Agonistic behavior and environmental enrichment of cats communally housed in a shelter

Leticia M. S. Dantas-Divers Programa de Pós-Graduação em Medicina Veterinária (Clinica e Reprodução Animal), College of Veterinary Medicine, Universidade Federal Fluminense, Niteroi, RJ 24320-340, Brazil.
Department of Anatomy and Radiology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

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Sharon L. Crowell-Davis Department of Anatomy and Radiology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

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Kelly Alford Department of Anatomy and Radiology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

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Gelson Genaro Programa de Pós Graduação em Psicobiologia, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirao Preto, SP 14040-030, Brazil.

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Jose Mario D'Almeida Departamento de Biologia Geral, Instituto de Biologia, Universidade Federal Fluminense, Niteroi, RJ 24020-140, Brazil.

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Rita L. Paixao Departamento de Fisiologia e Farmacologia, Institutio Biomedico, Universidade Federal Fluminense, Niteroi, RJ 24210-110, Brazil.

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Abstract

Objective—To evaluate the presence of a dominance rank in a group of cats and the relation between agonistic behavior and the use of resources, including environmental enrichment, in these cats.

Design—Observational analytic study.

Animals—27 neutered cats in a shelter in Sao Paulo, Brazil.

Procedures—The cats were video recorded for 4 consecutive days to obtain baseline data. Subsequently, a puzzle feeder was added as an enrichment device every other day over 8 days, for a total of 4 days with enrichment. Cats were also video recorded on these days. All pretreatment and posttreatment agonistic behaviors and interactions with the puzzle feeder were recorded by reviewing the videotapes.

Results—143 agonistic encounters were recorded, of which 44 were related to resources and 99 were not. There were insufficient agonistic interactions to determine a dominance rank. Presence or absence of the puzzle feeder did not affect the rate of aggression. There was no significant effect of weight, sex, or coat color on the rate of aggression, and aggressive behavior did not correlate with time spent with the puzzle feeder. Twenty-three of the 27 cats interacted with the puzzle feeder.

Conclusions and Clinical Relevance—In a stable group of communally housed cats, environmental enrichment did not cause increased aggression as a result of competition for the source of enrichment. Because environmental enrichment increases the opportunity to perform exploratory behaviors, it may improve the welfare of groups of cats maintained long-term in shelters, sanctuaries, or multicat households.

Abstract

Objective—To evaluate the presence of a dominance rank in a group of cats and the relation between agonistic behavior and the use of resources, including environmental enrichment, in these cats.

Design—Observational analytic study.

Animals—27 neutered cats in a shelter in Sao Paulo, Brazil.

Procedures—The cats were video recorded for 4 consecutive days to obtain baseline data. Subsequently, a puzzle feeder was added as an enrichment device every other day over 8 days, for a total of 4 days with enrichment. Cats were also video recorded on these days. All pretreatment and posttreatment agonistic behaviors and interactions with the puzzle feeder were recorded by reviewing the videotapes.

Results—143 agonistic encounters were recorded, of which 44 were related to resources and 99 were not. There were insufficient agonistic interactions to determine a dominance rank. Presence or absence of the puzzle feeder did not affect the rate of aggression. There was no significant effect of weight, sex, or coat color on the rate of aggression, and aggressive behavior did not correlate with time spent with the puzzle feeder. Twenty-three of the 27 cats interacted with the puzzle feeder.

Conclusions and Clinical Relevance—In a stable group of communally housed cats, environmental enrichment did not cause increased aggression as a result of competition for the source of enrichment. Because environmental enrichment increases the opportunity to perform exploratory behaviors, it may improve the welfare of groups of cats maintained long-term in shelters, sanctuaries, or multicat households.

As demonstrated by several surveys, growth of the owned domestic cat populations in the world parallels the number of cats that are euthanized, relinquished to shelters and animal control facilities, or simply abandoned.1,2 Various approaches have been attempted to reverse or at least control this problem, from spaying and neutering programs for owned cats and trap-neuter-return projects for feral cats to educational campaigns for schools and communities.3 Nevertheless, a solution for the overpopulation of cats and the damage to the human-animal bond leading to relinquishment and euthanasia of healthy animals remains elusive. Groups of cats living in shelters are a reality all over the world, and shelter medicine is a rapidly expanding area of veterinary medicine, often challenged with a lack of resources to improve animal welfare.4

