BADBEAKSAPICTORIALKeyPoint:Nomatterhowdeformedorovergrownabeakappears,italmostneverpreventsabirdfromeating.IntroductionThebeakincludesthebonesoftheupperandlowerjawsandtheirkeratinizedsheathsorrhamphotheca.Thishornycoveringfunctionallyreplacesthelipsandteeth.Thereistremendousvariationintheshapeofthebeakdependingonhowdifferentspeciesfeedandlive.Inpsittacines,theupperbeakismassiveandcurved,whereasthelowerbeakissmallandhorse‐shaped.Thisiswhyparrotsarecalledhookbills.Aparrot’sbeakisadaptedtocrackinglargenutsandseedsaswellastearingandshreddingwoodfromtreestoprovidenestsites.Itisalsousedforgrasping,climbing,preening,anddisplaying.Itcanbeaformidableweaponyetalsofunctionasadelicateutensilforfeedingnewbornchicks.Microscopically,thehornybeakresemblesskin,consistingofdermisandamodifiedepidermis.Theepidermisisverythickanditscellscontainfreecalciumphosphateandhydroxyapatitecrystals,inadditiontoabundantkeratin.Thisiswhathelpsmakethebeaksohard.Keratinisaninsolubleproteinandistheprincipalconstituentoftheepidermisinhair,nails,andthebeak.Theouterlayersofthebeakarecontinuouslybeingreplacedbynormalwearandtear.Manybirdownerserroneouslybelievethattheupperbeakgrowsfromthecereandcontinuestothetip(oredges)whereitisthenwornoff(likewisewiththelowerbeak).Onthecontrary,beaktissuegrowscontinuouslyoutward(towardsthesurface)overmuchofthebeak.Asthekeratinizedepitheliumreachesthesurface,itiseitherwornofformaymovedistallyashortdistancebeforeitislost.Onlytowardstheedgesandtipdoesthebeaktissuetrulymoverostrally.Thesurfaceofthebeakinjuvenileparrotsissmoothbecausethegrowthisnew.However,asthebirdreachesitsfirstyearandolder,thebeaktakesonamoreirregularappearance.Thisisaresultofthenormalwearingoffoftheouterkeratinlayers.Sometimestheselayersflakeofforpeel,leavingbehindledges

onthebeak’ssurface.Theseledgesarewhatmakethebeaklookroughandscaly.Theseledgescanalsobemisinterpretedascracks,whichtheyarenot.Howirregularabird’sbeakappearscanalsoberelatedtodiet.AdietlowinvitaminA(seedslackVitaminA)canleadtohyperkeratosis,whichclinicallycausesthebeaktobecomethickenedandovergrown.Suchbeakscanappearveryscaly.Thebeakcanalsoappearroughifthebirddoesnotadequatelyrubitonhardinanimateobjects,suchasalavastoneorconcreteandsandperches.Partofthephysicalexaminationofeachbirdincludesanevaluationofthebeak.Mosthealthyparrotshavebeaksinwhichthesurfaceisslightlyirregularandthetipabitlong.Suchbirdsoftenreceivea“cosmetic”beaktrim.Acosmetictrimisnotnecessaryforthehealthofthebird,butbydoingso,thebirdlooksbetter,whichinturnmakestheclientmoreappreciative.Somebirdshaveapathologicconditionwhichcanchangethenormaloutwardappearanceofthebeakandaffectsomebeakfunctions.Insuchcases“corrective”beaktrimmingisnecessary.Asidefromlosingtheentireupperorlowerbeakduetotraumaticinjury,overgrowthordeformityofthebeakrarelyaffectsabird’sabilitytoeat.Beaktrimmingisaccomplishingusingavarietyoftools,includinghumannailtrimmers,cuticlecutters,andahobbytool(Dremel).Thepreferreddremeltooliselectricandvariablespeed.Acourseconicalgrindingstone(#952)istheonlybitthisauthorusesnomatterthesizeofthepatient.Dremeltoolsandaccessorystonesareinexpensive($69and$3)andcanbepurchasedatWal‐Mart,HomeDepot,Lowe’s,andmostotherhardwarestores.Anesthesia(isofluranegas)isnotrequiredforbeaktrimming,butitsuremakesiteasierandlessstressful,bothfortheveterinarianandhisassistant,andforthebird.Oneshouldbeawarethatfullyawakebirdscanstresseasilyduringthisprocedure,especiallywhenusingadremeltool,anddeathshavebeenreported.Birdsareusuallyheldinatowel.Oneshouldalsobeverycarefulnottocompressthebirdtootightlywhichcanadverselyaffectbreathingandheartrate.Thefollowingphotographsshowvividexamplesofnormalandabnormalbeaksthatwereseenbytheauthor.

