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Abstract

As crossbred dogs gain in popularity, how they express inherited behaviour traits in comparison to their purebred constituent breeds is of interest. We investigated behaviours exhibited by crossbred dogs by focusing on the popular Goldendoodle and Labradoodle crossbreds and comparing them to their corresponding constituent breeds: Standard and Miniature Poodle, Golden Retriever or Labrador Retriever. The data for this study was provided by 5141 volunteer dog owners who filled out the Canine Behavioural Assessment and Research Questionnaire (C-BARQ) online survey. The survey results were used to analyse breed differences in fourteen representative behavioural trait scores: trainability, stranger-directed aggression, owner-directed aggression, dog-directed aggression, dog rivalry, dog-directed fear, stranger-directed fear, non-social fear, touch sensitivity, separation-related problems, excitability, attachment/attention-seeking behaviours, energy and chasing. As expected from a first-generation crossbred (F1), the crossbreds in our study tend to fall between the two constituent parent breeds with some exceptions. Our results suggest that the F1 Labradoodle differed significantly from one of the pure constituent breeds only in dog rivalry, whereas the F1 Goldendoodle behaviour varied from one or more pure constituent breeds in dog rivalry, dog-directed aggression, dog-directed fear, and stranger-directed fear. These results can help advise future dog owners on behavioural trends for particular crossbreds.
Animals2019,9,1162;doi:10.3390/ani9121162www.mdpi.com/journal/animals
Article
ExpressionofBehaviouralTraitsinGoldendoodles
andLabradoodles
VictoriaL.Shouldice
1,
*,A.MichelleEdwards
2
,JamesA.Serpell
3
,LeeNiel
4

andJ.AndrewB.Robinson
1
1
CenterforGeneticImprovementofLivestock,DepartmentofAnimalBiosciences,UniversityofGuelph,
50StoneRoadEast,Guelph,ONN1G2W1,Canada;andyr@uoguelph.ca
2
OntarioAgriculturalCollege,UniversityofGuelph,50StoneRoadEast,Guelph,ONN1G2W1,Canada;
edwardsm@uoguelph.ca
3
DepartmentClinicalSciencesandAdvancedMedicine,SchoolofVeterinaryMedicine,
UniversityofPennsylvania,3800SpruceStreet,Philadelphia,PA19104,USA;serpell@vet.upenn.edu
4
DepartmentofPopulationMedicine,UniversityofGuelph,50StoneRoadEast,Guelph,
ONN1G2W1,Canada;niell@uoguelph.ca
*Correspondence:shouldiv@uoguelph.ca
Received:22October2019;Accepted:12December2019;Published:17December2019
SimpleSummary:Crossbreddogsaregaininginpopularitywiththegeneralpublic,butwedonot
fullyunderstandhowthesecrossbredsbehavecomparedtotheirparentbreedsinregardto
inheritedbehaviourtraits.Becauseofthis,weinvestigatedbehavioursexhibitedbycrossbreddogs
byfocusingonthepopularGoldendoodleandLabradoodlecrossbredsbycomparingthemtotheir
correspondingparentorconstituentbreeds:StandardorMiniaturePoodle,andGoldenRetriever
orLabradorRetriever.Thedataforthisstudywasprovidedby5141volunteerdogownersfrom
acrosstheworldwhofilledouttheCanineBehaviouralAssessmentandResearchQuestionnaire(C
BARQ)onlinesurvey.Thesurveyresultswereusedtoanalysefourteendifferentrepresentative
behaviouraltraitscores.Asexpectedfromafirstgenerationcrossbred(F1),thecrossbredsinour
studytendtofallbetweenthetwoparentbreedswithsomeexceptions.TheGoldendoodle
displayedmoreproblematicbehaviourwhencomparedtoitsconstituentbreeds,whereasthe
LabradoodleonlydifferssignificantlyfromtheMiniaturePoodleindogrivalry.Theseresultscan
helpadvisefuturedogownersonbehaviouraltrendsforparticularcrossbreds.
Abstract:Ascrossbreddogsgaininpopularity,howtheyexpressinheritedbehaviourtraitsin
comparisontotheirpurebredconstituentbreedsisofinterest.Weinvestigatedbehavioursexhibited
bycrossbreddogsbyfocusingonthepopularGoldendoodleandLabradoodlecrossbredsand
comparingthemtotheircorrespondingconstituentbreeds:StandardandMiniaturePoodle,Golden
RetrieverorLabradorRetriever.Thedataforthisstudywasprovidedby5141volunteerdogowners
whofilledouttheCanineBehaviouralAssessmentandResearchQuestionnaire(CBARQ)online
survey.Thesurveyresultswereusedtoanalysebreeddifferencesinfourteenrepresentative
behaviouraltraitscores:trainability,strangerdirectedaggression,ownerdirectedaggression,dog
directedaggression,dogrivalry,dogdirectedfear,strangerdirectedfear,nonsocialfear,touch
sensitivity,separationrelatedproblems,excitability,attachment/attentionseekingbehaviours,
energyandchasing.Asexpectedfromafirstgenerationcrossbred(F1),thecrossbredsinourstudy
tendtofallbetweenthetwoconstituentparentbreedswithsomeexceptions.Ourresultssuggest
thattheF1Labradoodledifferedsignificantlyfromoneofthepureconstituentbreedsonlyindog
rivalry,whereastheF1Goldendoodlebehaviourvariedfromoneormorepureconstituentbreeds
indogrivalry,dogdirectedaggression,dogdirectedfear,andstrangerdirectedfear.Theseresults
canhelpadvisefuturedogownersonbehaviouraltrendsforparticularcrossbreds.
Keywords:genetics;crossbreeding;dogs;behaviour;IGF1;doodles;crossbred;hybrid;CBARQ
Animals2019,9,11622of13
1.Introduction
Itisestimatedthattherearecurrentlyover400differentbreedsofdogsaroundtheworld[1].A
breedisaclosedpopulationofcloselyrelatedanimalswhichgenerallyresultsinindividualswith
verysimilarphysicalattributes,relativelypredictablebehaviour,andinsomecasestheselected
abilitytoperformpredeterminedjobs[1–4].Inaddition,thedogowningpublicismovingbeyond
thelongstandingpurebreedsandembracingcrossbreddogs,withdatabasesofdogbreeds
suggestingthatcrossbreddogsmakeuponethirdoftheworld’sdogpopulationandthatthisportion
ofthepopulationisgrowing[5–7].
Itisnotuncommontoencounterapurposebredcrossbreddognowadaysaspeoplearedrawn
moreandmoretodesignerdogbreedsknownasDoodles[8].Doodlesareacrossbetweenapopular
breedsuchasaLabradorRetrieverorGoldenRetrieverandaPoodle[8].Thisisdonewiththeintent
ofproducinganonsheddinghypoallergenicdogthatissimilartothenonPoodleparent[8].Doodles
arenotnew;theideaofthisgroupofcrossesisoriginallycreditedtoanindividualnamedWally
Conran.WallyworkedfortheRoyalGuideDogAssociationofAustraliainthe1980sandwastrying
tocreateaguidedogthatwasalsohypoallergenic[8].Todothis,hecrossedhisbestbreeding
LabradorwithaPoodle;muchtoWally’ssurpriseheranintoanissuewithpeoplenotwantingto
fosterthecrossbredpuppies[8].Tosolvethis,WallycameupwiththenameLabradoodleand
marketedthiscrossasanewhybriddogbreed[8].Themarketingworkedasthepublicgravitatedto
thisideaofhavingawellloveddogbreedthatwashypoallergenicwithoutshedding[8].
Unfortunately,Wallysooncametorealisethatsincethesedogswerehybrids,theydidnothavethe
samepredictabletemperamentormorphologicalaspectsthatpurebredshave[8].Evenso,thepublic
hastakentothesecrossesandtheirpopularityhasgrownsince[8].Doodleshavefollowedpublic
demandandtrendsindogownershipwithmoreandmorecrossesbeingdeveloped,suchasthe
Cockapoo(CockerSpaniel,Poodlecross),Bernadoodle(BerneseMountainDog,Poodlecross),and
Shepadoodle(GermanShepherd,Poodlecross)tonameafew[8].