One of the most challenging issues to address to improve the welfare of confined cats is providing an adequate environment to meet cognitive and social needs of the species.5 Much of domestic cat behavior needs further investigation, but a concept that has been specifically challenged in social behavioral studies6 is dominance. Even a consensus on its definition and how to identify it in a group is rarely achieved.7 Dominance relationships refer to dyads of individuals in which one (the loser or submissive individual) consistently submits or gives way to another individual as a consequence of prior experience with that individual (the winner or dominant individual).7 If that definition is to be applied when cats live together in the same social group, a set of dominant-subordinate relationships among pairs of cats that interact sufficiently can be identified.8 However, a hierarchy or social rank cannot always be determined in groups of cats.a Authors who have used the concept of hierarchy relationships to describe cat social behavior understand that the major function of dominance is presumably to allow priority of access to preferred resources, such as food, water, resting sites, and mates. However, the dominant animal in a group does not always have first and greatest access to these resources.a Other variables, such as motivation to obtain the resource, learned experiences, the relationship developed between a pair, coalitions by multiple animals against 1 animal, behavioral disorders, and several other factors, can contradict this expectation.9 Also, attempts to correlate agonistic behavior and social rank in other species have not always been successful, and it has been argued that one of the functions of a dominance hierarchy is actually to decrease aggression; therefore, aggressive behavior does not necessarily correlate with dominance relationships.7 Actually, once a dominance relationship between 2 animals is established, it will allow individuals to predict the outcome of future encounters and therefore engage in subtle agonistic behaviors that do not result in injury.10 That is one of the reasons the diagnosis of dominance or status-related aggression has been recently debated and even dismissed by some authors in behavioral medicine.6,11

Aggressive behavior toward humans and other cats to is one of the main behavioral reasons for euthanasia and abandonment of cats.2,12 More studies are needed to understand the relationship between aggression and access to resources in this species. Normal agonistic interactions between cats are often subtle and ritualized, instead of overt and injurious.9 Furthermore, the underlying reasons for aggression in cats are more complex than simple access to resources, and other causes have to be taken into consideration for a proper diagnosis to be made.8 Additionally, understanding the social behavior of cats and how their relationships affect access to resources is fundamental to more appropriate management and to improve the welfare of cats in shelters or multicat households.

Environmental enrichment has been one of the most successful techniques for behaviorial modification and improving welfare of confined animals, including cats.13–15 For animals that have been victims of abandonment or abuse, it may also decrease fear of humans via classic conditioning, as cats can learn that people are a source of pleasant, rather than aversive, experiences.5 Inexpensive but effective devices can be developed with reused or low-cost materials, which makes them affordable for shelters.14

The combination of physical and occupational enrichment can also promote social enrichment among conspecifics, one of the most neglected needs of cats in confinement.15 Social contact provides a constant source of complex mental stimulation for which no environment enrichment item can substitute.16 Environment enrichment items that dispense food or that make animals search for food have been recommended for many species.16 Food is a potent reward, and most individuals have a strong drive for foraging and exploratory behavior, which would occupy a substantial part of their time under natural conditions.17 Puzzle feeders and food dispensers have been widely used for felids because these items combine the motivation for feeding and exploring as well as cognitive stimulation.17,18 They might also stimulate play behavior and increase positive social contact among animals.b However, when offering an item to a group, it is necessary to evaluate whether it can be used by most group members. Otherwise, frustration or dispute for this particular resource can take place, leading to an increase in aggressive behavior.16

When designing enrichment for cats in confinement, it has to be kept in mind that group density is directly correlated to stress.4,19,20 It is commonly accepted that space use is more relevant than the size of the area itself.14,15 However, hiding or keeping a distance from other individuals is a main behavior of cats coping with social stress.21 Providing enough retreats and considering individual cat socializations are important when establishing group housing.4,20

The purpose of the study reported here was to evaluate the presence of a dominance rank in a group of cats communally housed in a shelter and to determine the relation between agonistic behavior and the use of resources, including an environmental enrichment puzzle feeder, in these cats.

Materials and Methods

Cats and research site—This study was approved by the Ethical Committee for Animal Research of the Universidade Federal Fluminense. Twenty-seven neutered cats (6 males and 21 females) that had previously been household cats and were subsequently moved to a nonkill shelter in Ribeirao Preto, SP, Brazil, were the subjects of this study. At the shelter, the cats were kept in the same enclosure and it was estimated that they had been living together in the shelter for 3 years. Although they were either adults or seniors, a precise age of the cats was not known. Therefore, age analysis was not done in this study.

The mean weight of male cats was 4.1 kg (9.0 lb; range, 2.9 to 5.0 kg [6.4 to 11.0 lb]), and the mean weight of female cats was 3.9 kg (8.6 lb; range, 2.0 to 6.4 kg [4.4 to 14.1 lb]). All cats received treatment for ectoparasites and endoparasites and had been vaccinated (panleukopenia, rhinotracheitis, calicivirus, and rabies) prior to the study. Testing for FIV and FeLV was not performed because of economic constraints. During the course of this study, none of the cats appeared to be ill or have clinical signs of either of these diseases. The shelter had 1 other confined area with another group of cats, 5 enclosures for dogs, and 1 external area with free-ranging cats. It was located in a mixed residential and commercial neighborhood. Adult cat dry food and water were available for the cats ad libitum.