Figs1and2:Trimmingabird’sbeakduringaroutineexamination.Facemasksareworntopreventinhalationofbeakdust.Thebird’sbodyisheldwithatowelbyanassistant.Thevetsecurestheheadwithonehandandwiththeother,holdsadremeltoolwhichisusedtosmoothoutthebeaksurfaceandedges.

Figs3and4:Blue‐crownedconureshowingatypical“cosmetic”beaktrim.Inthefirstpicture,thebeaksurfaceappearsalittleroughandscalyandthetipsareabitlong.Aftertrimmingthesurfaceissmoothandtheedgescleanedupandshortened.Thebeakappearsshinnyduetotheapplicationofmineraloil.

Fig5:HYPERKERATOSISRed‐headedAmazonparrot.25+yearsoldandfedadietofseedsonly.HyperkeratosisduetolowvitaminAhascausedthickeningoftheupperbeak.Noticethetwobeaklayerstowardsthetip…theinnerlayeristhenormalone.Yellowfeathersonheadareabnormalduetomalnutrition.

Fig6and7:Red‐headedAmazonparrotwithsevereovergrowthoftheupperbeak,beforeandaftertrimming.Birdfedseeddietonly.Birdwasstillabletoeat.Noticethatthelowerbeakisnormal.Seedsarehulledusingthefrontofthelowerbeakedgeagainsttheundersideoftheupperbeak.

Fig8and9:ExamplesofbeakhyperkeratosisduetomalnutritionrelatedtoFattyLiverDiseaseinaQuakerparakeetandBlueandGoldmacaw.Bothbirdswereoverweight.Themacaw’sbeakhasbecomenecrotic.

Fig10and11:SeverebeakhyperkeratosiswithnecrosisinaSeveremacawthatwasgrosslyoverweight.Noticefattytumorsinabdominalregionofthisobesebird.

Fig12and13:TwootherexamplesofseverehyperkeratosisinaBlue‐frontedAmazonandaDoubleYellow‐headedAmazonparrot.TheYellow‐headedparrotalsohaskeratinizationontheundersideofthetongue.ThisconditionisknownasWoodyTongue.

Fig14and15:TRAUMATOTHEBEAK.Babybirdsarepronetomutilationbytheirparents.If1/3ofthebeakorlessisremoved,thebeakwillgrowbacknormally.Ifmorethan1/3ofthebeakislost,itmaylooklikethisAmazonparrot.Mateaggressioncanoccurinbreedingpairs,especiallyCockatoos.ThisfemaleUmbrellacockatoo’sbeakwasseverelydamagedbythemale.

Fig16and17:AmutilatedBlueandGoldmacaw(byparentbirdswhenthisbirdwasababy)hasresultedisaseverelydistortedscissorbeak.ThebirdmaylookUGLY,butiteatsfine…infactsheisfat!Healed,damagedupperbeakandcereinaMitredconureasaresultofanencounterwithanother,largerbird.

Fig18and19:Splitlowerbeak(rightonthemidline)inaBlue‐frontedAmazon.Thetwofreelymovablepiecescannotbereattached.Surprisinglythiscausesnoproblemwitheating.AWhite‐eyedconurewithasplitlowerbeakontheleftside.Rightlowerbeaksectionhaselongatedandrisentoalevelabovethecere.