Itisgenerallybelievedthatcrossbredsarehealthier,havebettertemperaments,andarebetter
allarounddogsduetotheabsenceofinbreedingdepression[5,9–11].Purebreddogsareknownto
differbetweenbreedsingeneraltemperamentandpersonalitytraits,andalthoughtherehavebeen
manystudies[1,4–6,12]oftheseinheritedbehavioursinpurebreddogs,thereisstillmuchtobe
understoodaboutthespecificlinksbetweenbehaviourandgenetics[4,5,12].Crossbreedingblends
DNAfromdifferentparentbreeds,andwhiletheinteractionandexpressionofallelesisnotfully
understood[3,4,9,11,13],genetictheorywouldsuggestthatcrossbredsshouldexpressbehaviours
intermediatetothoseoftheconstituentbreeds[14].Whilecrossbreedingisthoughttobeusefulfor
combiningfavourablecharacteristicsfromtwobreeds,littleisknownabouthowtemperamentand
personalitychangeswhencrossingtwopurebreddogs,norhowtheexpressedbehaviourofprogeny
relatestothatoftheparentbreeds[4,5,15].Behaviourexpressionincaninesisnotmeasuredona
binaryscalewhereadogeitherexpressesordoesnotexpressthebehaviourinquestion[4].Instead,
behaviourismeasuredonarelativescaleofexpressionanddogs,eveninpurebreds,willexpressa
setbehaviourtodifferentdegrees[4].Itshouldbenotedthatsomepurposebredbehaviours,suchas
herdingandpointing,willonlybepresentinbreedsthathavebeenselectedtopointorherd.
However,mostnonspecializeddogbehaviours(e.g.,fear,aggression,trainability,excitability)are
measuredonaspectrumandshowvariabilitybetweenbreeds[1].Duetothenatureofbehaviour
quantificationandourunderstandingofquantitativegenetics[14],wheretheparentbreedsdifferin
scoreforaparticulartrait,itisexpectedthatcrossbreddogswillexpressanintermediatelevelofthe
behaviour[4].Wedefinehereanintermediatelevelofbehaviourexpressionasonethatfallsbetween
thoseoftheconstituentparentbreeds.Fortraitsthatarescoredonascaleofexpression,that
intermediateexpressionwouldbeexpectedtobetheaverageofthescoresoftheparentbreeds.In
thecaseswheretheconstituentparentbreedsdonotdiffersignificantlyfromoneanotherinaverage
behaviourtraitexpressionscore,wewouldexpectthecrossbredstobeconsistentwiththataverage
expressionscoreoftheparentbreedsaswell.Withtheincreaseinpopularityofcrossbreeds,itis
importanttofillthegapsincurrentknowledgetoimproveourunderstandingofthewaysinwhich
crossbreddogtemperamentandpersonalitycomparetothoseoftheirconstituentbreeds.
Animals2019,9,11623of13
Ourobjectivewastoinvestigatebehavioursexhibitedincrossbredsandcomparetheexpression
ofthosebehaviourstotheexpressionofthesamebehavioursbytheconstituentpurebreeds.Itis
widelybelievedthatanF1hybridshouldinheritpredictablebehaviourasfirstdescribedbyDarwin
[16].WefocusedonLabradoodleandGoldendoodle,whichresultfromcrossingaStandardPoodle
oraMiniaturePoodlewitheitheraLabradorRetrieveroraGoldenRetriever.Asalloftheparent
breeds,includingthepoodles,wereusedforhuntinggamebirds,itisthoughtthatthesedogbreeds
wouldbemoresimilartooneanotherthantononretrieverbreedsandcrosses,suchasthe
Shepadoodle.BecausetheMiniaturePoodleandStandardPoodlearetwodifferentbreedsasdefined
bytheCanadiankennelclub,andsincetheCanineBehaviouralAssessmentandResearch
Questionnaire(CBARQ)databasedoesnotaskownersforpedigreeinformation,itwasnecessaryto
comparebothPoodletypestotheDoodlecrosses.Thus,wepredictedthattheLabradoodleand
Goldendoodle,havingparentbreedsfromsimilarworkingbackgrounds,wouldbesimilartotheir
parentbreedswithlittlebehaviouraltendencytowardsoneortheotherparentbreed[15].
Totestthisprediction,weareutilizingtheCanineBehaviouralAssessment&Research
Questionnaire,whichisawellvalidatedquestionnairebasedresearchtoolthathasbeenused
extensivelyinpeerreviewedstudiesondogbehaviour[17].CBARQisanownercompleted
questionnaireoriginallydevelopedbyYuyingHsuandJamesSerpell[18],thatassesses14different
behaviouraltraitsbasedonquestionsreflectingtheresponsesofdogstovariousreallifescenarios.
Datacollectionhasbeenongoingsince2005,andthecurrentdatabasehasover50,000dog
behaviouralrecordsfromaroundtheworldandincludesover300differentcrossbredsandpurebred
dogs[17,18].Thedatabasewasoriginallycreatedtobeusedforassessingpotentialproblematic
behaviourwithintheworkingandpetdogcommunities[18].Becauseofthelargedatabase,weare
abletocollectphenotypicbehaviouralprofileswhichallowustoassessbehaviouralprofilesofthe
purebredsandDoodlesinourstudyevenintheabsenceofpedigreeinformation.
2.MaterialsandMethods
2.1.DataCollection
ThedataforthisstudyweregeneratedfromvolunteerdogownerswhofilledouttheCBARQ
onlinesurveyhostedbytheSchoolofVeterinaryMedicine,UniversityofPennsylvania
(https://vetapps.vet.upenn.edu/cbarq/).TheCBARQprojectwaslaunchedin2005andsurveydata
haveaccumulatedsincethattime.DataforthisstudywereextractedandcleanedinApril2019.Data
werecleanedbyremovingidentifiersofownerssuchasemails,noncompleteCBARQsurveys,and
dogswithhealthissuessuchashypothyroid,hyperthyroid,Addison’s,severeallergies,oranydogs
withadiseasethatrequiresmedicationsthatmayalterbehaviour.Dogownersareabletocomplete
theCBARQsurveyonlineandwereoriginallymadeawareofthesurveyviaveterinaryoffices,dog
trainers,socialmedia,petmagazinesandwordofmouth[17].ThesurveyisorganisedbyownerID
andeachvolunteercancompletethesurveyforuptoamaximumof10dogs.Ownereffectisa
concerninthecurrentdatasetduetotherelativelysmallnumberofcrossbreds,asmultidog
householdscouldpresumablyhavesimilarbehavioursduetoenvironment[18].Wehaveaddressed
theseconcernsinourstatisticalmodel.DuetothenatureoftheCBARQproject,wedonothave
pedigreeinformationbutdohaveinformationonwherethedogwasacquired.Wealsohadno
controloverwhofilledoutthesurvey.
2.2.BehaviouralMeasures
Fourteendifferentrepresentativebehaviouraltraitswerepreviouslyextractedbyfactoranalysis
andwereincludedinthisstudy:trainability,strangerdirectedaggression,ownerdirected
aggression,dogdirectedaggression,dogrivalry,dogdirectedfear,strangerdirectedfear,nonsocial
fear,touchsensitivity,separationrelatedproblems,excitability,attachment/attentionseeking
behaviours,energyandchasing.Thesescoresweredeterminedbyownersratingtheirdogs’
behaviourin100differentscenarios(e.g.,whenapproacheddirectlybyanunfamiliaradultwhile
beingwalked/exercisedonaleash)[18].Eachquestionwasscoredonascalefrom0–4todenotethe
Animals2019,9,11624of13
frequency(0=never;1=seldom;2=sometimes;3=usually;4=always),orseverity(0=nosignsof
thebehaviour;1–3=mildtomoderatesignsofthebehaviour;4=severesignsofthebehaviour)[18].
Fromthere,questionswereorganisedintoeightcategories,threeofwhicharebasedonseverityand
fivebasedonthefrequencyofoccurrence[18].Foreachfactor,scoresfortherelatedquestionswere
combinedtoproduceanaveragescorethatwasusedforanalysis.