The cats were kept in an enclosure that had an interior and exterior section. They could move between the 2 sections via 2 large openings (1.93 × 0.76 m). The total area of the enclosure was 24.82 m2. The outside run had a ground area of 13.26 m2 and contained 3 tables, a plastic chair, a swing, a tree trunk, and 2 shelves that served as elevated spaces for the cats. The interior area of the enclosure had a floor area of 11.56 m2, 16 plastic baskets that served as beds, two 1.30-m shelves that ran the length of each side wall, and a 2.67-m food trough in the center of the room. Summing the measurements of the elevated spaces with the ground area, the total area of the enclosure was 34.09 m2 (1.26 m2/cat). The cats also had a sisal scratching post available attached to one of the outside walls. Temperatures ranged from a high of 36°C (97°F) on October 26, 2008, to a high of 29°C (84°F) on November 3, 2008. Nightly low temperatures did not decrease below 19°C (66°F).

Study protocol—The colony was video recorded between October 23 and November 3, 2008. The cats were already habituated to people, but prior to video recording, a 3-month habituation period was used to familiarize the cats with the presence of the researcher in the shelter. Two cameras were installed in the enclosure ceiling: 1 outside and 1 inside. During video recording of baseline behavior, neither the researcher nor anyone else entered the enclosure or interacted with the cats from the outside. When the video recordings were reviewed, all occurrences of agonistic interactions (aggressive and appeasement behaviors) between cats were recorded.22 Data regarding the normal activities of the cats were recorded for 4 consecutive days from 8:30 am to 9:30 am, 10:30 am to 11:30 am, 2:30 pm to 3:30 pm, and 4:30 pm to 5:30 pm each day, for a total of 16 hours.

After baseline video recording was completed, a puzzle feeder was placed in the enclosure for 1 hour on alternate days to avoid habituation.23 The cats' feeding occurred as normally scheduled on the enrichment days. On the first day, the box was left with the cats from 8:30 am to 9:30 am, on the third day from 10:30 am to 11:30 am, on the fifth day from 2:30 pm to 3:30 pm, and on the seventh day from 4:30 pm to 5:30 pm. The puzzle feeder was made of reused disposable materials. It consisted of a plastic storage box (31 × 20 × 10 cm) with nylon strings that held pieces of polyvinylchloride pipe (Figure 1). On the enrichment days, 250 g of commercial dry food and 350 g of wet food were mixed and inserted on the floor of the box, below the polyvinylchloride pieces.

Figure 1—
Figure 1—

Photograph of the puzzle feeder made from a plastic storage box (31 × 20 × 10 cm) and pieces of polyvinylchloride pipe held together by nylon strings.

Citation: Journal of the American Veterinary Medical Association 239, 6; 10.2460/javma.239.6.796

Data and statistical analysis—A list of agonistic behaviors and interactions with the puzzle feeder was developed on the basis of the behaviors of the cats in the study, with reference to ethograms of previous worka (Appendix). Each dyad interaction (ie, pairs of cats with at least 3 agonistic encounters) and each individual cat's behaviors were recorded. Rates of aggressive and appeasement behavior per cat per hour were calculated. Numeric data on affiliative behavior were not recorded because, as the cats curled up together, it was not always possible to identify every individual.

Statistical analysis was performed by use of a statistical program.c Values of P < 0.05 were considered significant, and the Bonferroni correction adjusted the P value for significance to P < 0.008. Because 16 hours of baseline data and 4 hours of treatment (puzzle feeder) data were collected for each cat, for purposes of statistical comparison, the baseline data were divided by 4 so that frequencies of given behaviors every 4 hours could be compared.

A Pearson correlation was used to determine whether there was a correlation between weight and aggression, an independent sample t test was used to determine whether there was a relationship between sex and rate of aggression, and a 1-way ANOVA was used to determine whether there was a relationship between coat color and aggression. To test whether there was a correlation between rate of aggression with and without the puzzle feeder in the enclosure, a paired sample t test was used (ie, each cat's rate of aggression when there was no puzzle feeder present was compared with its rate of aggression when the puzzle feeder was present). A Pearson correlation was also used to determine whether there was a relationship between rate of aggression and time spent interacting with the puzzle feeder (ie, whether more aggressive cats were more likely to show prolonged interest in the puzzle feeder).

To test whether a dominance rank could be defined, the agonistic interactions between cats were recorded; a cat was considered subordinate to another cat only if it lost 3 of 3 interactions or lost 75% of the interactions when > 3 interactions between 2 cats occurred.a The dyadic relationship was then included in the analysis of relationships. This standard was used for interactions related to the puzzle feeder and not related to the puzzle feeder when it was not present.