Fig20and21:Green‐cheekedconurewho’supperbeakwascompletelybittenoffbyacockatoo.Ifthisbirdwasaseedeater,itwouldprobablynotadapttoapelleteddietintimetosurvive.Fortunatelythisbirdwasapelleteaterandhassurvivedformorethan1year.Quakerparakeetshowingpermanentscarringfromapreviousinjurynearthecere.

Fig22and23INDENTATIONOFTHELOWERBEAKinAfricanGreys.ThecauseofthisconditionwhichdevelopsinsomeadultCAG’sisunknown.Thelowerbeakelongates,whichinturncausestheupperbeaktogrowouttoreachovertheendofthelowerbeak.Aftertrimming,theindentationisclearlyvisible.

Fig24and25:SCISSORBEAKisaconditionwheretheupperbeakisbenttoonesideresultinginovergrowthofthelowerbeakontheotherside.Causesmayincludeheredity,incubationproblems,malnutrition,infection,andtrauma.Incorrectfeedingtechniquesinbabybirdshavealsobeenincriminated.

Fig26and27:SeverelyovergrownscissorbeakinaMoluccancockatoobeforeandaftertrimming.

Fig28and29:VerybadscissorbeakinaBlue‐crownedAmazonparrotbeforeandaftertrimming.Thetipofthelowerbeakwasjusttouchingtheskinoftheneck.Thiswasabreederbird…shewashavingnodifficultyeating.

Fig30and31:Grotesquescissorbeakinalovebirdsecondarytoupperrespiratoryinfectiononthebird’sleftside.Afterthescabisremoved,anerodednasalandsinuscavityremains.Activeinfectionisinremission.

Fig32and33:CRACKSinthefrontofthelowerbeakarenotuncommon,especiallyinMini‐macawsandJardines.Theyrarelyextendmorethan½inchdownwardandwillnevercausethelowerbeaktosplitinhalf.Theycanbemostlygroundoutwithadremelbyshorteningthefrontedgeofthelowerbeak.Amazonparrotwithabizarre,chronicpartiallysplitlowerbeak.

Fig34and35:INFECTIONBeakrotsecondarytoPsittacineBeakandFeatherDisease(PBFD)virusinaseverelyaffectedCockatoo.Bacterialinfection(abscess)inthenasalcavityextendingintotheupperbeakcausingswellinganddisease.

Fig36and37:CANCERSquamouscellcarcinomainvolvingthelowerbeakleadingtoovergrownoftheupperbeak.Theendoftheupperbeakhadpuncturedthroughtheskinoftheneck.Thisbirdwaseuthanized.Smallbenignskintumoroccurringatthecommissureofthebeakthatwaseasilyremoved.

Fig38and39:MANDIBULARPROGNATHISM.Acongenitalbeakdeformityoccasionallyseeninchicks,especiallycockatoos,inwhichtheupperbeakgrowsdownward,insidethelowerbeak.Correctivetrimming,applyingtractionortapesplintstostretchouttheupperbeak,anddentalacrylicprosthesesarealltreatmenttechniquesthatmaybeused.Correctivetrimmingshownhere.

Fig40and41:LOCKJAWThisGoffincockatoohasanarthriticbeakconditionwhichcausesthebonesofthejawstobecomecompletelyimmobilewhenthebeakedgescometogether.Foodgetsintothemouthonlythroughthegapeinthebeak.Trimming3xayearopensthisgapeandallowslimitedmovement.

Fig42and43:MISCELLANEOUSHarlequinmacawthatwasrescuedshowingsevereelongationoftheupperbeak.Beforeandafterpicturesofa“corrective”trim.

Fig44and45:Budgerigarinfectedwithscaly‐facemites.Notehoney‐combedencrustationsaroundeye,oncere,andedgeofbeak.Beakinvolvementcancauseseveredeformity.BlueandGoldMacawshowingsignsofallergy…pink,puffycerewithskinexcoriationaroundnaresanddriednasaldischargeonbeak.