2.3.StatisticalAnalyses
SeparateanalyseswerecompletedforLabradoodleandGoldendoodlecrosses.Thus,thetwo
analysesincluded(1)MiniaturePoodle,StandardPoodle,LabradorRetrieverandLabradoodle(LD),
and(2)MiniaturePoodle,StandardPoodle,GoldenRetriever,andGoldendoodle(GD).Therewere
atotalof5141dogsinbothdatasetswith166Labradoodles,2597LabradorRetrievers,157
Goldendoodles,1366GoldenRetrievers,597StandardPoodlesand258MiniaturePoodlesmaking
3618dogsintheLDanalysisand2378dogsintheGDanalysis.Individualdogswereassumedtobe
unrelatedandwedonotknowwhichPoodletypewasusedforeachofthecrossbreddogs.
AllstatisticalanalyseswereperformedusingSASversion9.4;analyseswereconsidered
significantifp≤0.05[19].Outcomevariableswereexaminedusingmixedlinearregressionmodels
usingtheGLIMMIXprocedure.Comparisonswereassessedusingadjustedleastsquaremeansand
adjusted(usingTukeyKrameradjustment)toaccountfortheunevensamplesizebetweenour
breeds.Thecountrywasincludedinthemodelsasafixedeffect.Thesingletraitlinearanimalmodel
usedintheanalysiswas:
Yijklmnop=μi+breedj+sexk+countryl+whereacquiredm+ageatevaluationn+ownero+ap+eijklmnop
where,
o yijklmnisthebehaviouralobservationforanimalo;
o μistheoverallmeanfortheobservationontraiti;
o breed(j)wasafixedeffect(levelsareequaltoLabradoodle,LabradorRetriever,Goldendoodle,
GoldenRetriever,MiniaturePoodleandStandardPoodle);
o sexisafixedeffect(k,beingeitherfemaleormale);
o countryofresidenceoftheownercompletingthesurveyisafixedeffectrepresentingthe
environmentandculturethedogisfrom;
o whereaquiredisafixedeffectofwhereanowneracquiredtheirdog(m,beingeitherabreeder,
petstore,bredbyowner,shelter,friendorrelative,strayorother);
o ageatevaluationisthefixedeffectoftheageoftheanimalwhenitwasevaluatedintheCBARQ
system(n,isthecategoryofthedogs’age;puppy,junior,adult,senior);
o owneristherandomeffectofoonthehouseholdinteraction;
o aistherandomadditivegeneticeffectofanimalp;
o theassumptionsfortherandomeffectsinclude:e ~ N0, Iσ
σ
istheresidualvariance,andI
isanidentitymatrix.
Forallmodels,residualsweretestedforhomogeneityandnormalitybyusingtheShapiroWilk
testandplots.Duetoalackofparentageinformation,inaseparateanalysis,weattemptedtodiscern
thecontributingbreedofPoodleintheLabradoodleandGoldendoodlecrossbredsbyanalysingthe
weightofthecrossbredsrelativetotheweightofthepurebredsusingtheProcunivariatefunction
inSASforallbreedsintheLDandGDanalysis.
3.Results
3.1.Labradoodle
FortheLDanalysis,fourbehaviouralscoresdifferedbetweenbreeds(Table1,Figure1).
LabradorRetrieverandStandardPoodlescoresdidnotdiffersignificantlyfromthoseof
Labradoodlesforanybehaviourcategory.Incontrast,MiniaturePoodlesscoredsignificantlyhigher
thanLabradoodlesfordogrivalry.TheMiniaturePoodlehadahigherscorethantheLabrador
Animals2019,9,11625of13
Retrieverinbothnonsocialfearandseparationrelatedproblems,whereastheStandardPoodlehad
alowerscorethantheMiniaturePoodlefortouchsensitivity.Therewereanumberofinteractions
betweenBreedandotherfixedeffects.TheinteractionwithWhereAcquiredwassignificantforallof
themodels,andinteractionswithSex,Country,andAgeatEvaluationweresignificantformostof
themodels.
Figure1.BreedaveragebehaviouralscorescollectedfromCBARQfortheLabradorRetrievers,
Labradoodles,StandardPoodlesandMiniaturePoodles.Thetraitsdisplayedabovewerefoundto
havesignificantdifferences(p<0.05)betweenthebreedsintheanalyses.Significantdifferences
betweenbreedsaremarkedwithaandb.abindicatesthatthisbreeddidnotvarysignificantlyfrom
eitherbreedaorbreedb.Behaviouralscoresarerankedfrom0–4,zerobeingneverand4being
always.Errorbarsonthegrapharestandarderror.
3.2.Goldendoodle
TheGDanalysishadsevenbehaviouralscoresthatdifferedbetweenthebreeds(Table2,Figure
2).TheStandardPoodlehadalowerscorethantheGoldenRetrieverforownerdirectedaggression.
TheGoldendoodledifferedfromtheGoldenRetriever,StandardPoodleandMiniaturePoodlein
dogdirectedaggressionwithahigherscorethantheotherthreebreeds.TheMiniaturePoodlehad
thehighestaveragescorefordogrivalryoutofallfourbreedsintheGD.TheGoldendoodlehadthe
highestaveragescorefordogdirectedfearandwassignificantlydifferentthantheStandardPoodle
whichhadthelowestaveragescoreforthistraitoutofallthebreedsinthisanalysis.TheGolden
Retrieverscoredsignificantlylowerforstrangerdirectedfearonaveragewhencomparedtothe
Goldendoodle.Ontheotherhand,theGoldendoodledidnotdiffersignificantlyfromtheMiniature
Poodleforaveragescoresforownerdirectedaggression,dogdirectedfear,strangerdirectedfear,
touchsensitivity,andseparationrelatedproblems.TheMiniaturePoodledifferedfromtheGolden
RetrieverandStandardPoodlewithhigheraveragescoresforbothdogrivalry,andtouchsensitivity.
Animals2019,9,11626of13
Table1.MeanownerreportedCanineBehaviouralAssessmentandResearchQuestionnaire(CBARQ)scoresformainbehaviouralcategoriesforLabradorRetrievers(n
=2597),Labradoodles(n=166),StandardPoodles(n=597)andMiniaturePoodles(n=258).Modelinteractionsbetweenbreedandotherfixedeffectsarealsoreported.
Breedcomparisonindicateswhenbreedsdiffered.
Trait
ModelEffectBreedMeanBehaviouralScores
BreedBreed×
Sex
Breed×
Country
Breed×Where
Acquired
Breed×Ageat
Evaluation
Labrado
r
RetrieverLabradoodleMiniature
Poodle
Standard
Poodle
Trainability ● ● ● ● 2.632.732.542.70
Strangeraggression ● ● ● ● 0.470.560.650.57
Owneraggression ●● ● 0.230.120.320.16
Dogaggression ● ● ● ● 0.950.620.920.74
DogRivalry●0.44a0.19a1.02b0.37a
Dogfear0.740.900.780.73
StrangerFear0.500.690.650.66
NonSocialfea
r
●  ● ● 0.68a0.91ab1.04b0.72ab
Touchsensitivity ●  ● ● 0.72ab0.76ab1.04a0.59b
Separationrelatedproblems ●●● ● 0.55a0.76ab0.93b0.62ab
Excitability2.002.042.281.93
Attachment/attentionseekingbehaviours  ● ● ● ● 2.042.162.031.98
Chasing    ● ● 1.841.651.861.97
Energy2.112.202.042.07
Significantdifferencefortheindicatedvariableorinteraction(p<0.05).a,bDifferentletterswithinthesamerowdenotesignificantdifferences(p<0.05).Boldedtextindicatetraits
thatdisplayedsignificantdifferencesbetweenbreeds.
Animals2019,9,11627of13
Table2.MeanownerreportedCBARQscoresformainbehaviouralcategoriesforGoldenRetrievers(n=1366),Goldendoodles(n=157),StandardPoodles(n=597)and
MiniaturePoodles(n=258.Modelinteractionsbetweenbreedandotherfixedeffectsarealsoreported.Breedcomparisonindicateswhenbreedsdiffered.