Results

All cats were involved in at least 1 agonistic encounter as the winner or loser. A total of 143 agonistic encounters among dyads of cats were recorded, of which 44 were related to resources and 99 were unrelated to resources. Of the 143 of agonistic encounters, 29 did not involve any aggression on the winner's part, consisting only of a spontaneous appeasement display from the subordinate cat. Three encounters unrelated to resources had no obvious winner or loser and therefore were not included in calculations. Regarding the agonistic encounters related to resources, 13 were over food, 14 were over a bed, 5 were over elevated spaces, and 12 were related to the puzzle feeder. Although 77 dyads of cats involved in agonistic interactions were recorded, there were insufficient agonistic interactions between cats, related to resources or not, to determine a dominance rank within most dyads. Only 8 dyads had at least 3 or more encounters. Among these 8 dyads, only 2 cats had agonistic encounters related to resources. None of these dyadic interactions were related to the puzzle feeder. Additionally, among these 8 dyads, 5 had the same female (the most aggressive cat) as the winner over other cats, and none of these encounters included a dispute for resources. The aggression rate per cat per hour was 0.2462 (Table 1), and the rate of appeasement behavior was 0.2537 (Table 2).

Table 1—

Individual aggressive behaviors recorded and rate of aggressive behavior per cat per hour in a group of 27 cats communally housed in a shelter.

Aggressive behaviorNo. of events recordedAggression rate (aggressive behaviors/cat/h)*
Paw620.1148
Stare380.0703
Chase150.0277
Block80.0148
Feint40.0074
Bite20.0037
Supplant bed20.0037
Pounce10.0018
Mount10.0018
Total1330.2462

Aggression rate was calculated by dividing the total number of aggressive events by the number of cats (n = 27) and the number of hours of observation (20).

Table 2—

Individual appeasement behaviors recorded and rate of appeasement behavior per cat per hour in a group of 27 cats communally housed in a shelter.

Appeasement behaviorNo. of events recordedAppeasement rate (appeasement behaviors/cat/h)*
Retreat from cat810.1500
Flinch130.0240
Retreat from bed120.0222
Retreat from puzzle feeder70.0129
Move away at food trough50.0092
Wait on food50.0092
Avoid cat30.0055
Give away food20.0037
Retreat from food trough20.0037
Submissive roll20.0037
Retreat from elevated space20.0037
Give away elevated space10.0018
Wait on bed10.0018
Wait on elevated space10.0018
Total1370.2537

Appeasement rate was calculated by dividing the total number of appeasement events by the number of cats (n = 27) and the number of hours of observation (20).

Regarding the presence of the environmental enrichment item in the enclosure, only 4 cats did not interact with the puzzle feeder. Cats were not significantly (P = 0.576) more or less aggressive when the puzzle feeder was present versus when it was absent.

There was no significant (P = 0.864; r = −0.035) correlation between weight and rate of aggression. There was no significant effect of sex (P = 0.882) or coat color (P = 0.561) on the rate of aggression. There was no significant (P = 0.580; r = 0.111) correlation between aggression and time spent interacting with puzzle feeder.

Discussion

The low rate of aggressive behavior and the inadequate number of agonistic encounters to define a dominance hierarchy are interesting. It has been documented that normal agonistic interactions in domestic cats are highly ritualized, probably an adaptation to avoid escalation of aggression and injury to a member of the colony.24,25 Avoidance and appeasement behaviors are more commonly observed than overt aggression.9 In the group of the present study, none of the cats were relatives, which has been shown to increase affiliative behaviors and decrease overt aggression.26 However, these cats did have some degree of familiarity because they had been sharing the same environment for at least 3 years, which might have played a role in the low rate of aggression.8 It has previously been shown that the longer 2 cats have lived together, the lower the rate of agonistic interactions and overt aggression.8

Shelter environments have several features that are known to be extremely stressful to cats (eg, unfamiliar, unpredictable, and impoverished environments; circulation of strange people; presence of dogs and unfamiliar cats; reduced space; behavioral deprivation; and frustration).27 However, after 3 years in the shelter, habituation to the environmental stressors could have happened. Interestingly, the cats in the study not only shared resources with rare displays of aggression, but also displayed frequent affiliative behaviors toward each other (eg, mutual grooming, mutual rubbing, sleeping and resting together, and social play). In 29 of the 143 agonistic encounters recorded, there was no aggression on the winner's part, only spontaneous appeasement behavior from the second cat. Appeasement behavior is normally displayed by the young in many social species to the older members of the group, and it is also a result of a learned response to avoid conflict among members of a group.28

