1. Equine Self-Mutilation – Stallions
Introduction
Humanshave beenalteringthe behaviourof equinesforthousandsof yearsthroughthe use of specific
breedingtacticsandtrainingmethods. Howeverthere are basic,natural behavioursthatequinesexhibit
that are inherentintheirnature thatmustbe recognizedbytheirhumanhandlers. Unfortunately,when
thisrecognitionisnotforthcomingandthisbehaviourisnotaccommodated,the equine will resortto
unnatural behavioursinanefforttoseekrelief. These behavioursare oftenunacceptable totheir
handlers. Inthispaper,the stereotypy,self-mutilation,will be examined,specificallyhow itis
manifestedinstallionswhoare experiencingsexual frustration.
The Stereotypic Behaviour
One theoryof whystallionspredominatelyexhibitthisstereotypicbehaviour,istheyare motivatedto
performa naturallyoccurringbehaviour(inthiscase,courtingandsubsequentcopulation),andif that
behaviourispreventedorthwarted(throughisolation,orpreventionof breedingactions),itresultsina
chronicstate of need. Once a critical level isreached,the stallionwill performanabnormal behaviour
(self-mutilation)inan attemptto decrease hisunsatisfied need.
Self-mutilationmanifestsinavarietyof actions:
 Spinningincircles
 Buckingand kicking outwithone or bothback legs
 Nipping/bitingatflanks,shoulders,chest
 In extreme cases,the stallionwill violentlylungehisheadorbodyintoa wall/solidobjector
proceedfromstandingintolateral recumbencywithvelocity.
(McDonnell,2000)
Self-mutilative behaviourinhorsescanbe categorizedintothree differentforms:
 Extreme behavioural response tophysical discomfort.
 A more subduedbehaviour,similartothe eventof stall walkingorweaving.
 Self-directedintermaleaggression.
For the purpose of thispaper,the thirdform, self-directedintermale aggressionwill be examined.

2. The Crisis of the Natural Behaviour
In free roamingbandsof horses,the bandstallionservesseveralfunctions;he drivesthe bandfromthe
rear, protectsthe band from predationandprocreates. Whentwostallionsfromdifferentbandsmeet,
variousbehavioursare exhibited,including:investigationof the flankareas,scentingof the bodyand
nippingof the genital andflank. Thismeetingisusuallyaccompaniedwithvocalizations(squealing),
kicking,andspinningincircles. However,whenastallionisisolatedfromother“bandmembers”during
the breedingseason,thisbehavioursare turneduponhimself. Thisbehaviour,exhibitedinastate of
isolation,mayalso be heighteneduponthe investigationof studpiles, bodyoil residue leftinpaddocks
that may have beenpreviouslyusedbyanotherstallion,andscentsof maresinestrous. The
developmentof thisbehaviourislessacute thanthe otherformsand can beginas earlyas pubertyor
intothe teens. “It typicallycontinuesforthe life of the stallion.”(McDonnell,2000).
Managing Self-Directed Intermale Aggression
As withanystereotypicbehaviour,athoroughveterinariancheckup-upshouldbe firstonthe listto
determine if there isaphysical reasonforthisbehaviour. Generally,if the stallionhashadhisbehaviour
labelledasself-directedintermale aggression,anyphysical maladyhasalreadybeenacknowledgedand
ruledout.
Notall of the management tacticssuggestedbelow have successful outcomes,whatmayworkforone
stallion,maynotworkfor another. These managementtacticsare not listedinanyorderof success:
1. Pharmacologicaids-generallymedicationsare usedinconjunctionwithother management
changes,notas a stand-alone solution. Examplesof pharmacologicaidsinclude longterm
tranquilizers,tricyclicanti-depressantssuchasimipramineandclomipramine,progesterone
and 1-tryptophan.(McDonnell,2000).
2. Gelding-notalwaysa viable tacticforvaluable breedingstallions. There have beencasesin
whichthe behaviourdisappears,howeveralsosituationsinwhichthe behaviourworsens.
3. Physicalrestraint-notconsideredalongtermmanagementsolutionasitdoesnotaddress
the stereotypy,itonlypreventsfurtherinjurytothe stallionwhile optionsare being
considered. Restraintsmayinclude neckcradles,grazingmuzzles,bibsandblankets. Itis
importantto understandthatthistype of self-mutilationiscausedbyfrustration,the
stallionispreventedfromexhibitednatural behaviours,thusthisdrive hasmanifestedinto