Trait
ModelEffectBreedMeanBehaviouralScores
BreedBreed×
Sex
Breed×
Country
Breed×Where
Acquired
Breed×Ageat
EvaluationWeeks
Golden
RetrieverGoldendoodleMiniature
Poodle
Standard
Poodle
Trainability2.612.912.542.69
Strangeraggression  ● ● ● ● 0.560.850.670.56
Owneraggression0.35a0.19ab0.32ab0.17b
Dogaggression0.73a1.68b0.92a0.74a
DogRivalry 0.42a0.37a1.05b0.38a
Dogfear  0.82ab1.44a0.79ab0.74b
StrangerFea
0.48a1.16b0.65ab0.66ab
NonSocialfear0.931.121.040.73
Touchsensitivity 0.65a0.75ab1.04b0.61a
Separationrelatedproblems0.51a0.93ab0.94b0.63ab
Excitability   ● ● 1.972.212.291.94
Attachment/attentionseekingbehaviours  ● ● 1.892.022.011.98
Chasing1.742.231.841.98
Energy2.012.052.052.04
●Significantdifferencefortheindicatedvariableorinteraction(p<0.05).a,bDifferentletterswithinthesamerowdenotesignificantdifferences(p<0.05).Boldedtextindicatetraits
thatdisplayedsignificantdifferencesbetweenbreeds.
Animals2019,9,11628of13
Figure2.BreedaveragebehaviouralscorescollectedfromCBARQforGoldenRetrievers,
Goldendoodles,StandardPoodlesandMiniaturePoodles.Thetraitsdisplayedabovewerefoundto
havesignificantdifferences(p<0.05)betweenthebreeds.Significantdifferencesbetweenbreedsare
markedwithaandb.abindicatedthatthisbreeddidnotvarysignificantlyfromeitherbreedaor
breedb.Behaviouralscoresarerankedfrom0–4,zerobeingneverand4beingalways.Errorbarson
thegrapharestandarderror.
Duetothelackofpedigreeinformationinthecurrentstudy,weexaminedthedistributionof
dogweightforboththeLDandGDanalysestodetermineifwecouldpredictMiniatureorStandard
PoodleasthepoodleparentbreedoftheGoldendoodlesorLabradoodles.Theweightsofthe
GoldendoodleandLabradoodlewereevenlydistributedbetweentheStandardandMiniaturePoodle
sodifferentiationofthepoodlebreedinthecrossbredswasnotpossible.
4.Discussion
AstheLabradoodleandGoldendoodleareexpectedtobeF1crosses,onewouldexpectthese
crossbredstodemonstratebehaviouralscorephenotypesthatareintermediatetotheirpurebred
parentbreeds.Thiswasgenerallytrueinthisstudywithsomenotableexceptions.Wefoundthatthe
LabradoodledifferedfromtheMiniaturePoodleforaveragescoreinonlyonetrait,dogrivalry,and
theGoldendoodledifferedfromvariousdifferentparentbreedsforaveragescoreinfourtraits—dog
directedaggression,dogdirectedfear,strangerdirectedfear,anddogrivalry.
ThereweresomesimilaritiesacrosstheLDandGDanalyses;forinstance,theMiniaturePoodle
hadthehighestaveragescorefordogrivalryforboththeLDandGDanalyses.Inthisstudy,dog
rivalrywasdefinedas“dogshowsaggressiveorthreateningresponsestootherfamiliardogsinthe
samehousehold”[20].However,rivalrydoesoccurmorefrequentlywithMiniaturePoodlesthanin
theotherpure‐andcrossbreeds,whoseaveragescoresarecloseto“almostnever”frombothLDand
GDanalyses.
DifferencesinseparationrelatedproblemswerenotedinboththeLDandtheGDanalysesas
well,withseparationrelatedproblemsdefinedas“Dogvocalizesand/orisdestructivewhen
Animals2019,9,11629of13
separatedfromtheowner,oftenaccompaniedorprecededbybehaviouralandautonomicsignsof
anxietyincludingrestlessness,lossofappetite,tremblingandexcessivesalivation.”[18].Inboththe
LDandGDanalyses,theMiniaturePoodlehadthehighestaveragescoreforseparationrelated
problems,andwassignificantlyhigherthantheparentretrieverbreeds,withthecrossbredsshowing
intermediateaveragescoresthatdidnotdiffersignificantlyfromeitherparentstock.Dogswith
higherlevelsofseparationrelatedproblemshavebeenknowntocauseselfharmduetoescape
attempts[21].Notonlydoseparationrelatedproblemshaveanegativeimpactonadog’swelfare,
buttheyalsonegativelyimpactthehumananimalbondandinsomecasesleadtorehomingofthe
animal[21].FurtherresearchisneededtodeterminewhetherDoodlesresultingfromMiniature
PoodlecrossesaremorepronetothisbehaviourproblemthanthoseresultingfromStandardPoodle
crosses.
ThelasttraitcommontoboththeLDandGDanalysisistouchsensitivity.Thisasdefinedas
“Dogshowsfearfulorwaryresponsestopotentiallypainfuloruncomfortableprocedures,including
bathing,grooming,nailclippingandveterinaryexaminations”.Aswiththeothersimilartraits,the
MiniaturePoodledifferedthemostfromthebreedswithanaveragescoreof1.04.IntheGDanalysis,
theMiniaturePoodledifferedfromboththeGoldenRetrieverandtheStandardPoodle,butinthe
LDanalysis,onlytheStandardPoodledifferedsignificantlyfromtheMiniaturePoodle.
NonsocialfearistheonlytraitthatshowedsignificantdifferencesintheLDanalysisthatwas
notalsofoundintheGDanalysis.Nonsocialfearisdefinedas“Dogshowsfearfulorwaryresponses
tosuddenorloudnoises(e.g.,thunder,trafficandunfamiliarobjectsandsituations).”TheMiniature
Poodlehadthehighestaveragescoreinthisanalysisandscoredsignificantlyhigherthanthe
LabradorRetriever.Labradoodleshadanintermediateaveragescorebutdidnotdifferfromanyof
theparentbreeds.ThesescoresshowthattheMiniaturePoodledisplayssomenoiseandobject
aversion,whiletheLabradorRetrieverrarelyshowssuchaversion.Thismaysuggestthatthe
MiniaturePoodlehasbeendirectlyorindirectlyselectedtobefurtherremovedfromitsoriginsasa
huntingdogthantheotherpurebreds.Thistrait,likeseparationrelatedproblems,mayalsohavean
impactonthedog’swelfare,andthereisalsoevidencethatthesetwobehaviouralissueshavean
impactoneachother,asthedogisalreadyinananxiousstatewhentheownerleaves[21].
TheGoldendoodlehadthehighestaveragedogdirectedaggressionscoreintheGDanalysis.
Dogdirectedaggressionwasdefinedas“Dogshowsthreateningoraggressiveresponseswhen
approacheddirectlybyunfamiliardogs”[18].ThiswastheonlytraitintheGDanalysiswherethe
Goldendoodledifferedsignificantlyfromitsconstituentparentbreeds.Theotherbehaviournotedin
theGDanalysiswasOwnerdirectedaggressionwhichwasdefinedas“Dogshowsthreateningor
aggressiveresponsestotheownerorothermembersofthehouseholdwhenchallenged,
manhandled,staredat,steppedover,orwhenapproachedwhileinpossessionoffoodorobjects.”
[18].TheGoldenRetrieverhadhigheraveragescoresforownerdirectedaggressionthanthe
Goldendoodle,StandardPoodle,andMiniaturePoodle.
TheGoldendoodleshowedahigheraveragescoreforstrangerdirectedfearintheGDanalysis
comparedtothepurebreds,thatwasnotobservedbetweentheLabradoodleandpurebredsinthe
LDanalysis.Strangerdirectedfearisdefinedas“Dogshowsfearfulorwaryresponseswhen
approacheddirectlybyastranger”[18].Formosttraits,theGoldendoodlewasintermediatetothe
parentbreeds,butinthecaseofstrangerdirectedfear,theaveragescorefortheGoldendoodlewas
higherthantheGoldenRetriever.ThelastbehaviourthatstoodoutintheGDanalysiswasdog
directedfear,astheGoldendoodledifferedsignificantlyfromtheStandardPoodle.The
Goldendoodlehadthehighestaveragescorefordogdirectedfear;comparedtotheGoldenRetriever,
StandardPoodleandMiniaturePoodlewhichallhadmuchlowerscores.Dogdirectedfearwas
definedas“Dogshowsfearfulorwaryresponseswhenapproacheddirectlybyunfamiliardogs.”
[18].