The fact that all animals were neutered might be another contributing factor to the low rate of aggression.8 Reproductive state probably accounts for the difference between the present study and other research involving feral cat colonies where most aggression observed was related to sexual or maternal behavior.25,29 Although castration might be considered an artifact in studies of behavior, most cats evaluated by behavioral services and kept in shelters and even feral populations targeted by trap-neuter-return programs are neutered or spayed. Therefore, these cats comprise a specific type of population that needs further behavioral investigation because most studies on domestic cat behavior have used sexually intact social groups.30

The availability of water and food ad libitum, in a long food trough instead a food bowl, may have contributed to the low rate of aggression, is an example of good management for shelters, and is preferable to keeping cats in individual cages.24 Housing a social species, such as cats, alone had been shown to be a major source of distress in shelters and single-cat households.4,5,13 The possibility of fights due to restricted resources (food, water, shelves, beds, and toys) can be overcome if enough choices are offered to avoid confrontation. Considering the ritualization of agonistic behavior in clinically normal cats, especially if neutered,8 this seems to be an appropriate way to keep cats long-term to improve their welfare.

Among all 143 dyadic agonistic encounters recorded, only 44 were related to resources. The other recorded agonistic encounters did not involve any resources, including the puzzle feeder. Not even the novelty promoted by the enrichment item provoked enough stress or competition to increase aggressive behavior. The lack of sufficient agonistic interactions between pairs of cats to construct a dominance hierarchy could be partially a consequence of methodology, as the rate of aggression was so low that more hours of video recording would have been necessary.a However, relationships between cats are based on mutual recognition and previous experiences.10 The role of improper socialization, common in cats as a result of the brief socialization period (from the third to the eighth week of age),31 and early aversive experiences cannot be overemphasized as part of the etiology of aggressive behavior.32 Cats that have not been properly socialized may develop behaviors ranging from aggressive play to overt aggression.8 Aversive experiences, especially in the first months of life, can also alter an individual's behavior definitively because of learning and the pathophysiologic consequences of stress on the immune system and CNS.33,34 Nevertheless, context and prior experience alone may explain the outcome of encounters in social species.35 Sex, age, reproductive stage, nutritional and health condition (especially if painful), motivation to access a resource, and individual preferences are also other contributing factors to aggressive behavior.6,8

Group density is an important welfare factor for communally housed cats.4,13 The cats in the present study had 1.26 m2/cat, which is below the recommended minimum of 1.7 m2/cat.4 However, the number of vertical spaces and retreats allowed the cats to avoid each other. Cats that are not socialized with other cats are less stressed under single-housing conditions than in group housing.4,20 Although habituation and learning may influence how flexible cats are over time, the role of socialization cannot be disregarded.4,14 To communally house cats that are not socialized to their own species can produce high stress levels that may be persistent, leading to a chronic state of poor welfare.20 Assessing short- and long-term stress is fundamental for assuring that the type of housing provided meets welfare expectations.4,27

A cat's personality is another factor that affects its interactions with the environment and other individuals.36 An animal's personality or behavioral style refers to the distinctiveness of behavior and therefore reactions to aversive events and stress.37 Personalities have been extensively studied not only in primates but also in cats.36,38–40 Evaluating each cat's personality was beyond the scope of the present study. However, it should be taken into consideration in behavioral diagnosis and prognosis. These individual differences have an impact on the likelihood of the development of fear responses and therefore are a component of aggressive behavior.37 For instance, regarding the interactions with the puzzle feeder, only 4 cats did not approach it. Specifically, the 4 cats that did not interact with it were timid individuals (n = 2) or had an extremely fearful body posture toward humans (2).39 However, these cats were frequently observed displaying affiliative behaviors toward other cats. It is possible that they were not interested or motivated to interact with the puzzle feeder or that the presence of other cats might have inhibited their exploratory behavior. Nevertheless, there were times during video recording when the puzzle feeder was not being used by any cat and no cat was close to it, which, in theory, would have given any cat an opportunity to approach if interested; however, in practice, these cats might be inhibited due to fear, conflict, or anxiety, even if other cats were not close to the enrichment item.

These results support the use of a puzzle feeder as environmental enrichment for improving the welfare of confined cats.5,13–15 Most cats in the group used the puzzle feeder, and no aggressive cat controlled or blocked access of other cats, a phenomenon that has been occasionally observed in other species.16 Additionally, there was no correlation between aggressive behavior and the time spent with the puzzle feeder. Finally, the rate of aggression displayed by the cats was not affected by the presence of the puzzle feeder, which is one of the issues that might arise from inserting a new stimulating item in a group environment.16

Sex had no significant effect on aggressive behavior, which is not surprising because all animals were spayed or neutered. The weight of the cats also had no significant correlation to aggressive behavior. Size and weight have been correlated to a higher position in a social rank or to a more aggressive individual in some studies, but that is not commonly observed in cats.a The most aggressive cat in the present study was not only a female but also weighed 3.1 kg (6.8 lb), as opposed to the heaviest cat in the shelter (6.4 kg [148 lb]), also a female.

