DOCSLIB.ORG

Absolute Brain Size Predicts Dog Breed Differences in Executive Function

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Absolute Brain Size Predicts Dog Breed Differences in Executive Function Absolute Brain Size Predicts Dog Breed Differences in Executive Function Daniel J. Horschler1,*, Brian Hare2,3, Josep Call4,5, Juliane Kaminski6, Ádám Miklósi7,8, & Evan L. MacLean1 Supplementary Material 1School of Anthropology, University of Arizona, Tucson, AZ, 85719, United States 2Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, United States 3Center for Cognitive Neuroscience, Duke University, Durham, NC, 27708, United States 4Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany 5School of Psychology and Neuroscience, University of St Andrews, St Andrews, United Kingdom 6Department of Psychology, University of Portsmouth, Portsmouth, United Kingdom 7Department of Ethology, Eötvös Loránd University, Budapest, Hungary 8MTA-ELTE Comparative Ethology Research Group, Budapest, Hungary *Correspondence - Email: [email protected]; Phone: 520-621-2646 Method Details Cognitive Data. Cognitive data were compiled from the Dognition.com database. Dognition.com is a citizen science website that provides dog owners with instructions for completing cognitive experiments with pet dogs in their homes. Participants receive written and video instructions for the behavioral protocols, and electronically submit data on their dog’s responses as activities are completed. We included data from ten cognitive tasks in our analyses: Yawning, Eye Contact, Arm Pointing, Foot Pointing, Cunning, Memory vs. Pointing, Memory vs. Smell, Delayed Memory, Inferential Reasoning, and Physical Reasoning. For detailed protocols of each task, see Task Details. We analyzed all subjects from a dataset originally including 18,610 dogs, with the majority of these dogs having completed multiple tasks. To ensure that our sample included only adult dogs, we removed all data from dogs who were 1 year or younger at the time of testing (n = 2,307). Because our analyses focused on breed-average performance, we eliminated data from dogs that were identified as mixed breeds, or for whom the breed identity was not known (n = 5,311; both measures determined by owner report). We also eliminated data from a small subset of poodles with reported body weights intermediate to miniature and standard morphs (n = 22, see Morphological Data). Lastly, to ensure representative samples across breeds we removed data from breeds represented by less than 20 individuals (on a task-wise basis), as well as for breeds which lacked body weight or genetic data (n = 3,573 individuals) from the primary sources these data were compiled from (see below). The final dataset we analyzed included 7,397 dogs. Demographic data for each breed included in our analyses is shown in Supplementary Table 1. Data Collection Process. All text in this section and in the following Task Details section was directly adapted from Stewart et al. (2015). All participants received instructions recommending cognitive tasks be conducted at home in a familiar room reasonably free of distractions. Participants were encouraged to take breaks whenever the dog lost motivation, and were repeatedly reminded not to intentionally influence their dog’s choices, although experimental evidence suggests that the effect of unconscious cuing on dogs during cognitive experiments may not be as ubiquitous as has often been suggested (Hauser, Comins, Pytka, Cahill, & Velez-Calderon, 2011; Pongrácz, Miklósi, Bálint, & Hegedüs, 2013; Schmidjell, Range, Huber, & Virányi, 2012). Regardless, instructions were worded to frequently remind participants that there “are no correct answers” and to let their dog choose freely. For each task, participants watched a how-to video that detailed the experimental setup, procedural protocol, and the set of possible responses from their dog that they would need to live code. Written instructions and a Frequently Asked Questions (FAQ) section were also provided, and a link to the FAQ was available at all times in case questions arose during testing. Participants were not able to advance through tasks or trials out of order, to help ensure that participants correctly followed all steps, and repeated each trial the correct number of times. Once all of the steps were complete for each trial, participants were asked to code their dog’s behavior. The majority of decisions involved either stopping a timer or indicating which of two locations the dog approached first. Participants were instructed to work with a partner unless their dog was able to sit and stay on their own. Video and written instructions emphasized the importance of staring directly ahead after releasing the dog, and of releasing the dog without nudging, pushing, or leading the dog in one direction or the other. In the instructional video, the dog was positioned directly across from the experimenter, approximately 1.8m away. Three post-it notes were placed on a