Basedonouranalysesofthepurebredanimalsinthisstudy,theMiniaturePoodledifferedthe
mostfromtheotherpurebreeds,includingtheStandardPoodle.WealsoobservedtheGoldendoodle
differentiatingfromoneorbothparentbreeds.TheGoldendoodledifferedsignificantlyfromaparent
breedindogdirectedaggression,dogdirectedfear,andstrangerdirectedfear.Thesedifferences
Animals2019,9,116210of13
maybelinkedtohybridvigour[1,22,23].Hybridvigourisoneofthereasonsmanyofthepetowning
publicacquireaDoodlecross;crossbredsareperceivedtobeahealthieranimalsincehybridvigour
hasaproveneffectonfitnesstraitsinotherspeciessuchaslivestock[22].However,wedonotfully
understandtheeffectofhybridvigourinthedomesticateddog,norhowhybridvigouraffects
behaviour[22].AninbreedingstudyconductedbyMellanbyetal.[23]lookedat25differentbreeds,
includingtheGoldenRetrieverandLabradorRetriever.TheauthorsfoundthattheGoldenRetriever
wasoneofthemostinbredbreedsexaminedintheirstudy.Asaresult,theGoldendoodlewouldbe
expectedtohaveagreatereffectofhybridvigourincomparisontotheLabradoodle[22,23]andthus,
potentiallygreaterdifferencesinbehaviourfromtheconstituentbreedsthantheLabradoodle.
ThedifferencesweareobservingintheMiniaturePoodlemaybeduetothecontributionofthe
expressionoftheinsulinlikeGrowthFactor1(IGF1)genewhichaffectsthegrowthandstatureofthe
dog.IGF1isexpressedinmanytoyorminiaturebreedsbutisrareinlargebreeds[1,24,25].
Interestingly,studieshavefoundthattherearesignificantlylowerlevelsofcirculatingIGF1inthe
serumofMiniaturePoodlesincomparisontotheStandardPoodle[1,26–28].Someevidenceshows
thatnotonlyisthisgeneassociatedwithgrowth,butitisbelievedtobelinkedtotemperamentas
well[1,24,29].AstudyconductedbyUhdeandcolleagues[29]bredGermanShorthairedPointersfor
fearfulornervousbehaviour,andtheyfoundaninverselinearcorrelationbetweenfearfulbehaviour
andtheexpressionofIGF1.ThissuggeststhatlowerlevelsofIGF1expressionmakesmallerdogs
morefearful,reactive,excitable,andsensitivetotouch[1,24,29].Withoutpedigreeinformation,we
unfortunately,cannotknowifthereisanydifferenceinbehavioursbetweenDoodlescrossedwitha
MiniaturePoodleorStandardPoodle;however,ourresultssuggesttheremaybesomedifferential
expressionofIGF1occurring.Forinstance,weobservedthattheMiniaturePoodledifferedfromthe
otherpurebreddogsindogrivalry,nonsocialfear,touchsensitivity,separationrelatedproblems,
dogdirectedaggression,strangerdirectedfear,anddogdirectedfear,whichareallbehaviours
consideredtobehigheramongsmallbreedsandcouldberelatedtoexpressionofIGF1[1,24,29].
ThesebehavioursthatmaybeassociatedwithIGF1expressionarethesamebehavioursinourstudy
thatwesawsignificantaveragescoredifferencesbetweentheLDandGDanalyses.IftheIGF1gene
doesinfluencefearandaggression,itcouldcreatewelfareimplicationsforthedogswiththisgene
expression.Fearisanegativeaffectivestatethatcanimpairanimalwelfare,particularlywhenit
occursathighlevelsandisprotracted[12,21,27].Itcanalsoleadtoaggressionandotherbehaviour
problemsthatresultinabreakdownofthehumananimalbondandincreasethelikelihoodof
euthanasiaorrelinquishment[12,21].Basedonourscoresfordogdirectedaggressionanddog
directedfearbehavioursintheGoldendoodle,itwouldappearthiscrossexpresseselevatedlevelsof
aggressionandfearbasedbehaviours,andthattheseissuesarenotpresentintheLabradoodle.
Althoughtheaveragescoresobservedinthecurrentstudyarerelativelylowoverall,itisimportant
thatownersareawareofpotentialimpactsondogbehaviourandwelfare[12,21,27].
PreviousresearchhasfoundthattheLabradorandGoldenRetrievershavecomparativelylow
occurrencesofaggressivebehaviours[17].Incontrasttothesepredictionsaboutoneoftheir
constituentparentbreeds,weobservedelevatedlevelsofdogdirectedaggressionfromthe
Goldendoodle,andwealsosawhigherlevelsofdogdirectedfearandstrangerdirectedfear.This
correspondstowhatotherstudieshavefoundwhenexaminingIGF1expressionandcrossbreddogs
[7,26,28,29].BennettandRholf[7]examinedcrossbreddogsandfoundthemtobemorefearful,
aggressive,vocalandneuroticwhencomparedtopurebreddogs.Temesiandcolleagues’[30]study
alsoagreedwithBennettandRholfs’[7]findingsastheytoonotedneuroticism,dogdirectedfear,
andhumandirectedfearincrossbreeds.Similarly,HsuandSun[31]foundthatmixedbreeddogs,
ingeneral,seemtohaveahigherexpressionofaggressionandfearbasedbehaviours.Thisdifference
incrossbredscouldbeattributableinparttoheterosis,althoughthesestudiesdidnotdifferentiate
betweenF1hybridssuchastheGoldendoodleandLabradoodleandmixedbreedsofunknown
origins[4,22,23].Retainedheterosismaybelowerinmixedmultibreeddogscomparedtoheterosis
inF1crosses[4]
WhiletheinfluenceoftheIGF1geneisonepotentialexplanationforthebehaviouraldifferences
observedinMiniaturePoodles,behaviourinthesedogsmightalsohavebeeninfluencedby
Animals2019,9,116211of13
differencesinthewaysthatsmallandlargedogsaretreatedbyowners.Arhantandcolleagues[32]
foundthatthesizeofadoghasanimpactonhowdogownersinteractwiththeanimalandthat
smallerdogsweremorelikelytohaveunfavourablebehaviours,suchasdisobedience,increased
aggression,excitabilityandfearfuloranxiousbehaviours[32–35].Theauthorssuggestedthis
differenceisdueinparttohowownersofsmalldogsinteractwiththeiranimals,withownersof
smalldogsshowingmoreinconsistencyintheirinteractions,andreportinglowerlevelsoftraining,
exerciseandhumandogplaybehaviour[34–36].Poorbehaviourfromsmallerdogsisalsotolerated
betterbythepublic,asdemonstratedbystatisticsondogbiteoccurrence[34,35].Onaverage,smaller
breeddogsbitemorefrequentlyandleavelacerationsontheirhumanbitevictims,whilelargerbreed
dogsdonotbiteasoftenassmallerdogsbutcreatemoredamage[34].Becauseofthis,largerdogs
thathavebrokenskinaremuchmorelikelytobeeuthanizedduetoaggressivebehaviourthan
smallerdogsthatdisplaythesamebehaviourbutcreatelessdamage[34].Ownerlifestyle,
demographics,ethnicityandlivinglocationmayalsoplayaroleinhowsmalldogownersinteract
withtheirdog[34].Becauseofthistolerancetowardspoorbehaviourinsmallerdogs,itwouldnot
besurprisingthatlessselectionagainstpoorbehaviourmayoccurinsmallbreeddogs[34,35].There
isalsoevidencethatsuggestsbodysize,weightandskullshapemayhaveanimpactondifferent
behaviourswhichmayprovidesomeexplanationforthevariationobservedbetweenthelargeand
smallpurebredsincludedinthecurrentstudy[35].Furtherresearchisneededtodeterminewhether
thetypeofPoodlethatisusedinthecrossinfluencesthebehaviourofDoodlebreeds.
Aswithallresearch,thisstudyhascertainlimitationsthatmighthaveinfluencedthefindings
andconclusions.Theremaybesomebreedidentificationerrorsinthedataforthedogsincludedin
thecurrentstudy;CBARQrecordsarebasedonownerreports,thus,bothpurebredsandcross
breedsmightbemisclassifiedbyowners.Forthesamereason,wealsodonotknowhowrelatedthe
dogsinthestudyareoriftheyarefromthesamebreederororigin.Ownerinformationwas
accountedfor,andwehaveassumednorelationshipbetweendogsandthatallcrossesareF1crosses.
