FULL PAPER Ethology
A Comparison of the Behavioral Profiles of Purebred Dogs in Japan to Profiles of those in the United States and the United Kingdom
Yukari TAKEUCHI1) and Yuji MORI1)
1)Laboratory of Veterinary Ethology, The University of Tokyo, 1–1–1 Yayoi, Bunkyo-ku, Tokyo 113–8657 Japan
(Received 8 December 2005/Accepted 28 March 2006)
ABSTRACT. To clarify the behavioral profiles of 56 pure breeds of dogs in Japan, 96 small-animal veterinarians participated in a question- naire survey using the same criteria as in preceding studies conducted in the United States and the United Kingdom. We found significant differences among breeds in all behavioral traits examined. In addition, gender differences were revealed in terms of aggression to dogs, territorial defense, excitability, general activity, dominance over owner, destructiveness, watchdog barking, and snapping at children, which were all rated higher in males than females, whereas obedience training and housebreaking ease were rated higher in females. No gender differences were evident in playfulness, excessive barking, or affection demand. Using factor analyses, “aggressiveness”, “reac- tivity”, and “trainability” were determined to be consistent with results found in the US and UK surveys. On the basis of these factor scores, seven groups of breeds were determined by cluster analysis to compare to the US survey; 22 of the 38 breeds common with the US survey were categorized into the same groups as those in that survey. The results demonstrated differences in canine behavioral pre- disposition among breeds and between genders. The similarity in the results between our study and previous surveys, which involved distinct geographical locales, suggests that the genetic basis of breed-specific temperamental traits is manifested irrespective of the cul- tural or regional identities of the owners. KEY WORDS: behavioral trait, breed difference, canine, gender difference, questionnaire survey. J. Vet. Med. Sci. 68(8): 789–796, 2006
The dog is one of the most heavily domesticated animals compared to European and North American owners, and has been subjected to intensive artificial selection to because most dogs in Japan were traditionally held outside meet various utilitarian demands, such as hunting, guarding, as watchdogs until recently and are still used as watchdogs and herding. Some breeds are therefore genetically special- in rural areas. While experts such as behaviorists and train- ized to fulfill specific physical and/or instinctive roles. Con- ers have been emphasizing the importance of understanding sequently, the behavioral profiles of purebred dogs have the behavioral profile of a purebred dog before becoming a become highly diversified. Nearly half a century ago, a dog owner, many prospective owners tend to select dogs at large-scale investigation was conducted in an attempt to pet shops based on features such as body size and color. evaluate the heritability of specific behavioral traits in vari- Moreover, in Japan, sales booms of particular breeds have ous canine breeds by analyzing those behavioral traits in occurred in the past, and it is speculated that these booms dogs raised in the same environment over several genera- have resulted in various behavioral problems after the pas- tions in the Jackson Laboratory [18]. Other attempts to sage of a fad simply because of haphazard breeding pro- reveal breed differences in behavioral traits were performed grams and inadequate preweaning. It appears that these at the University of California, Davis [6–8]. A similar sur- sales booms are caused not only by a lack of knowledge of vey was carried out in the United Kingdom about 10 years the historical background of purebred dogs, but also by the later to compare the behavioral traits of purebred dogs there absence of information on the behavioral profiles of pure- to those in the United States [2, 3]. In the UC-Davis study, bred dogs in Japan, which has been said to be derived from the authors surveyed obedience judges and veterinarians relatively small numbers of ancestral individuals for each about their opinions on 13 behavioral characteristics of 56 breed and selective breeding in accordance with Japanese representative breeds and found significant breed differ- custom. ences in all traits [8]. Taking the history of domestication This study was conducted to gather information on the into account, these breed differences in behavioral traits are behavioral profiles of purebred dogs in Japan, which could derived in part from genetic factors, although environmental