line perpendicular to the dog and the experimenter. The center post-it was placed 0.6m directly in front of the experimenter, while the other two were placed 0.9m on either side of the center post-it. Once participants completed this set up, they advanced to step-by-step instructions for each trial. Task Details. The vast majority of dogs were tested using the following task order: Yawning, Eye Contact, Arm Pointing, Foot Pointing, Cunning, Memory vs. Pointing, Memory vs. Smell, Delayed Memory, Inferential Reasoning, and Physical Reasoning. Non-differential rewarding (in which any choice was rewarded) was used in Arm Pointing, Foot Pointing, and Cunning, while differential rewarding was used in Memory vs. Pointing, Memory vs. Smell, Delayed Memory, Inferential Reasoning, and Physical Reasoning. Task Details: Yawning. The Yawning task procedure was based on Joly-Mascheroni et al. (2008). Participants watched a video of instructions that included examples of dogs yawning. Participants were instructed to sit on the floor with the dog, but not to touch or interact with the dog at any point during the yawning conditions. In the control condition, the participant was prompted to say the word “yellow” every 5 seconds for 30 seconds. In the experimental condition, the participant was instructed to yawn clearly and audibly every 5 seconds for 30 seconds. Once this 30-second period ended, a 2-minute timer started. During the 30-second manipulation and the 2 minutes that followed, the participants were instructed to observe if the dog yawned. They were prompted to code whether the dog yawned after each trial (they were not asked for a frequency). There was only one trial of each condition, and all subjects received the control condition first. Task Details: Eye Contact. Procedurally, the Eye Contact task was based on Nagasawa et al. (2009). Participants first conducted a warm-up condition, in which the participant was instructed to stand facing their dog with the dog standing or sitting ~1.8 meters away. The participant was then prompted to call the dog’s name, show the dog a small treat, and place that treat directly beneath their eye and to start the 10-second timer. Once time elapsed, the participant was prompted to give the dog the treat. No coding was required and the warm-up was repeated three times. The experimental condition was the same as the warm-up except that the participant was instructed to stop the timer once the dog broke eye contact for more than two seconds. If the dog never broke eye contact, the trial ended after 90 seconds. Three trials of this condition were conducted. Task Details: Arm Pointing and Foot Pointing. The Arm Pointing task was based on Gácsi et al. (2009) while the Foot Pointing task was based on Lakatos et al. (2009). In the pointing warm- up, the dog was introduced to the two potential locations to find a treat. The participant was instructed to stand ~1.8m away from the dog, call the dog’s name, show the dog a treat, and place the treat down on the ground at arm’s length to either the left or right (~1.2m apart). The instructions indicated which side to place the treat on in each trial. The treat location was counterbalanced across trials and participants never placed a treat on the same side on two consecutive trials. Once the participant had placed the treat, they were instructed to release the dog while giving a release command. After each trial, the participant was asked to record if the dog retrieved the treat. There were six trials in this warm-up. The Arm Pointing and Foot Pointing conditions were identical to the warm-up except that two identical food treats were placed at arm’s length on either side. Participants were instructed which location they were to gesture toward and to allow the dog to retrieve both treats while recording which location the dog approached first. A first approach was illustrated in the video and was defined as crossing the plane created by the post-it notes on the left or right. In the Arm Pointing condition, participants were to point by extending their arm, hand, and index finger toward one location while standing equidistant between the two locations. In the Foot Pointing condition, participants were instructed to take one step toward one location while extending their leg and food in the direction of the other location. In both experimental conditions, gaze and gesture was to be directed at the location being indicated until the dog made their choice. Six trials were conducted in each condition. Task Details: Cunning. The Cunning (Other’s Visual Cues) task was procedurally based on Call et al. (2003). In the baseline watching condition, the dog was positioned ~1.8m from the participant. The participant was then instructed to say the dog’s name and “No” or “Leave it” twice, clearly and loudly, while placing a treat in front of them on the ground. Once the participant stood back up, they activated the countdown timer, which they only stopped when the dog approached and ate the forbidden food.