Inaddition,wehadarelativelysmallsamplesizeofcrossbreddogswhencomparedtoourpurebred
animals,whichmayimpactthegeneralisabilityofourresults,inspiteoftheTukeyKramer
adjustmentusedtoaccountforunbalanceddata
5.Conclusions
AsexpectedfromanF1cross,thecrossbreedstendedtoexpressintermediatebehaviour
betweenthetwoconstituentpurebreedswithsomeexceptions.TheGDanalysisshowedthemost
differencebetweentheconstituentpurebreeds.Evenwiththesedifferences,theGoldendoodleonly
differedsignificantlyfromoneormoreoftheparentbreedsindogdirectedaggression,dogdirected
fear,strangerdirectedfear,anddogrivalry.ThecrossbredintheLDanalysisshowedthefewest
behaviouraldifferencesfromtheotherparentbreedswiththeexceptionofdogrivalry,butthatwas
duetotheMiniaturePoodledifferingfromtheotherbreedsintheLDanalysis.Theseresultssuggest
thatdifferentialexpressionoftheretrieverbasedbehaviouraltendenciesisdependentonthe
retrieverorigin.FurtherresearchisneededtodeterminewhetherIGF1expressionmightplayarole
inbehaviouraltendenciesforpoodlecrosses,andhowthisisinfluencedbycontributionsfromthe
nonpoodleparent.Overall,theresultsofthecurrentstudycanassistbreedersandownersin
predictinglikelybehaviouralphenotypesforLDandGDcrossbreds,andthisinformationcanbe
usedtoassistownersinselectingbreedsthatbestfittheirneedsandexpectations.
AuthorContributions:Conceptualization,V.L.S.,L.N.,J.A.S.andJ.A.B.R.;methodology,V.L.S.,L.N.and
J.A.B.R.;software,V.L.S.,L.N.,A.M.E.andJ.A.B.R.;formalanalysis,V.L.S.,L.N.,A.M.E.andJ.A.B.R.;data
curation,J.A.S.;writing—originaldraftpreparation,V.L.S.;writing—reviewandediting,V.L.S.,L.N.,J.A.S.,
M.E.andJ.A.B.R.
Funding:Thisresearchreceivednoexternalfunding.
ConflictsofInterest:Theauthorsdeclarenoconflictofinterest.
Animals2019,9,116212of13
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This article provides a comprehensive overview of methods for evaluating the suitability of trainee dogs for assistance and guide work. It presents both current practices in industry as well as modern techniques with the aim of identifying important behavioural traits. It is divided into (1) selection and training methods, including breed, genetics, and training programme considerations; (2) behaviour assessment methods such as traditional test batteries, individual ratings and observational tests plus emerging techniques such as canine activity monitoring; (3) physiological assessment methods including cardiac, respiratory and hormonal biomarkers. Assistance dog organisations around the world share a similar overall structure of their training programmes and behavioural assessment methods, however the implementation details vary as no standardised technique is widely employed. Physiological indicators have demonstrated great potential to estimate affective states and personality characteristics such as emotional regulation and coping style. Further investigation is encouraged to validate and define the use of physiological measures to complement behavioural scores in evaluating the suitability of prospective dogs for assistance work. A number of commercially available off-the-shelf (COTS) devices are discussed in the terms of their suitability and reliability for monitoring canine activities and cardio-respiratory parameters. This interdisciplinary collaboration is key to further understanding the connection between behaviour and physiology, allowing a more complete evaluation of an individual’s capability which will ultimately enable a highly accurate prediction of their training outcome. We recommend that assistance dog organisations and researchers work together to design new assessment protocols considering validated practices and promising techniques from state-of-the-art literature.
... Although the median age of the brachycephalic group (3.31 years) was statistically lower than each of the other three groups, it is noteworthy that the median ages for crossbreds (3.74 years) was numerically much closer and younger than the median ages for mesocephalic (5.33 years) and dolichocephalic (5.07 years) types. The relative youth of the crossbred group may reflect the recent surge in popularity of designer crosses such as labradoodle and cockapoo that will have had the effect of pulling the median age of the overall crossbred group downwards 60 . ...
... and crossbred dog types (Supplementary A). Crossbred dogs included all dogs that were not recorded with a standard recognised breed name41,95 ; crossbreds included genuine 'mixed-breed' mongrels as well as dogs where some breed parentage information was recorded including those that are so-called designer types such as labradoodle and cockapoo60 . Mesocephalic, dolichocephalic and crossbred dog types were further grouped as non-brachycephalic types for the purposes of disease risk analyses. ...
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Brachycephalic dog breeds are regularly asserted as being less healthy than non-brachycephalic breeds. Using primary-care veterinary clinical data, this study aimed to identify predispositions and protections in brachycephalic dogs and explore differing inferences between univariable and multivariable results. All disorders during 2016 were extracted from a random sample of 22,333 dogs within the VetCompass Programme from a sampling frame of 955,554 dogs under UK veterinary care in 2016. Univariable and multivariable binary logistic regression modelling explored brachycephaly as a risk factor for each of a series of common disorders. Brachycephalic dogs were younger, lighter and less likely to be neutered than mesocephalic, dolichocephalic and crossbred dogs. Brachycephalic differed to non-brachycephalic types in their odds for 10/30 (33.33%) common disorders. Of these, brachycephalic types were predisposed for eight disorders and were protected for two disorders. Univariable and multivariable analyses generated differing inference for 11/30 (30.67%) disorders. This study provides strong evidence that brachycephalic breeds are generally less healthy than their non-brachycephalic counterparts. Results from studies that report only univariable methods should be treated with extreme caution due to potential confounding effects that have not been accounted for during univariable study design or analysis.
... Labrador Retriever (Lab) is a traditional waterdog in Newfoundland. During the latter half of the nineteenth century, British breeders had refined and standardized Labs that had become a popular breed because they were famously friendly and exuberant around the world [5][6][7]. Many Labs play an important role such as sniffer dogs or guide dogs in many countries. ...
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Labs as guide dogs or sniffer dogs in usage have been introduced into China for more than 20 years. These two types of working dogs own blunt or acute olfactory senses, which have been obtained by artificial selection in relatively closed populations. In order to attain stable olfactory attributes and meet use-oriented demands, Chinese breeders keep doing the same artificial selection. Though olfactory behavior is canine genetic behavior, genotypes of OR genes formed by breeding schemes are largely unknown. Here, we characterized 26 SNPs, 2 deletions, and 2 insertions of 7 OR genes between sniffer dogs and guide dogs in order to find out the candidate alleles associated with working specific traits. The results showed that there were candidate functional SNP alleles in one locus that had statistically severely significant differences between the two subpopulations. Furthermore, the levels of polymorphism were not high in all loci and linkage disequilibrium only happened within one OR gene. Hardy–Weinberg equilibrium (HWE) tests showed that there was a higher ratio not in HWE and lower FST within the two working dog populations. We conclude that artificial selection in working capacities has acted on SNP alleles of OR genes in a dog breed and driven the evolution in compliance with people’s intentions though the changes are limited in decades of strategic breeding.
... This is of particular importance at the current time given that a recent nationally representative study suggests that one in five households acquired a new pet during the COVID-19 pandemic (13%). Moreover, "designer breeds" (e.g., Labradoodles), some of which require more intensive at-home and professional grooming for coat maintenance, are increasing in popularity (17)(18)(19)(20). To advance this understudied area of animal welfare research, the goal of this paper is 2-fold. ...
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Grooming is an essential health maintenance activity that is fundamental to the welfare of many companion animals. Despite the potentially serious consequences of inadequate grooming for pets and their caregivers, few studies have examined the role of access to pet grooming services and supplies in promoting and maintaining companion animal health and welfare. The goal of this paper was two-fold: 1) To provide preliminary findings demonstrating the scope of grooming and matting concerns among animals served by a large, non-profit animal welfare organization and 2) to provide a call for research to guide effective prevention of and responses to grooming-related omissions of care. We retrospectively extracted data from five American Society for the Prevention of Cruelty to Animals (ASPCA) programs serving the New York City area: ASPCA Animal Hospital (AAH), Community Medicine (CM), One ASPCA Fund, ASPCA-NYPD (New York City Police Department) Partnership, and the Community Engagement (CE) Program. The prevalence of grooming–related concerns was relatively consistent across all three veterinary service programs (AAH: 6%; CM: 4%; One ASPCA Fund: 6%). Thirteen percent of the ASPCA-NYPD Partnership’s cruelty cases involved general hair matting concerns and/or strangulating hair mat wounds (93% were long-haired dog breed types). Five percent of CE cases received grooming-related supplies to support pet caregivers’ in-home grooming capabilities. Our findings underscore the need to understand the scope of grooming-related concerns among animals served by veterinarians and other community programs to improve animals’ access to health-related services.
