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Showing posts with label genotypic variation. Show all posts
Showing posts with label genotypic variation. Show all posts

Sunday, October 28, 2012

Breeding dogs for beauty and behaviour: Why scientists need to do more to develop valid and reliable behaviour assessments for dogs kept as companions




Effects of Breeding for Looks Rather than Behavior



Tammie King, Linda C. Marston, Pauleen C. Bennett
Breeding dogs for beauty and behaviour: Why scientists need to do more to develop valid and reliable behaviour assessments for dogs kept as companions
Applied Animal Behaviour Science, Volume 137, Issues 1–2, February 2012, Pages 1–12

Abstract

In the past, dogs were bred to perform specific utilitarian roles. Nowadays, the dog's most common role is that of human companion. Our world has changed dramatically since the first dog breeds were developed, yet many of these existing breeds remain popular as companions. While dogs kept as companions can provide a range of benefits to humans, in some cases the relationship between dog and human can be tenuous or even dangerous. Many dogs exhibit behaviours their owners consider undesirable and these dogs may cause disruption and injury to humans and other animals. As a consequence, many are relinquished to shelters. It is proposed that some of this unsuitable behaviour may be the result of inappropriate dog-owner matching, made more likely by the general change in the role of dogs, from working dog to companion animal, coupled with a strong tendency for modern owners and breeders to select dogs primarily on the basis of morphological, rather than behavioural, characteristics. This paper highlights how roles for dogs have changed and the importance of taking physical health and behaviour, as well as perceived beauty, into consideration when breeding and selecting dogs as companions. The measurement of behaviour and limitations of existing canine behaviour assessments are discussed. Finally, it is suggested that scientific development of accurate behavioural assessments, able to identify desirable canine behavioural traits, would provide invaluable tools for a range of dog-related organisations.

Understanding the genetic basis of canine anxiety: phenotyping dogs for behavioral, neurochemical, and genetic assessment


Dogs and Separation Anxiety


Karen L. Overall, MA, VMD, PhD, Steven P. Hamilton, MD, PhD, Melanie Lee Chang, PhD
Understanding the genetic basis of canine anxiety: phenotyping dogs for behavioral, neurochemical, and genetic assessment
Journal of Veterinary Behavior: Clinical Applications and Research, Volume 1, Issue 3, November–December 2006, Pages 124–141

Introduction: the Canine Behavioral Genetics Project (CBGP)

Behavioral problems account for the death, relinquishment, or the end of breeding careers of more dogs than does any other set of problems ( [Miller et al 1996], [Patronek et al 1996], [Salman et al 1998] and [Salman et al 2000]; Scarlett et al., 1999; [Shore et al 2003], [Mondelli et al 2004] and [Shore 2005]). Whereas many behavioral complaints involve management-related issues or dog-human temperament mismatches, the behavioral concerns that are most interesting to scientists and breeders alike are those with familial patterns.
A number of conditions have been identified as running in family lines of a number of breeds including, but not restricted to, generalized anxiety/fear, noise phobia, impulse/control aggression, conspecific aggression, predatory aggression, and obsessive-compulsive disorder ( [Overall 1994], [Overall and Dunham 2002] and [Overall 2005]). Most of these conditions appear sometime between one and two years of age, the social maturity period, during which neural systems are undergoing extensive developmental changes. The potential benefit of genetic counseling is clear, and the potential to make dogs “safer” and happier is substantial. Understanding the genetic bases of behavioral problems will lead to more humane treatment of dogs, fewer public health risks, an improved public perception of dogs as pets, and a considerable lessening in the recycled pet problem. Additionally, elucidation of the biological systems underlying pathological behavior will heighten our general understanding of the underlying molecular biology of behavior, allowing the dog to contribute to this rapidly evolving field.
Over 50 breeds across all seven AKC groups have family lines in which “fear/shyness/nervousness/panic/anxiety” is a major breeder-reported concern (Overall, unpublished). Within these breeds, this “trait” often follows familial lines, suggesting a heritable basis. This pattern has been noted for many physical conditions in dogs ( [Sutter et al 2004] and [Lark et al 2006]), but little emphasis has been placed on behavioral conditions because of the difficulty in defining a clear phenotype. Although recognition of other genetically mediated conditions is often straightforward, based on easily observable clinical phenomena that are defined by consensus (e.g., cancer, retinopathies, narcolepsy), assignment of behavioral phenotypes can be open to misclassification or misinterpretation ( [Overall 2005] and [Overall and Burghardt 2006]).
The broad goal of the CBGP is to explore the genetic background of anxiety-related behavioral problems in dogs. To do so, we must: (1) solicit the participation of owners of candidate dogs possibly affected by anxiety-related behavioral problems; (2) identify affected and unaffected dogs, using the necessary and specific diagnostic criteria to make a diagnosis of the condition; (3) confirm the presence of the relevant diagnosis in these dogs and if possible in their family lines, using reliable, repeatable, and validated behavioral measures involving questionnaires and videos; and (4) obtain DNA samples for genetic linkage and association analyses, along with the relevant pedigrees. In this article, we discuss the distinction between diagnosis and phenotype, and we describe our protocol for assessing behavioral phenotypes in dogs, addressing the second and third aspects of our project just discussed.