Load more

Recommended publications
  • Associations Between Domestic-Dog Morphology and Behaviour Scores in the Dog Mentality Assessment
    Associations between domestic-dog morphology and behaviour scores in the Dog Mentality Assessment Stone, Holly R.; McGreevy, Paul D.; Starling, Melissa J.; Forkman, Björn Published in: P L o S One DOI: 10.1371/journal.pone.0149403 Publication date: 2016 Document version Publisher's PDF, also known as Version of record Document license: Other Citation for published version (APA): Stone, H. R., McGreevy, P. D., Starling, M. J., & Forkman, B. (2016). Associations between domestic-dog morphology and behaviour scores in the Dog Mentality Assessment. P L o S One, 11(2), [e0149403]. https://doi.org/10.1371/journal.pone.0149403 Download date: 24. Sep. 2021 RESEARCH ARTICLE Associations between Domestic-Dog Morphology and Behaviour Scores in the Dog Mentality Assessment Holly R. Stone1*, Paul D. McGreevy1, Melissa J. Starling1, Bjorn Forkman2 1 Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales, 2006, Australia, 2 University of Copenhagen, Copenhagen, Denmark * [email protected] Abstract The domestic dog shows a wide range of morphologies, that humans have selected for in the process of creating unique breeds. Recent studies have revealed correlations between changes in morphology and behaviour as reported by owners. For example, as height and OPEN ACCESS weight decrease, many undesirable behaviours (non-social fear, hyperactivity and attention seeking) become more apparent. The current study aimed to explore more of these correla- Citation: Stone HR, McGreevy PD, Starling MJ, Forkman B (2016) Associations between Domestic- tions, but this time used reports from trained observers. Phenotypic measurements were Dog Morphology and Behaviour Scores in the Dog recorded from a range of common dog breeds (n = 45) and included cephalic index (CI: the Mentality Assessment.
    [Show full text]
  • Les Hypertypes Chez Les Chiens Et Chats De Race : Etude Bibliographique Et Observationnelle
    VETAGRO SUP CAMPUS VETERINAIRE DE LYON Année 2017 - Thèse n° 019 LES HYPERTYPES CHEZ LES CHIENS ET CHATS DE RACE : ETUDE BIBLIOGRAPHIQUE ET OBSERVATIONNELLE THESE Présentée à l’UNIVERSITE CLAUDE-BERNARD - LYON I (Médecine - Pharmacie) et soutenue publiquement le 1er septembre 2017 pour obtenir le grade de Docteur Vétérinaire par MICHEL Morgane Née le 22 mai 1991 à Le Creusot VETAGRO SUP CAMPUS VETERINAIRE DE LYON Année 2017 - Thèse n° 019 LES HYPERTYPES CHEZ LES CHIENS ET CHATS DE RACE : ETUDE BIBLIOGRAPHIQUE ET OBSERVATIONNELLE THESE Présentée à l’UNIVERSITE CLAUDE-BERNARD - LYON I (Médecine - Pharmacie) et soutenue publiquement le 1er septembre 2017 pour obtenir le grade de Docteur Vétérinaire par MICHEL Morgane Née le 22 mai 1991 à Le Creusot 2 Liste de Enseignants du Campus Vétérinaire de Lyon MAJ: 13/04/2017 Civilité Nom Prénom Département Grade Mme ABITBOL Marie DEPT-BASIC-SCIENCES Maître de conférences M. ALVES-DE-OLIVEIRA Laurent DEPT-BASIC-SCIENCES Maître de conférences Mme ARCANGIOLI Marie-Anne DEPT-ELEVAGE-SPV Maître de conférences M. ARTOIS Marc DEPT-ELEVAGE-SPV Professeur Mme AYRAL Florence DEPT-ELEVAGE-SPV Maître de conférences Stagiaire Mme BECKER Claire DEPT-ELEVAGE-SPV Maître de conférences Mme BELLUCO Sara DEPT-AC-LOISIR-SPORT Maître de conférences Mme BENAMOU-SMITH Agnès DEPT-AC-LOISIR-SPORT Maître de conférences M. BENOIT Etienne DEPT-BASIC-SCIENCES Professeur M. BERNY Philippe DEPT-BASIC-SCIENCES Professeur Mme BONNET-GARIN Jeanne-Marie DEPT-BASIC-SCIENCES Professeur Mme BOULOCHER Caroline DEPT-BASIC-SCIENCES Maître de conférences M. BOURDOISEAU Gilles DEPT-ELEVAGE-SPV Professeur M. BOURGOIN Gilles DEPT-ELEVAGE-SPV Maître de conférences M.