... The C-BARQ is designed to provide information on dog behaviour problems by measuring 14 traits (Stranger-directed aggression; Owner-directed aggression; Dog-directed aggression; Dog rivalry; Stranger-directed fear; Non-social fear; Dog-directed fear; Separation-related behaviour; Attachment and attention-seeking; Trainability; Chasing; Excitability; Touch sensitivity; Energy level) [10]. The C-BARQ database contains over 50,000 dog behaviour records and has been collecting data since 2005 [12]. ...
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Working dog organisations regularly assess the behaviour of puppies to monitor progression. Here, we tested the predictive validity (for predicting success in guide dog training) of a shortened version of a previously developed juvenile dog behaviour questionnaire (the refined puppy walker questionnaire, r-PWQ) and compared it with the Canine Behavioral Assessment and Research Questionnaire (C-BARQ). The r-PWQ is used by Guide Dogs UK, whereas the C-BARQ was designed for pet dogs and is used by some other guide dog schools internationally. A cohort of dogs aged eight months (n = 359) were scored concurrently on the r-PWQ and C-BARQ. Analogous traits between the questionnaires were evaluated for internal consistency and association with training outcome and compared for concurrent validity. The r-PWQ was associated with training outcome for five scales (r-Excitability, Trainability, Animal Chase, r-Attachment and attention seeking and Distractibility) and the C-BARQ for two scales (Excitability and Separation-related behaviour). There were significant correlations between analogous C-BARQ and r-PWQ trait scores (p < 0.001) except for Separation-related behaviour and questionnaire scales had similar internal consistencies. The r-PWQ may be more suitable to use with guide dog schools. However, due to the correlation between analogous scales (except for “Distractibility”) some scales could be substituted for one another when reviewing the behaviour of dogs between guide dog schools using different questionnaires.
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“Designer dogs”, which are the hybrid offspring that result from intentionally breeding dogs belonging to different breeds, are an extremely popular pet choice in the United States. Poodle mixes, often called “doodles”, are a very common type of designer dog. However, there are many misconceptions surrounding them, and the reality of owning one may not match the owner’s expectations. For instance, many people believe these dogs to be non-shedding and hypoallergenic, although this is not always the case. This study explored whether the reality of owning a doodle matches owner expectations. For comparison purposes, we also asked owners of non-doodle dogs about their expectations versus reality. Our survey-based study included 2191 owners of doodles and non-doodle dogs recruited via groups of dog owners on Facebook and Reddit. The data showed that, when selecting their dogs, doodle owners were more influenced than non-doodle owners by their dog’s appearance and by the perception that doodles are good with children and are generally healthy. Doodle owners reported being highly satisfied with their dogs; nevertheless, more than twice as many doodle owners than owners of the other groups of dogs reported that their dog’s maintenance requirements, such as their need for regular grooming, were more intensive than they had expected. This finding suggests that those interested in owning doodles would benefit from having more information about their dog’s grooming needs so they can decide whether they have the time and money required to meet their dog’s welfare needs.
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Objectives To utilise a large histopathology database to ascertain the incidence and nature of skin masses in young dogs from 0 to 12 months of age. Materials and Methods A total of 2554 submissions received for histopathology from dogs 0 to 12 months of age, clinically diagnosed with a skin mass between 2006 and 2013, were retrieved from the database of a large commercial diagnostic laboratory. The histological diagnosis and site of the lesion, together with age, breed and sex of the dog were recorded. Results The most common skin mass found in this study was histiocytoma (n=2212, 86.6%). The majority of all submissions were neoplastic (n=2408, 94.3%), and most of those were benign (n=2372, 98.5%). Almost all of the benign neoplastic lesions were of round cell origin (n=2229, 94.0%) whereas most of the non-neoplastic lesions were derived from the epithelium (n=136, 93.8%). The five most commonly diagnosed skin masses in young dogs were histiocytoma, papilloma, dermoid cyst, follicular cyst and mast cell tumour. A male predisposition was shown for histiocytoma (odds ratio 1.72) and mast cell tumour (odds ratio 2.18) with a strong site predilection for the limb region (30.8% and 27.8% respectively). Dermoid cysts and follicular cysts were most commonly found in the skin of the abdomen (64.7% and 52.3% respectively) with boxers being predisposed (25.9% of dermoid cyst and 25.0% of follicular cyst). Clinical Significance A large proportion of skin mass submissions in young dogs were neoplastic and benign. Also, the most common skin mass in young dogs was found to be histiocytoma. Tumours can occur in this age group and should be considered as a potential differential diagnosis also in young patients presenting with a skin mass.
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Behavioral traits like aggression, anxiety, and trainability differ significantly across dog breeds and are highly heritable. However, the neural bases of these differences are unknown. Here we analyzed structural MRI scans of 62 dogs in relation to breed-average scores for the 14 major dimensions in the Canine Behavioral Assessment and Research Questionnaire, a well-validated measure of canine temperament. Several behavior categories showed significant relationships with morphologically covarying gray matter networks and regional volume changes. Networks involved in social processing and the flight-or-fight response were associated with stranger-directed fear and aggression, putatively the main behaviors under selection pressure during wolf-to-dog domestication. Trainability was significantly associated with expansion in broad regions of cortex, while fear, aggression, and other “problem” behaviors were associated with expansion in distributed subcortical regions. These results closely overlapped with regional volume changes with total brain size, in striking correspondence with models of developmental constraint on brain evolution. This suggests that the established link between dog body size and behavior is due at least in part to disproportionate enlargement of later-developing regions in larger brained dogs. We discuss how this may explain the known correlation of increasing reactivity with decreasing body size in dogs.
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Abnormal repetitive behaviors often pose problems for dog owners. Such behaviors are considered undesirable if they pose a nuisance or a danger to humans. Ancient dog breeds are intelligent, sociable, active, boisterous and need regular outdoor exercise, but are also independent and reluctant to follow commands. This study aimed to identify factors (breed, sex, origin, housing conditions) and situations that contribute to undesirable behaviors, such as aggression towards humans and other dogs/animals, separation anxiety, excessive vocalization, and oral and locomotion behaviors in Akita, Alaskan Malamute, Basenji, Samoyed and Siberian husky. Undesirable behaviors in dogs were analyzed based on the results of 897 questionnaires. Breed influenced aggressive behavior towards other dogs/animals, aggression towards humans, undesirable oral and locomotion behaviors, and excessive vocalization. Aggressive behaviors were more prevalent in females than in males. Housing conditions were linked with aggression towards other dogs/animals, aggression at mealtime, and excessive vocalization. Undesirable behaviors were most frequently reported in Akitas, Siberian huskies and Samoyeds, and they were more prevalent in males than in females and dogs living indoors with or without access to a backyard. Aggressive behaviors towards other dogs and animals, excessive vocalization and undesirable motor activities posed the greatest problems in ancient dog breeds.
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Studies about the behaviours of mixed-breed dogs are rare, although mixed-breeds represent the majority of the world’s dog population. We have conducted two surveys to investigate the behavioural, demographic, and dog keeping differences between purebred and mixed-breed companion dogs. Questionnaire data were collected on a large sample of dogs living in Germany (N = 7,700 purebred dogs representing more than 200 breeds, and N = 7,691 mixed-breeds). We found that according to their owners, mixed-breeds were (1) less calm, (2) less sociable toward other dogs, and (3) showed more problematic behaviour than purebreds (p < 0.001 for all). Mixed-breeds and purebreds were similar in trainability and boldness scores. However, twelve out of 20 demographic and dog keeping factors differed between purebred and mixed-breed dogs, and two factors showed considerable (> 10%) differences: neutering was more frequent among mixed-breeds, and they were acquired at older ages than purebreds (p < 0.001 for both), which could result in the observed behaviour differences. After controlling for the distribution of the demographic and dog keeping factors, we found that mixed-breeds were (1) more trainable than purebreds, (2) less calm, and (3) showed more problematic behaviour than purebreds (p < 0.001 for all). We discuss that these differences at least partly might be due to selective forces. Our results suggest that instead of being the “average” dogs, mixed-breeds represent a special group with characteristic behavioural traits.
