was no difference between urinating and defecating and the data were combined into total number of eliminations. Table 1 shows the number and percentage of eliminations in each litter for each group of cats and the total for all groups. If cats were to choose litter randomly, e·ach litter would be used about 16% to 17% of the time. Everclean was the only litter consistently chosen more frequently than chance would allow. The second comparison used two groups of cats (N = 12) to compare Everclean with two other clay-based litters (Kitty Litter and Soft Paw) as well as three nonclay litter materials (wood shavings, KatGo, and a 4:1 mixture of Hartz Mountain and topsoil). Table 2 shows the number and percentage of eliminations in each litter for each group of cats and the total for all groups. The only litter chosen more frequently than expected was Everclean. Surprisingly, the wood-product litter was not used at all. Owners report that some cats do prefer wood shavings or chips as litter materials, and an Table I. Results of Comparisons of Litter Preference Among Four Groups of Cats (N = 24) NO. OF ELIMINATIONS(%) LITIER
Group 1
Group 2
Group 3
Group 4
Scamp Fresh Step Cat's Meow Hartz Mntn Jonny Cat Everclean
4 (0.03) 8 (0.06) 6 (0.04) 36 (0.26) 13 (0.09) 73 (0.52)
31 26 18 13 11 63
37 20 3 6 7 102
29 25 12 12 18 93
(0.19) (0.16) (0.11) (0.08) (0.07) (0.39)
(0.21) (0.11) (0.02) (0.03) (0.04) (0.58)
(0.15) (0.13) (0.06) (0.06) (0.10) (0.49)
Total 101 79 39 67 49 331
(0.15) (0.12) (0.06) (0.10) (0.07) (0.50)
263
CAT EUMINATION BEHAVIOR PROBLEMS
Table 2. Results of Comparisons of Litter Material Preference in Two Groups of Cats (N = 12) NO. OF ELIMINATIONS(%) LITIER
Everclean Kitty Litter Wood chips Kat Go Topsoil/Hartz Soft Paw
Group 1
Group 2
146 12 0 0 15 21
90 43 0 0 5 18
(0.75) (0.06) (0.08) (0.11)
(0.58) (0.28) (0.03) (0.12)
Total 236 (0.67) 55 (0.16) 0 0 20 (0.06) 39 (0.11)
occasional litter aversion problem can be treated by offering the cat the choice of a wood-product litter. Many times, however, wood-product litters are rejected by cats exhibiting litter aversion problems. The third comparison used two groups of cats (N = 12) to compare Everclean with playbox sand, Litter Green, Yesterday's News, Control, and Cat Works. Table 3 shows the number and percentage of eliminations in each litter for each group of cats and the total for all groups. Sand was used slightly more frequently than expected and was used more frequently than Control (a coarse clay), but Everclean was used about twice as frequently as sand. The large-grained litter materials (Yesterday's News, Litter Green, and Cat Works) were used rarely. These data support the clinical observation that an important factor· in cats' preference for litter material is its texture, granularity, or coarseness. Everclean, a finely textured clay, was preferred to clay with larger particle sizes. But playbox sand, which also is finely textured, was not preferred much more than coarse clay, perhaps because of the weight of the particles (kinesthetic properties). Litters that had larger particle sizes, such as Yesterday's News, Litter Green, and Cat Works, generally were avoided. INTERACTIONS BETWEEN ODOR, LITTER AVERSION, AND MARKING A cat with a marking behavior problem may have begun spraying while in the litter box and then gradually extended the range of marking locations Table 3. Results of Comparison of Litter Material Preference in Two Groups of Cats (N = 12) NO. OF ELIMINATIONS(%) LITIER
Everclean Yesterday's News Litter Green Playbox sand Control Cat Works
Group 1
Group 2
Total
75 (0.44) 0 1 40 (0.24) 53 (0.31) 0
128 (0.64) 1 0 59 (0.29) 13 (0.06) 0
203 (0.55) 1 1 99 (0.27) 66 (0.18) 0
264
PETER
L.
BORCHELT
to many places throughout the house. In a number of such cases, the cat had a previous history of pre-elimination and postelimination litter aversion behavior. For many of these problems, there is no evidence of competitive interactions between indoor cats and no possibility of interaction with outdoor cats. For instance, some of these problems involve single cats living on the upper floors of high-rise apartment buildings with no neighbor cats. It appears that because of a litter aversion, the cat may have begun marking while in the litter box (but the urine hit the wall or floor) or begun urinating outside of the box. In either case, the odor of its own urine throughout the house elicits further marking behavior. These problems may be refractory to behavioral or pharmacologic treatment, but the introduction of a finely textured litter (such as Everclean) has been quite successful.
REFERENCES 1. Borchelt PL: What kinds(s) of litters do cats prefer. Presented at Animal Behavior Society Meeting, Binghamton, NY, 1990 2. Borchelt PL, Voith VL: Elimination behavior problems in cats. Compend Contin Educ Pract Vet 3:730-737, 1981 3. Borchelt PL, Voith VL: Analysis and treatment of elimination behavior problems in cats. Vet Clin North Am Small Anim Pract 12:673-680, 1982 4. Borchelt PL, Voith VL: Elimination behavior problems in cats. Compend Cantin Educ Pract Vet 8:197-205, 1986 5. Leyhausen P: Cat Behavior. New York, STPM Press, 1979 6. Voith VL: Analysis of 2500 telephone calls about behavior problems of dogs and cats. Presented at the Animal Behavior Society Meeting, Raleigh, NC, 1985 7. Voith VL: Attachment of people to companion animals. Vet Clin North Am Small Anim Pract 15:289-295, 1985 8. Voith VL, Borchelt PL: Social behavior of domestic cats. Compend Cantin Educ Pract Vet 8:637-644, 1986
Address reprint requests to Peter L. Borchelt, PhD Animal Behavior Consultants, Inc. 2465 Stuart Street Brooklyn, NY 11229