    [Show full text]
  • Cephalic Index in the First Three Years of Life: Study of Children with Normal Brain Development Based on Computed Tomography
    Hindawi Publishing Corporation e Scientific World Journal Volume 2014, Article ID 502836, 6 pages http://dx.doi.org/10.1155/2014/502836 Research Article Cephalic Index in the First Three Years of Life: Study of Children with Normal Brain Development Based on Computed Tomography Wirginia Likus,1 Grzegorz Bajor,1 Katrzyna GruszczyNska,2 Jan Baron,2 JarosBaw Markowski,3 Magdalena Machnikowska-SokoBowska,2 Daniela Milka,1 and Tomasz Lepich1 1 Department of Human Anatomy, Medical University of Silesia, 18 MedykowStreet,BuldingC-1,40-752Katowice,Poland´ 2 Department of Radiology and Nuclear Medicine, Medical University of Silesia, 12 Medykow´ Street, 40-752 Katowice, Poland 3 E.N.T. Department, Medical University of Silesia, 20-24 Francuska Street, 40-027 Katowice, Poland Correspondence should be addressed to Wirginia Likus; [email protected] Received 31 August 2013; Accepted 26 December 2013; Published 4 February 2014 AcademicEditors:Y.Cruz,R.R.deSouza,andP.Georgiades Copyright © 2014 Wirginia Likus et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Cephalic index is a highly useful method for planning surgical procedures, as well as assessing their effectiveness in correcting cranial deformations in children. There are relatively veryew f studies measuring cephalic index in healthy Caucasian young children. The aim of our study was to develop a classification of current cephalic index for healthy Caucasian children upto3 years of age with normal brain development, using axial slice computer tomography performed with very thin slices (0.5 mm) resulting in more accurate measurements.
    [Show full text]
  • Dogs, Cats and Horses in the Scottish Medieval Town Catherine Smith*
    Proc Antiqc So Scot, (1998)8 12 , 859-885 Dogs, cats and horses in the Scottish medieval town Catherine Smith* ABSTRACT Scottish medieval urban sites excavated over lastdecadesthe two have provided abundant evidence animalsofthe which were exploited humanby populations. This paper concernedis with three domesticated reviews horse and speciesdog,and naturethe — the cat — of their relationships with town dwellers. The majority of the excavations reviewed here were funded either wholly or in part by Historic Scotland, in conjunction with the Manpower Services Commission, and research for this paper alsowas funded Historicby Scotland. INTRODUCTION Ove o decadese lasth tw rt , many town site n Scotlani s d have bee e subjecth n f rescuo t e excavations advancn i , buildinf eo g developments. Such excavations have produce wealtda f ho evidence relating to the development of urban centres in the medieval period. Where waterlogging s occurredha r examplfo , n Perthi e , whic s stili h l periodically affecte y locab d l flooding, preservation of organic remains can be particularly good (see, for example, Bowler, Cox & Smith 1995). These remains botf o , h anima pland an l t origin providn ca , ricea h sourc informatiof eo n as to the diet and living conditions of the medieval urban population. Analysis of animal bone assemblage revean sca onlt lno y evidence abou beaste th t s themselves alst ,bu o abou humane th t s who exploite lived an dd alongside them. Hodgson (1983 s revieweha ) summarized dan e dth evidenc domestir efo c animal eastere t siteth sa n so n Scottish seaboard; this paper focused an , son updates, the evidence for, dogs, cats and horses, three species long associated with man, and their Scottise placth n ei h medieval town.
