Genetics of Canine Behavior

Houpt K.A. : Genetics of Canine Behavior. Acta Vet. Brno 2007, 76: 431-444. Canine behavioral genetics is a rapidly moving area of research. In this review, breed differences in behavior are emphasized. Dog professionals’ opinions of the various breeds on many behavior traits reveal factors such as reactivity, aggression, ease of training and immaturity. Heritability of various behaviors – hunting ability, playfulness, and aggression to people and other dogs – has been calculated. The neurotransmitters believed to be involved in aggression are discussed. The gene for aggression remains elusive, but identifi cation of single nucleotide polymorphisms associated with breed-specifi c behavior traits are leading us in the right direction. The unique syndrome of aggression found in English Springer Spaniels may be a model for detecting the gene involved. Dog aggression, heritability, temperament Behavior is a result of nature (genetics) and nurture (learning or experience). We shall review the history of canine behavioral genetics and explore the latest fi ndings. The publication of the canine genome allows us to make some inferences (Kirkness et al. 2003). Foxes One of the most thorough studies of canid behavioral genetics deals with foxes, not dogs. Selection for a tame and for an aggressive strain of silver foxes over 30 years by Dmitry Belyaev and Lyudmila Trut resulted in large differences in behavior and in morphology (Trut et al. 2006). The tame foxes were more likely to have spots, fl oppy ears, and curly tails. Tame and aggressive foxes have been bred and there are 300 backcross offspring (Trut et al. 2006). These three generation pedigrees are allowing Anna Kukekova and her colleagues at Cornell University to use linkage analysis to fi nd the gene for tameness and for aggression. The karyotypic differences between fox and dog represent 26 chromosomal fusion and four fi ssion events, so that anything learned about foxes will apply to dogs as well (Kukekova et al. 2006). Breed Differences in Behavior There are several approaches to classifying behaviors. We shall review four of these: breed differences in behavioral neoteny; breed differences in social signaling; breed differences in prevalence of behavior problems; and opinions of dog experts on behavioral characteristics of various breeds. There are obvious physical differences among dog breeds and, although behavior does not vary as widely as size and skeletal features, there are marked breed differences in behavior. In fact, many lectures on canine genetics begin with a statement about genetic differences in behavior, but few of the genes are known. Dr. Yukari Takeuchi and her colleagues at Tokyo University have made the most progress and we will review their fi ndings here. ACTA VET. BRNO 2007, 76: 431-444; doi:10.2754/avb200776030431 Address for correspondence: K.A. Houpt Diplomate, American College of Veterinary Behaviorists Animal Behavior Clinic, Department of Clinical Sciences College of Veterinary Medicine Cornell University Ithaca, NY 14853-6401, USA Phone: (607) 253-3450 Fax: (607) 253-3846 Email: kah3@cornell.edu http://www.vfu. cz/acta-vet/actavet.htm