be important for future research on behavior genetics and and experiential factors are also involved. Based on this could also provide reliable information to prospective dog premise, we attempted to determine the genetic factors owners. By replicating the questionnaire survey conducted responsible for these behavioral traits [9, 11, 13–16, 19, 20]. in both the United States [7, 8] and the United Kingdom [3], The number of dogs in Japan has increased from 9 million we could directly compare our results to these earlier sur- in 1994 to 11 million in 2003, and more than half are esti- veys. mated to be purebred (Pet food manufactures association, Japan; http://www.jppfma.org/index.html, in Japanese). MATERIALS AND METHODS However, it is generally acknowledged that the Japanese know less about how to appropriately interact with dogs A questionnaire survey was taken by 96 veterinary prac- 790 Y. TAKEUCHI AND Y. MORI titioners in Japan according to the procedure described in ted), and also to indicate whether males or females were previous US and UK surveys [3, 7, 8]. Forty-eight veteri- more likely to exhibit that behavior. Basically, each breed narians were recruited from the mailing list of the “Japanese was evaluated for behavioral traits by 12 veterinarians. veterinary society for the study of animal behavior; http:// However, because they were allowed to skip the breed with www.vm.a.u-tokyo.ac.jp/koudou/vbhHP/, in Japanese”, and which they considered unfamiliar, the actual number of vet- 48 additional veterinarians were enlisted by core members erinarians who evaluated each breed varied between 5 and of this society. Of the 96 respondents, 58 (60%) were male. 12 depending on breeds and behavioral traits (10–12 veteri- The participants resided across the country but were mainly narians for 80% of breeds in this study). The methods for located in the Tokyo and Osaka areas. On average, they had data processing were in accordance with the previous 14.5 years of clinical experience (range: 1–50 years). All reports [3, 7, 8]. respondents were contacted via fax or e-mail to which a All statistics, including factor analysis using the principal questionnaire, a guide for the survey, and a detailed descrip- factor method with varimax rotation and a cluster analysis tion of each rated behavioral trait were attached. The 56 with the method of k-means, were conducted with Stat- breeds were selected for the survey based on the rankings of graphics Centurion XV (http://www.statgraphics.com/). their average numbers registered during the period 1999– Cluster analysis was performed based on the scores of fac- 2003. The information was obtained from the web site of tors 1, 2, and 3 obtained in this study, which corresponded to the Japan Kennel Club, Inc. (http://www.jkc.or.jp/jkc_info/ factors 2, 1, and 3, respectively, of the US survey. The Jap- index.html, in Japanese). The 56 breeds selected in this anese clusters were produced by incorporating one breed as study are presented in Table 5. a “seed” for each US cluster for comparison to the structure The questionnaire referred to 13 criteria as in the previous of clusters in the US survey. The seed breeds (shown in studies [3, 7, 8], i.e., excitability, general activity, snapping Table 5 with bold and italic font) were selected as the repre- at children, excessive barking, playfulness, obedience train- sentative breeds in Japan. ing, watchdog barking, aggression to dogs, dominance over owner, territorial defense, affection demand, destructive- RESULTS ness, and housebreaking ease. The respondents were asked to rank the seven breeds from the lowest to the highest level Breed differences in behavioral traits: Behavioral traits of expression for each behavior (same ranks were permit- ranked in order of decreasing reliability in differentiating
Table 1. Behavioral traits ranked in order of decreasing reliability in differentiating between dog breeds, as indicated by magnitude of the F-ratio, and the five highest and five lowest breeds for each behavioral trait in Japanese survey
Behavioral trait F-ratio P-value Highest (plane) and lowest (italic) 5 breeds of each behavioral trait (each averaged score was shown in parentheses)