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Background Fear/anxiety and anger/aggression greatly influence health, quality of life and social interactions. They are a huge burden to wellbeing, and personal and public economics. However, while much is known about the physiology and neuroanatomy of such emotions, little is known about their genetics – most importantly, why some individuals are more susceptible to pathology under stress. ResultsWe conducted genomewide association (GWA) mapping of breed stereotypes for many fear and aggression traits across several hundred dogs from diverse breeds. We confirmed those findings using GWA in a second cohort of partially overlapping breeds. Lastly, we used the validated loci to create a model that effectively predicted fear and aggression stereotypes in a third group of dog breeds that were not involved in the mapping studies. We found that i) known IGF1 and HMGA2 loci variants for small body size are associated with separation anxiety, touch-sensitivity, owner directed aggression and dog rivalry; and ii) two loci, between GNAT3 and CD36 on chr18, and near IGSF1 on chrX, are associated with several traits, including touch-sensitivity, non-social fear, and fear and aggression that are directed toward unfamiliar dogs and humans. All four genome loci are among the most highly evolutionarily-selected in dogs, and each of those was previously shown to be associated with morphological traits. We propose that the IGF1 and HMGA2 loci are candidates for identical variation being associated with both behavior and morphology. In contrast, we show that the GNAT3-CD36 locus has distinct variants for behavior and morphology. The chrX region is a special case due to its extensive linkage disequilibrium (LD). Our evidence strongly suggests that sociability (which we propose is associated with HS6ST2) and fear/aggression are two distinct GWA loci within this LD block on chrX, but there is almost perfect LD between the peaks for fear/aggression and animal size. Conclusions We have mapped many canine fear and aggression traits to single haplotypes at the GNAT3-CD36 and IGSF1 loci. CD36 is widely expressed, but areas of the amygdala and hypothalamus are among the brain regions with highest enrichment; and CD36-knockout mice are known to have significantly increased anxiety and aggression. Both of the other genes have very high tissue-specificity and are very abundantly expressed in brain regions that comprise the core anatomy of fear and aggression – the amygdala to hypothalamic-pituitary-adrenal (HPA) axis. We propose that reduced-fear variants at these loci may have been involved in the domestication process.
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Domestic dogs display an extraordinary level of phenotypic diversity in morphology and behavior. Furthermore, due to breeding practices introduced during the nineteenth century, these phenotypic traits have become relatively 'fixed' within breeds, allowing biologists to obtain unique insights regarding the genetic bases of behavioral diversity, and the effects of domestication and artificial selection on temperament. Here we explore differences in behavior among the 30 most popular dog breeds registered with the American Kennel Club based on owner responses to a standardized and validated behavioral questionnaire (C-BARQ). The findings indicate that some breed-associated temperament traits (e.g. fear/anxiety) may be linked to specific gene mutations, while others may represent more general behavioral legacies of 'ancient' ancestry, physical deformity, and/or human selection for specific functional abilities. They also suggest that previous efforts to relate dog breed popularity to behavior may have failed due to the confounding effects of body size.
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Dogs offer unique opportunities to study correlations between morphology and behavior because skull shapes and body shape are so diverse among breeds. Several studies have shown relationships between canine cephalic index (CI: the ratio of skull width to skull length) and neural architecture. Data on the CI of adult, show-quality dogs (six males and six females) were sourced in Australia along with existing data on the breeds' height, bodyweight and related to data on 36 behavioral traits of companion dogs (n = 8,301) of various common breeds (n = 49) collected internationally using the Canine Behavioral Assessment and Research Questionnaire (C-BARQ). Stepwise backward elimination regressions revealed that, across the breeds, 33 behavioral traits all but one of which are undesirable in companion animals correlated with either height alone (n = 14), bodyweight alone (n = 5), CI alone (n = 3), bodyweight-and-skull shape combined (n = 2), height-and-skull shape combined (n = 3) or height-and-bodyweight combined (n = 6). For example, breed average height showed strongly significant inverse relationships (p
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Evidence from other species justifies the hypotheses that useful hybrid vigour occurs in dogs and that it can be exploited for improved health, welfare and fitness for purpose. Unfortunately, most of the relevant published canine studies do not provide estimates of actual hybrid vigour because of inadequate specification of the parentage of mixed-bred dogs. To our knowledge, only three published studies have shed any light on actual hybrid vigour in dogs. There are two reports of actual hybrid vigour between Labrador and Golden retrievers, the first ranging from +2.5% to −6.0% for components of a standardised applied-stimulus behavioural test, and the second being at least +12.4% for chance of graduating as a guide dog. The third study provides a minimum estimate of negative actual hybrid vigour: crossbreds between Labrador retrievers and poodles had a higher prevalence of multifocal retinal dysplasia than the average prevalence in their purebred parent breeds. The lack of estimates of actual hybrid vigour can be overcome by including the exact nature of the cross (e.g. F1, F2 or backcross) and their purebred parental breeds in the specification of mixed-bred dogs. Even if only F1 crossbreds can be categorised, this change would enable researchers to conduct substantial investigations to determine whether hybrid vigour has any utility for dog breeding.
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Behavioural signs of fear or anxiety on exposure to noises in owned domestic dogs have been suggested in clinical studies to be common and a significant welfare concern. In this study two approaches were taken to investigate the occurrence of, and risk factors for, these behaviours: a postal survey of dog owners to investigate general demographic factors (n = 3897), and a structured interview of a sub-set of owners to gather more detailed information (n = 383). Almost half of owners in the structured interview reported that their dog showed at least one behavioural sign typical of fear when exposed to noises, even though only a quarter had reported their dog as ‘fearful’ in the general survey. This difference indicates that even where owners recognise behavioural responses to noises, they may not interpret these as associated with altered subjective state in their dog. The difference in reported prevalence between the studies highlights the importance of methodological approach in owner questionnaire studies investigating behavioural signs.
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This study used The Canine Behavioral Assessment and Research Questionnaire (C-BARQ) and regression models to explore the relative importance of dog and owner characteristics, living environment and owner–dog interaction to household dogs’ aggressiveness towards strangers, owners and other dogs. Exploratory factor analysis revealed 10 interpretable factors from the Chinese translation of C-BARQ: stranger-directed aggression, owner-directed aggression, dog-directed aggression, social fear, nonsocial fear, separation-related behavior, attachment or attention-seeking behavior, trainability, excitability and pain sensitivity. The factor structure of our study largely resembled that reported in Hsu and Serpell (2003) and van den Berg et al. (2006; Dutch translation of C-BARQ). All factors of the translated C-BARQ have adequate reliability (Cronbach α: 0.74–0.93) and are thus suitable for measuring temperament traits in Taiwan's pet dogs. Intrinsic and environmental variables important to the three aggression subscales were not entirely the same, but breed (P≤0.020) and physical punishment (P≤0.053) had significant relationships with all of them. Golden Retriever scored the lowest while dogs subjected to physical reprimands scored significantly higher on aggression subscales. In addition, higher scores on stranger-directed aggression were associated (P≤0.027) with living in rural areas, in houses with yard space and with more household members and being acquired either as puppies or for guarding purposes. Higher scores on owner-directed aggression were associated (P≤0.040) with male and older dogs, being neutered/spayed, having female owners, fewer other dogs in the household and being kept outside the house. Higher scores on dog-directed aggression, on the other hand, were associated (P≤0.050) with living in houses with either yard space or more household members and with spending less time with owners. Stranger- and dog-directed aggression had more important intrinsic and environmental variables common to them than did owner-directed aggression, which suggests that aggression towards owners may be regulated by different mechanisms from aggression towards strangers and other dogs. Although no causal relationship between dog aggression and environmental variables can be implied from observational studies, the results of this and other studies lend support to the possibility of reducing dogs’ aggressive responses through proper management by owners.