    [Show full text]
  • Human Induced Rotation and Reorganization of the Brain of Domestic Dogs
    WellBeing International WBI Studies Repository 7-26-2010 Human Induced Rotation and Reorganization of the Brain of Domestic Dogs Taryn Roberts University of Sydney Paul McGreevy University of Sydney Michael Valenzuela University of Sydney Follow this and additional works at: https://www.wellbeingintlstudiesrepository.org/morph Part of the Anatomy Commons, Animal Studies Commons, and the Other Animal Sciences Commons Recommended Citation Roberts, T., McGreevy, P, Valenzuela, M., 2010. Human-induced rotation and reorganization of the brain of domestic dogs. PLoS ONE, 5 (7) e11946. doi:10.1371/journal.pone.0011946 This material is brought to you for free and open access by WellBeing International. It has been accepted for inclusion by an authorized administrator of the WBI Studies Repository. For more information, please contact [email protected]. Human Induced Rotation and Reorganization of the Brain of Domestic Dogs Taryn Roberts1*, Paul McGreevy1, Michael Valenzuela2,3* 1 Faculty of Veterinary Science, University of Sydney, Sydney, New South Wales, Australia, 2 School of Psychiatry, University of New South Wales, Sydney, New South Wales, Australia, 3 Brain and Ageing Research Program, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia Abstract Domestic dogs exhibit an extraordinary degree of morphological diversity. Such breed-to-breed variability applies equally to the canine skull, however little is known about whether this translates to systematic differences in cerebral organization. By looking at the paramedian sagittal magnetic resonance image slice of canine brains across a range of animals with different skull shapes (N = 13), we found that the relative reduction in skull length compared to width (measured by Cephalic Index) was significantly correlated to a progressive ventral pitching of the primary longitudinal brain axis (r = 0.83), as well as with a ventral shift in the position of the olfactory lobe (r = 0.81).
    [Show full text]
  • Canine Physiology
    Canine Physiology Copyright © 2018 DSPCA Dog Training Academy published by the Dublin society for the prevention of cruelty to animals www.dspca.ie All rights reserved. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the publisher, except in the case of brief quotations embodied in critical reviews and certain other noncommercial uses permitted by copyright law. For permission requests, write to the publisher, addressed “Attention: Permissions Coordinator,” at the address below. The majority of images have been purchased from Bigstock: Stock Photos & Vector Art, use within course material and not merchandising or branding activities. Those images that have not been acquired from Bigstock, have been acquired under various commons licenses which are specified per image in the list of figures, or independently created by the author. First printing, September 2018 Contents Introduction Body Gait Walk Amble Pace Trot Flying Trot Canter Single Suspension Gallop Double Suspension Gallop Dwarfism & Giantism Head Shapes Dolichocephalic Mesaticephalic Brachycephalic Other Head Shapes Nose Jaws and Teeth Tail Shapes Eyes & Sight Range of Vision Light Receptors Motion Detection Nose & Scent Ears & Hearing Outer Ear Middle Ear Inner Ear Ear Types Paws Coats Colorings Texture Alterations Introduction Aims of Module By the end of this module, the learner will be able to: • Identify the various components of a dog’s body • Understand the mechanism by which dog shapes vary • Itemize the various distinctive markers of the different types of dogs • Discuss the processes of docking and cropping Having both descended from the same mammalian origins, and with traits that go back much further than that, it is no surprise that most of the organs, skeletal structures and even rough placement of components can be mapped from h u m a n s to dogs.
    [Show full text]
  • University of Southampton Research Repository Eprints Soton
    University of Southampton Research Repository ePrints Soton Copyright © and Moral Rights for this thesis are retained by the author and/or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder/s. The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright holders. When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given e.g. AUTHOR (year of submission) "Full thesis title", University of Southampton, name of the University School or Department, PhD Thesis, pagination http://eprints.soton.ac.uk UNIVERSITY OF SOUTHAMPTON FACULTY OF HUMANITIES School of Archaeology The Human-Dog Relationship in Early Medieval England and Ireland (c. AD 400-1250) by Amanda Louise Grieve Thesis for the degree of Doctor of Philosophy September 2012 UNIVERSITY OF SOUTHAMPTON ABSTRACT FACULTY OF HUMANITIES Archaeology Doctor of Philosophy THE HUMAN-DOG RELATIONSHIP IN EARLY MEDIEVAL ENGLAND AND IRELAND (C. AD 400-1250) By Amanda Louise Grieve This thesis aims to explore the human-dog relationship in early medieval England and Ireland (c. AD 400-1250) and so develop an improved understanding of how people perceived and utilised their dogs. In 1974, Ralph Harcourt published a seminal paper reviewing the metrical data for archaeological dog remains excavated from British antiquity. Nearly forty years on, many more dog bones have been excavated and recorded.