Likewise, there was no relationship between color of coat and aggression. The association between coat color and behavior has been suggested in several species.30 Although coat color genes are unlikely to affect behavior directly, an association between coat color and tendencies toward fear and aggression has been shown in other carnivores.41 There are still no extensive studies in cats, but some associations between coat color and behavior have been suggested.30

In conclusion, this group of cats, despite the lack of kinship and the stress caused by a shelter environment, proved to be a cohesive social group in which affiliative behavior predominated and aggression rate was rather low. These findings suggest that overt aggression as a strategy to cope with environmental challenges and other individuals is a consequence of stress and emotional states such as fear, anxiety, and pain, rather than a normal social behavior to maintain a social position in the group or have priority access to resources. Factors such as improper socialization, group density, aversive and other learned experiences, context of conflict, motivation to obtain a resource, individual preferences, personality, physiologic state, and medical and other behavioral disorders should be taken into consideration when diagnosing aggressive behavior in cats. These factors seem to play a more important role in intercat aggression than a simple dispute for resources or a social position in a group, as suggested by the classic concept of dominance.6

Sex, weight, and coat color were not predictors of the outcome of aggressive encounters and did not affect the use of the environmental enrichment provided. The findings of the present study support the use of environmental enrichment for confined cats, either in shelters, laboratories, or households, as it gives cats the opportunity of performing exploratory and foraging behavior without necessarily increasing aggression. A stimulating item that can be shared by all individuals in a stable group, such as a puzzle feeder of appropriate size, can play an important role in promoting positive social interactions among cats and improving their welfare.

a.

Knowles RJ. Correlation of dominance based on agonistic interactions with feeding order in the domestic cat (Felis catus). MS thesis, Department of Anatomy and Radiology, University of Georgia, Athens, Ga, 2002;72.

b.

Souza-Dantas LM, D'almeida JM, Paixao RL. Uso de manejo etológico no controle de agressividade em um gato doméstico: relato de caso (abstr), in Proceedings. 27th Encontro Anu Etol 2008;148.

c.

SPSS, version 17.0 for Windows, SPSS Inc, Chicago, Ill.

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    • Export Citation
  • 21.

    Barry KJ, Crowell-Davis S. Gender differences in the social behavior of the neutered indoor-only domestic cat. Appl Anim Behav Sci 1999; 64: 193211.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 22.

    Martin P, Bateson, P. Measuring behavior. Cambrigde, England: University Press, 1993.

  • 23.

    Ellis SLH, Wells DL. The influence of visual stimulation on the behavior of cats housed in a rescue center. Appl Anim Behav Sci 2008; 113: 166174.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 24.

    Knowles RJ, Curtis TM, Crowell-Davis SL. Correlation of dominance as determined by agonistic interactions with feeding order in cats. Am J Vet Res 2004; 65: 15481556.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 25.

    Dards JL. The behavior of dockyard cats—interactions of adult males. Appl Anim Ethol 1983; 10: 133153.

  • 26.

    Curtis TM, Knowles RJ, Crowell-Davis SL. Influence of familiarity and relatedness on proximity and allogrooming in domestic cats (Felis catus). Am J Vet Res 2003; 64: 11511154.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 27.

    McCobb EC, Patronek GJ, Marder A, et al. Assessment of stress levels among cats in four animal shelters. J Am Vet Med Assoc 2005; 226: 548555.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 28.

    Packard JM. Wolf behavior: reproductive, social and intelligent. In: Mech DL, Boitani L, eds. Wolves: behavior, ecology and conservation. Chicago: University of Chicago Press, 2003, 3565.

    • Search Google Scholar
    • Export Citation
  • 29.

    Natoli E, Vito E. Agonistic behavior, dominance rank and copulatory success in a large multi-male feral cat, Felis catus l., colony in central rome. Anim Behav 1991; 42: 227241.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 30.

    Turner DC, Bateson PPG. The domestic cat: the biology of its behaviour. 2nd ed. New York, Cambridge University Press, 2000.

  • 31.

    Overall KL, Rodan I, Beaver BV, et al. Feline behavior guidelines from the American Association of Feline Practitioners. J Am Vet Med Assoc 2005; 227: 7084.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 32.

    Bateson P, Young M. Separation from the mother and the development of play in cats. Anim Behav 1981; 29: 173180.

  • 33.

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  • 36.

    Feaver J, Mendl M, Bateson P. A method for rating the individual distinctiveness of domestic cats. Anim Behav 1986; 34: 10161025.