3. an abhorrentbehaviour. Byrestrainingthe stallion,the handlerisfurtherpreventingcoping
behaviourandadditional stereotypieswill manifest.
4. Distractions (social,work,nutrition)-considered one of the mosteffectivemanagement
solutionforthisbehaviouristoprovide a distractionoran “outlet”. Oftencausedby
inappropriate management,stallionsare commonlyisolateddue totheirhighenergy
nature. By turningthe stallionoutintoa more appropriate environmentthatincludesa
large pasture and a small groupingof mares,a social distractioniscreated. Now the stallion
has purpose andresponsibility.
Howeverthismanagementpractice maynotbe feasibleforthe performance stallion. Other
social companionshipsmaybe consideredsuchasotherspecies. Examplesincludedonkeys,
goats andchickens. “…chickensasstall companionsforself-mutilators,itseemsthatthe
horse sometimesisreluctantto move aroundthe stall,lestitcause the chickentoscurry
and flutter. Some stallionsalsoseemdistractedbytheirefforttoavoidsteppingonthe
chicken.”(McDonnell,2000)
An all forages dietoftenprovidessignificantchangesinbehaviour. Asconcentratesintheir
manufacturedformisnotpart of a natural equine diet,there have beenindicationsthat
excessiveconcentratesproduce alteredbrainfunction. Alteredbrainfunctionshave been
identifiedaskeycomponentsinthe developmentof stereotypicbehaviours.
There are othermanagementtacticsthatbearmentionaswell. Oftenself-directedintermale
aggressionsessionsare provokedbythe presence of otherstallionscentsandfeces. Simplesolutions
such as applyingascentmaskerto the nose, frequentbathingandremoval of fecesfromthe livingareas
may be used.
Anothermanagementtacticthathas experiencedextensivesuccessinrehabilitatingstallionswhoare
self-mutilatingishousingthe stallioninatie stall. Currentlythere are nostudiesonthe use of tie-stalls
and thisstereotypy,however“….recentworkwithtie-stalledhorsesinthe PMUindustryhasindicated
that abnormal behaviouringeneral isverylow intie-stalledhorsescomparedtobox stalledhorses”.
(McDonnell,2000).
It’simportantto reiterate thatitmay take careful applicationof several of these tacticstoproduce a
desiredresult. Itmay take a combinationof tacticsor one simple change. Stallionsare individualsand
each will responddifferentlytothe above mentionedmanagementchanges.

4. Conclusion
The science behindall three formsof self-mutilationisnota well-knownone. Itpresentsanespecially
complicated scenarioasthe behaviourmaybe causedbyphysical orpsychological issues. There isno
effective,concrete cure forself-directedintermale aggressive self-mutilation.Instead,itissuggested
that managementof stallionbe examined,changesmade,andcurrent,on-goingcare be administeredto
lessenthe chance of potential seriousinjury.

5. References:
McDonnell,Sue,PhD.March 1, 2000. “Equine Self Mutilation”. Accessedat: www.thehorse.com/print-
article/12622. Accessedon:March 8, 2015.
McDonnell,Sue,PhD. 1999. “StallionSexualBehaviour”. Accessedat:
research.vet.upenn.edu/Portals/49/00StalliU.pdf. AccessedonMarch11, 2015.
Sappington,Brenda,PhD.2001. “Hormonesand Horse Behaviour”.Accessedat:
http://www.horsechannel.com/horse-breeds/hormone-horse-behavior-1168.aspx. Accessedon:March
15, 2015.
Shuster,Louis,PhD.etal. 2007. “Pharmacological Treatmentof Equine SelfMutilationSyndrome”.
Accessedat:www.jarvm.com/articles/Vol2Iss2/DODMANJARVMVol2No2.pdf. AccessedonMarch 10,
2015.