    [Show full text]
  • Ancestral Analysis of the French Colonial Moran Cemetery, Biloxi, Mississippi
    The University of Southern Mississippi The Aquila Digital Community Master's Theses Fall 12-2011 Ancestral Analysis of the French Colonial Moran Cemetery, Biloxi, Mississippi Danielle Nicole Cook University of Southern Mississippi Follow this and additional works at: https://aquila.usm.edu/masters_theses Part of the Biological and Physical Anthropology Commons, and the Social and Cultural Anthropology Commons Recommended Citation Cook, Danielle Nicole, "Ancestral Analysis of the French Colonial Moran Cemetery, Biloxi, Mississippi" (2011). Master's Theses. 235. https://aquila.usm.edu/masters_theses/235 This Masters Thesis is brought to you for free and open access by The Aquila Digital Community. It has been accepted for inclusion in Master's Theses by an authorized administrator of The Aquila Digital Community. For more information, please contact [email protected]. ABSTRACT ANCESTRAL ANALYSIS OF THE FRENCH COLONIAL MORAN CEMETERY BILOXI, MISSISSIPPI by Danielle Nicole Cook December 2011 The Moran site (22HR511) in Biloxi, Mississippi, dates from 1719 to 1723 and is the earliest known French Colonial cemetery in the United States. Historical records suggest that those interred likely represent immigrants from Western Europe as well as Africa who were relocated in an effort to colonize the Louisiana Territory. Given the variety of cultural backgrounds at the site, an ancestral analysis of the 25 individuals uncovered has been conducted. Traditional markers such as cranial and tooth morphology and metrics, and enamel composition, were evaluated in all individuals, and DNA was analyzed in five. Stable isotope levels were also assessed to reconstruct diet. The sample consists of two infants, 21 males and three female adults aged 18 to 45.
    [Show full text]
  • Oral Examination of Cats and Dogs
    3 CE CREDITS CE Article 1 Oral Examination of Cats and Dogs ❯❯ Dale Kressin, DVM, DAVCD he oral examination is an integral part Cephalic Index Animal Dental Center— of every general physical examina- Skull shape and size influence the incidence Milwaukee and Oshkosh tion for companion animals. Lesions of certain dental conditions.8 Understanding Glendale, Wisconsin T in the oral cavity may be clinical mani- skull classifications is important because festations of metabolic disease.1–4 Similarly, anatomic variations play a significant role the general physical examination may pro- in the extraoral and intraoral appearance vide important clues to intraoral disease and in dental occlusal relationships.9 processes.5 A general physical examina- The cephalic index categorizes dog and tion is also fundamental to choosing the cat breeds based on skull shape and size.8,10 optimal anesthesia protocol necessary to A relatively wide, short skull character- perform a comprehensive oral examina- izes brachycephalic breeds, such as bull- tion.6 In essence, the two examination dogs, shih tzus, Himalayans, and Persians. At a Glance components complement each other. Mesocephalic breeds, such as Alaskan mal- A comprehensive oral examination amutes, German shepherds, and Labrador Examination of the includes a nonsedated patient evaluation retrievers, have muzzles of intermediate Awake Patient of the head, neck, and oral cavity and a width and length. Dolichocephalic breeds, Page 72 sedated or anesthetized intraoral evalua- represented by borzois, standard poodles, Examination of the tion. A systematic approach using a dental and whippets, have relatively long, nar- Anesthetized Patient chart with an anatomic checklist is most row muzzles.
    [Show full text]
  • Trends in Popularity of Some Morphological Traits of Purebred Dogs in Australia Kendy T
    Teng et al. Canine Genetics and Epidemiology (2016) 3:2 DOI 10.1186/s40575-016-0032-2 RESEARCH Open Access Trends in popularity of some morphological traits of purebred dogs in Australia Kendy T. Teng1*, Paul D. McGreevy2, Jenny-Ann L. M. L. Toribio3 and Navneet K. Dhand3 Abstract Background: The morphology of dogs can provide information about their predisposition to some disorders. For example, larger breeds are predisposed to hip dysplasia and many neoplastic diseases. Therefore, longitudinal trends in popularity of dog morphology can reveal potential disease pervasiveness in the future. There have been reports on the popularity of particular breeds and behavioural traits but trends in the morphological traits of preferred breeds have not been studied. Methods: This study investigated trends in the height, dog size and head shape (cephalic index) of Australian purebred dogs. One hundred eighty-one breeds derived from Australian National Kennel Council (ANKC) registration statistics from 1986 to 2013 were analysed. Weighted regression analyses were conducted to examine trends in the traits by using them as outcome variables, with year as the explanatory variable and numbers of registered dogs as weights. Linear regression investigated dog height and cephalic index (skull width/skull length), and multinomial logistic regression studied dog size. Results: The total number of ANKC registration had decreased gradually from 95,792 in 1986 to 66,902 in 2013. Both weighted minimal height (p=0.014) and weighted maximal height (p<0.001) decreased significantly over time, and the weighted cephalic index increased significantly (p<0.001). The odds of registration of medium and small breeds increased by 5.3 % and 4.2 %, respectively, relative to large breeds (p<0.001) and by 12.1 % and 11.0 %, respectively, relative to giant breeds (p<0.001) for each 5-year block of time.