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    Casey R. Fear and stress. in: Horwitz DM, Mills DS, Heath S, eds. BSAVA manual of canine and feline behavioral medicine. Quedgeley, Gloucester, England: British Small Animal Veterinary Association, 2002, 144153.

    • Search Google Scholar
    • Export Citation
  • 38.

    Lower SE, Bradshaw JWS. Ontogeny of individuality in the domestic cat in the home environment. Anim Behav 2001; 61: 231237.

  • 39.

    Lee CM, Ryan JJ, Kreiner DS. Personality in domestic cats. Psychol Rep 2007; 100: 2729.

  • 40.

    Turner DC, Feaver J, Mendl M, et al. Variation in domestic cat behavior towards humans—a paternal effect. Anim Behav 1986; 34: 18901892.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 41.

    Bradshaw JWS. The behavior of the domestic cat. Wallingford, Oxfordshire, England: CAB International, 1992.

Appendix

List of agonistic behaviors and behavioral interactions with the puzzle feeder observed in cats communally housed in a shelter.

StareOne cat stops its current activity and gives a fixed gaze at another cat for at least 2 seconds; the staring cat is not easily distracted by other activity around it and has ears erect and forward or erect and rotated sideways
BlockOne catwalks in the direction of another cat while staring at it, making it necessary for the second cat to deviate from its path
FeintMovement by one cat toward another that is immediately followed by a fearful or appeasement signal from the second cat; usually preceded by a stare from the first cat
PounceOne cat leaps at or onto another cat
PawOne cat strikes another cat with a forepaw
ChaseOne cat chases another cat for at least 3 strides
MountOne cat places its sternum against the back of another cat, maintaining its hind limbs on the ground
Supplant bedOne cat takes the place of another cat that was previously there by lying in the same bed
Avoid interactionOne cat withdraws from another cat, avoiding eye contact, not approaching, crouching as the other cat passes by, or moving away from the other cat; the second cat has not displayed any behaviors that would predict the first cat's actions
Retreat from catOne cat backs away from another cat after being stared at, feinted, or blocked.
FlinchOne cat tenses immediately subsequent to an aggressive behavior being directed by another cat; may include blinking and rotating the ears back
Submissive rollSubsequent to an aggressive behavior by another cat, a cat rolls on the ground, exposing its ventrum; the body is tense, with the ears back or flat and the tail swishing or twitching, and the cat may hiss
Retreat from foodOne cat approaches the food trough but retreats as it sees another cat beside the trough, is stared at by a cat that is sitting beside the trough, is attacked by a cat who is sitting beside the trough, or sees a cat eating
Give away foodOne cat that was previously eating leaves immediately upon the arrival of another cat at the food trough shelf, leaves within a maximum of 3 seconds after another cat arrives, or stops eating upon the arrival of the second cat but stays next to the food trough
Move away at food troughOne cat that was previously eating moves at least 60 cm along the shelf and keeps eating upon the arrival of or after being stared at or attacked by a second cat, or a cat arrives at the trough, sees a cat eating, and moves away at least 60 cm before it starts eating
Wait on foodOne cat arrives at the food trough shelf but waits while another cat is eating or is beside the trough; the cat that is waiting alternates looking at or sniffing the food with looking at the cat that is eating
Retreat from bedOne cat attempts to get into a bed that another cat is occupying but ultimately retreats from it
Give away bedOne cat that is occupying a bed leaves within 3 seconds of another cat getting into the bed or staring or attacking it
Wait on bedOne cat waits while another cat uses a bed; the cat that is waiting stares at the bed for at least 3 seconds
Retreat from elevated space*One cat attempts to get onto an elevated space that another cat is occupying but ultimately retreats from it
Give away elevated space*One cat that is occupying an elevated space leaves within 3 seconds after another cat arrives, stares at, or attacks the first cat
Wait on elevated space*One cat waits while another cat uses an elevated space; the cat that is waiting stares at the elevated space for at least 3 seconds
Stare near puzzle feederOne cat that is eating or is beside the puzzle feeder stops its current activity and gives a fixed gaze at another cat for at least 2 seconds; the staring cat is not easily distracted by other activity around it and has ears erect and forward or erect and rotated sideways
Paw near puzzle feederOne cat that is eating from the puzzle feeder or is standing beside it strikes another cat with its forepaw
Bite near puzzle feederOne cat that is eating at the puzzle feeder or standing beside it snaps its teeth at or succeeds in biting another cat
Avoid approaching the puzzle feederOne cat when walking toward the puzzle feeder and looking at it withdraws whenever other cats are using it or walking toward it; it is not possible to tell whether one of the cats is the reason for the avoidance behavior, and no cats at the box display any aggressive behavior to justify the first cat's withdrawal
Flinch near puzzle feederOne cat that is trying to approach or is investigating the puzzle feeder tenses immediately subsequent to aggression by another cat; may include blinking and rotating the ears back
Retreat from puzzle feederOne cat approaches the puzzle feeder but retreats as another cat approaches it or if it is stared at, attacked, feinted, blocked or chased by a cat that is sitting beside or using the puzzle feeder
Approach puzzle feederOne cat walks toward the puzzle feeder until it is close enough to sniff it
Investigate puzzle feederOne cat approaches the puzzle feeder, puts its head in it, and sniffs it or eats
Pull puzzle feederOne cat pulls the puzzle feeder toward itself using one of its front paws
Lie on top of puzzle feederOne cat lies on top of the puzzle feeder