Playfulness 6.97 <.0001 Labrador Retriever (6.5), Golden Retriever (6.3), Border Collie (6.2), Flat-Coated Retriever (5.9),Pembroke Welsh Corgi (5.8), Great Dane (1.8), Saint Bernard (1.7), Great Pyrenees (1.7), Borzoi (1.6), Akita (1.5) Excessive barking 6.78 <.0001 Kaninchen Dachshund (6.4), Maltese (6.3), Pomeranian (6.2), Yorkshire Terrier (6.1), Beagle (6.0) Afghan Hound (2.3), Saint Bernard (1.8), Newfoundland (1.8), Borzoi (1.5), Bulldog (1.3) Affection demand 6.17 <.0001 Miniature Dachshund (6.2), Labrador Retriever (6.2), Toy Poodle (6.1), Cavalier King Charles Spaniel (5.9), Maltese (5.7), German Shepherd Dog (2.0), Borzoi (1.9), Great Dane (1.8), Saint Bernard (1.8), Akita (1.6) General activity 5.81 <.0001 Border Collie (6.8), Jack Russell Terrier (5.8), Miniature Pinscher (5.8), Wire Fox Terrier (5.6), Shetland Sheepdog (5.5) Chin (1.9), Great Pyrenees (1.6), Saint Bernard (1.5), Bulldog (1.4), Basset Hound (1.3) Aggression to dogs 5.54 <.0001 Pembroke Welsh Corgi (6.5), Miniature Pinscher (6.4), Shiba Inu (6.3), Cairn Terrier (5.9), Akita (5.9), Pekingese (2.3), Saint Bernard (2.3), Cavalier King Charles Spaniel (2.3), Italian Greyhound (2.2), Flat-Coated Retriever (2.0) Watchdog barking 4.96 <.0001 Miniature Pinscher (6.3), Shiba Inu (6.2), Shetland Sheepdog (6.1), German Shepherd Dog (5.8), Doberman Pinscher (5.6), Saint Bernard (2.1), Great Dane (2.0), Newfoundland (1.9), Bulldog (1.8), Basset Hound (1.7) Territorial defense 4.76 <.0001 Miniature Pinscher (6.4), Shiba Inu (6.2), German Shepherd Dog (6.0), Doberman Pinscher (5.9), Pembroke Welsh Corgi (5.8), Labrador Retriever (2.2), Bichon Frise (2.0), Italian Greyhound (2.0), Golden Retriever (2.0), Chin (1.5) Snapping at children 4.49 <.0001 Miniature Pinscher (6.6), Chihuahua (6.4), Pembroke Welsh Corgi (6.3), Cairn Terrier (5.7), Shiba Inu (5.6) Flat-Coated Retriever (2.3), Labrador Retriever (2.2), Borzoi (2.2), Newfoundland (2.0), Saint Bernard (1.7) Excitability 4.44 <.0001 Beagle (5.8), Kaninchen Dachshund (5.8), Jack Russell Terrier (5.7), Miniature Pinscher (5.6), Chihuahua (5.4) Chin (2.1), Borzoi (2.0), Bulldog (1.7), Saint Bernard (1.6), Basset Hound (1.5) Obedience training 3.24 <.0001 Labrador Retriever (6.5), Doberman Pinscher (6.3), Golden Retriever (6.0), Flat-Coated Retriever (5.8), German Shepherd Dog (5.7), Pekingese (2.5), Miniature Pinscher (2.5), Chihuahua (2.4), Basset Hound (2.4), Miniature Bull Terrier (1.9) Dominance over owner 2.99 <.0001 Afghan Hound (6.4), Pembroke Welsh Corgi (6.2), Wire Fox Terrier (5.8), Miniature Bull Terrier (5.8), Miniature Pinscher (5.8), Labrador Retriever (2.6), Golden Retriever (2.5), Flat-Coated Retriever (2.3), Bichon Frise (2.3), Sain Bernard (2.1) Destructiveness 2.94 <.0001 Pembroke Welsh Corgi (6.0), Beagle (5.8), Cairn Terrier (5.7), Kaninchen Dachshund (5.5), Jack Russell Terrier (5.5) Bulldog (2.3), Borzoi (2.2), Pekingese (2.1), Chin (2.0), Italian Greyhound (1.8) Housebreaking ease 1.43 0.0293 Golden Retriever (6.3), Flat-Coated Retriever (5.5), Borzoi (5.3), Great Dane (5.0), Standard Dachshund (5.0) West Highland White Terrier (3.0), Old English Sheepdog (3.0), Bernese Mountain Dog (2.9), Miniature Bull Terrier (2.8), Bulldog (2.3) BEHAVIORAL PROFILES OF PUREBRED DOGS IN JAPAN 791
Table 2. Overlapping breeds for each behavioral trait between Japanese and US surveys (from ref. 6 pp. 34-59.) comparing extreme 11 breeds
Table 3. Factor loading(s) of each behavioral characteristic in Japanese survey Behavioral characteristic Factor 1 Factor 2 Factor 3 Aggression to dogs 0.828 Snapping at children 0.743 Territorial defense 0.774 Dominance over owner 0.726 Watchdog barking 0.712 Playfulness 0.860 Affection demand 0.768 General activity 0.692 Excitability 0.511 0.668 Excessive barking 0.536 0.594 Destructiveness 0.531 Housebreaking ease 0.814 Obedience training 0.717
one of the three factors (the absolute value of factor loading was more than 0.4), as shown in Table 3. Factor 1, “aggres- siveness”, accounted for 37.7% of the variance and was associated with aggression to dogs, snapping at children, territorial defense, dominance over owner, and watchdog barking. Factor 2, “reactivity”, accounted for 17.1% and was associated with playfulness, affection demand, general activity, and destructiveness. Excitability and excessive barking were nearly equally weighted on both factors 1 and 2. Factor 3, “trainability”, was associated with housebreak- ing ease and obedience training. A comparison of the factor structures among the Japa- nese, US, and UK surveys revealed that similar factors Fig. 1. Gender analysis of 13 behavioral traits. The quantitative belonging to mostly common behavioral traits were rating was determined by “(the number of veterinarians rating extracted among these three surveys with a few exceptions males higher— those rating females higher)/total number of vet- erinarians × 100”. The black columns indicate that males were such as factor 4 (investigation) in the US survey and factor rated significantly higher, gray columns denote that females 3 (immaturity) in the UK survey, as shown in Table 4. were rated significantly higher, and white columns represent Cluster analysis: According to the cluster analysis using traits for which a significant number of veterinarians considered the k-means method on each of the three factors, seven clus- no gender difference. ters of breeds were generated, as shown in Table 5. Twenty- two of 38 breeds in common with the US survey were cate- dance rate was 49.3%, with a range between 26.7 (house- gorized into the same groups as those of that survey, and 14 breaking ease) and 68.8 (obedience training). of 35 breeds in common with the UK survey were catego- Gender differences in behavioral traits: The gender anal- rized into the same groups as those of that survey. yses of the 13 behavioral traits are shown in Fig. 1. Veteri- narians found no gender differences in some behavioral DISCUSSION traits such as playfulness, excessive barking, and affection demand (χ2 test for goodness of fit, p<0.0005, except for In this study, we observed significant breed differences in playfulness p<0.05, χ2 =4.17 to 35.04, df=1). Regarding the all behavioral traits examined, which were mostly in accor- other behavioral traits, significantly more veterinarians dance with those reported in preceding studies in the United rated males higher than females in aggression to dogs, terri- States [8] and the United Kingdom [3]. Between the US and torial defense, excitability, general activity, dominance over UK surveys, obedience training was the only inconsistency owner, destructiveness, snapping at children, and watchdog regarding breed differences, and the UK authors speculated barking (χ2 test for goodness of fit, p<0.0001, χ2 =28.45 to that the working potential of dogs was regarded as more 85.00, df=1), whereas females were ranked higher in obedi- important in the United States, whereas their role as com- ence training and housebreaking ease (χ2 test for goodness panions may have been more valued in the United Kingdom of fit, p<0.0001, χ2 =21.36, 27.94, respectively, df=1). for some guarding and watchdog breeds. This may be true Factor analysis: The factor analysis resulted in the for the situation in Japan as well, since many native Japa- extraction of three main factors with eigenvalues greater nese dogs such as the Shiba Inu and Akita have been kept as than 1.0. The three factors together accounted for 63.3% of watchdogs and guarding dogs. A similar survey conducted the common variance, and each item belonged to more than in Japan, which involved 54 veterinarians who evaluated 19 BEHAVIORAL PROFILES OF PUREBRED DOGS IN JAPAN 793
Table 4. Comparison of factor structure among Japanese, US (Table 1 from ref. 7) and UK surveys (Table 1 from ref. 3)
Table 5. Seeded cluster analysis of factor scores for Japanese breeds to US breeds
H.-S., Ha, J.-H., Kitagawa, H., Takeuchi, Y., Mori, Y., 19. Takeuchi, Y., Hashizume, C., Chon, E. M. H., Momozawa, Y., Iwasaki, T., Morita, M. and Ota, K. 2005. Novel polymorphism Masuda, K., Kikusui, T. and Mori, Y. 2005. Canine tyrosine of the canine dopamine receptor D4 gene intron II region. hydroxylase gene (TH) and dopamine beta-hydroxylase gene Anim. Sci. J. 76: 81–86. (DBH): their sequences, genetic polymorphisms, and diversi- 16. Ogata, N., Hashizume, C., Momozawa, Y., Masuda, K., ties among five different dog breeds. J. Vet. Med. Sci. 67: 861– Kikusui, T., Takeuchi, Y. and Mori, Y. 2006. Polymorphisms 867. in the canine glutamate transporter-1 gene: identification and 20. Takeuchi, Y. and Houpt, K. A., 2003. Behavior genetics. pp. variation among five dog breeds. J. Vet. Med. Sci. 68: 157–159. 345–363. In: Veterinary Clinics of North America. Small Ani- (Published erratum appears in J. Vet. Med. Sci. 68(7), last page). mal Practice. -Update on Clinical Veterinary Behavior-, vol. 33 17. Parker, H. G., Kim, L. V., Sutter, N. B., Carlson, S., Lorentzen, (Houpt, K.A. and Virga, V. eds.), The W.B. Saunders, Phila- T. D., Malek, T. B., Johnson, G. S., DeFrance, H. B., delphia. Ostrander, E. A. and Kruglyak, L. 2004. Genetic structure of 21. Tanabe, Y., Ogata, M., Kamiya, F. and Okabayashi, H. 1999. the purebred domestic dog. Science 304: 1160–1164. Breed difference in behavioral profiles of dog: Quantitative 18. Scott, J. P. and Fuller, J. L., 1965. Genetics and the Social analyses by veterinarians in Japan. Jpn J. Hum. Anim. Relat. 6: Behavior of the Dog. The Classic Study, The University of 92–98 (in Japanese). Chicago Press.