    [Show full text]
  • Sex, Skull Length, Breed, and Age Predict How Dogs Look at Faces of Humans and Conspecifics
    Europe PMC Funders Group Author Manuscript Anim Cogn. Author manuscript. Published in final edited form as: Anim Cogn. 2018 July ; 21(4): 447–456. doi:10.1007/s10071-018-1180-4. Europe PMC Funders Author Manuscripts Sex, Skull Length, Breed, and Age Predict How Dogs Look at Faces of Humans and Conspecifics Zsófia Bognár, Ivaylo B. Iotchev*, and Enikő Kubinyi Department of Ethology, Eötvös Loránd University, Pázmány Péter sétány 1/c, 1117, Budapest, Hungary Abstract The gaze of other dogs and humans is informative for dogs, but it has not been explored which factors predict face-directed attention. We used image presentations of unfamiliar human and dog heads, facing the observer (portrait) or facing away (profile), and measured looking time responses. We expected dog portraits to be aversive, human portraits to attract interest, and tested dogs of different sex, skull length and breed function, which in previous work had predicted human-directed attention. Dog portraits attracted longer looking times than human profiles. Mesocephalic dogs looked at portraits longer than at profiles, independent of the species in the image. Overall, brachycephalic dogs and dogs of unspecified breed function (such as mixed breeds) displayed the longest looking times. Among the latter, females observed the images for longer than males, which is in line with human findings on sex differences in processing faces. In a subsequent experiment, we tested whether dog portraits functioned as threatening stimuli. We Europe PMC Funders Author Manuscripts hypothesized that dogs will avoid food rewards or approach them more slowly in the presence of a dog portrait, but found no effect of image type.
    [Show full text]
  • Presented Version T NE Canine Skull Morphology; What We Know So Far
    This work has been submitted to NECTAR, the Northampton Electronic Collection of Theses and Research. Conference or Workshop Item Title: Canine skull morphology: what we know so far Creators: Mitchell, C., McCormick, W. D. and Crockett, R. G. M. Example citation: Mitchell, C., McCormick, W. D. and Crockett, R. GR. M. (2016) Canine skull morphology: what we know so far. Seminar Presentation presented to: 5th Postgraduate Research Symposium, Moulton College, NAorthampton, 15 December 2016. Version: Presented version T http://nectar.Cnorthampton.ac.uk/9306/ NE Canine Skull Morphology; What We Know So Far Claire Mitchell BSc (Hons), MSc Supervisory Team: 1st Dr. Wanda McCormick 2nd/DOS Dr. Robin Crockett Why this topic? • Dogs have the greatest phenotypic diversity of all (sub)species – 1.5kg up to 90kg • Dogs are very popular: UK population is estimated at 8.5million (PFMA, 2016) • Currently a lot of scientific interest into the impact of skull shape on health of dogs (Koch et al., 2003; Knowler et al., 2014; McGreevy et al., 2013) • Skull shape categories need refining (Georgevsky et al., 2014) Current Research and Key Findings • Georgevsky et al. (2014) – Observed correlation between cephalic index and intelligence • – Cephalic index is not sufficiently dynamic • Discrepancy between cephalic index and breed categorisation (Andrews Figure 1. Correlation between the cephalic index and the height : length ratio of canine skulls et al., 2015) (n=107) (Andrews et al., 2015) – Positive correlation when height included Current Skull Categories
    [Show full text]