Elevated spaces considered include indoor and outdoor shelves (except the food trough shelf), tables, and a tree trunk.

  • Figure 1—

    Photograph of the puzzle feeder made from a plastic storage box (31 × 20 × 10 cm) and pieces of polyvinylchloride pipe held together by nylon strings.

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    Kessler MR, Turner DC. Socialization and stress in cats (Felis silvestris catus) housed singly and in groups in animal shelters. Anim Welf 1999; 8: 1526.

    • Search Google Scholar
    • Export Citation
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    Barry KJ, Crowell-Davis S. Gender differences in the social behavior of the neutered indoor-only domestic cat. Appl Anim Behav Sci 1999; 64: 193211.

    • Crossref
    • Search Google Scholar
    • Export Citation
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    Martin P, Bateson, P. Measuring behavior. Cambrigde, England: University Press, 1993.

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    Ellis SLH, Wells DL. The influence of visual stimulation on the behavior of cats housed in a rescue center. Appl Anim Behav Sci 2008; 113: 166174.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 24.

    Knowles RJ, Curtis TM, Crowell-Davis SL. Correlation of dominance as determined by agonistic interactions with feeding order in cats. Am J Vet Res 2004; 65: 15481556.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 25.

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  • 26.

    Curtis TM, Knowles RJ, Crowell-Davis SL. Influence of familiarity and relatedness on proximity and allogrooming in domestic cats (Felis catus). Am J Vet Res 2003; 64: 11511154.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 27.

    McCobb EC, Patronek GJ, Marder A, et al. Assessment of stress levels among cats in four animal shelters. J Am Vet Med Assoc 2005; 226: 548555.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 28.

    Packard JM. Wolf behavior: reproductive, social and intelligent. In: Mech DL, Boitani L, eds. Wolves: behavior, ecology and conservation. Chicago: University of Chicago Press, 2003, 3565.

    • Search Google Scholar
    • Export Citation
  • 29.

    Natoli E, Vito E. Agonistic behavior, dominance rank and copulatory success in a large multi-male feral cat, Felis catus l., colony in central rome. Anim Behav 1991; 42: 227241.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 30.

    Turner DC, Bateson PPG. The domestic cat: the biology of its behaviour. 2nd ed. New York, Cambridge University Press, 2000.

  • 31.

    Overall KL, Rodan I, Beaver BV, et al. Feline behavior guidelines from the American Association of Feline Practitioners. J Am Vet Med Assoc 2005; 227: 7084.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 32.

    Bateson P, Young M. Separation from the mother and the development of play in cats. Anim Behav 1981; 29: 173180.

  • 33.

    Nicholas TW, Soltysik SS. Early coping experience and later aversive conditioning in cats. Int J Psychophysiol 1984; 2: 97110.

  • 34.

    Ursin H, Eriksen HR. The cognitive activation theory of stress. Psychoneuroendocrinology 2004; 29: 567592.

  • 35.

    van Doorn GS, Hengeveld GM, Weissing FJ. The evolution of social dominance. II: multi-player models. Behavior 2003; 140: 13331358.

  • 36.

    Feaver J, Mendl M, Bateson P. A method for rating the individual distinctiveness of domestic cats. Anim Behav 1986; 34: 10161025.

  • 37.

    Casey R. Fear and stress. in: Horwitz DM, Mills DS, Heath S, eds. BSAVA manual of canine and feline behavioral medicine. Quedgeley, Gloucester, England: British Small Animal Veterinary Association, 2002, 144153.

    • Search Google Scholar
    • Export Citation
  • 38.

    Lower SE, Bradshaw JWS. Ontogeny of individuality in the domestic cat in the home environment. Anim Behav 2001; 61: 231237.

  • 39.

    Lee CM, Ryan JJ, Kreiner DS. Personality in domestic cats. Psychol Rep 2007; 100: 2729.

  • 40.

    Turner DC, Feaver J, Mendl M, et al. Variation in domestic cat behavior towards humans—a paternal effect. Anim Behav 1986; 34: 18901892.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 41.

    Bradshaw JWS. The behavior of the domestic cat. Wallingford, Oxfordshire, England: CAB International, 1992.

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