Feet And Leg Problems In Dairy Cattle

http://edis.ifas.ufl.edu/ ( Publisher's URL )
MISSING IMAGE

Material Information

Title:
Feet And Leg Problems In Dairy Cattle
Physical Description:
Fact sheet
Creator:
Shearer, J.K.
Publisher:
University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS
Place of Publication:
Gainesville, Fla.
Publication Date:

Notes

Acquisition:
Collected for University of Florida's Institutional Repository by the UFIR Self-Submittal tool. Submitted by Melanie Mercer.
Publication Status:
Published
General Note:
"published September, 1992,"
General Note:
"DS 68"

Record Information

Source Institution:
University of Florida Institutional Repository
Holding Location:
University of Florida
Rights Management:
All rights reserved by the submitter.
System ID:
IR00004733:00001


This item is only available as the following downloads:


Full Text

PAGE 1

FeetandLegProblemsinDairyCattle1 TheInstituteofFoodandAgriculturalSciencesisanEqualOpportunity/AffirmativeActionEmployerauthorizedtoprovideresearch,educational informationandotherservicesonlytoindividualsandinstitutionsthatfunctionwithoutregardtorace,color,sex,ornationalorigin. FloridaCooperativeExtensionService/InstituteofFoodandAgriculturalSciences/UniversityofFlorida/JohnT.Woeste,DeanJ.K.Shearer,RussGiesy2Lamenessisaproblemofincreasingimportance toFloridadairymen.Thisisinpartdueto constraintsimposedbyenvironmentalregulationand modificationstoreduceenvironmentalstresswhich requireconfinementofcowstosmallerareasfor longerperiodsoftime.Thetrendtoward confinementhousinghasresultedinanumberof changesincluding:1)confinementofcowstoharder, wetter,moreabrasive,and/orinsomeinstances slipperierfloors;2)decreasedopportunityfor exercise;and3)rationscontainingmoreconcentrates andlessroughage.Thesefactors,eitheraloneorin combination,contributetoanincreaseintherateof hoofwear,greaterpotentialformetabolic dysfunction,andahigherincidenceoffeetandleg injuryordisease. Aproperunderstandingoflamenessconditionsin termsofwhattheyare,howorwhytheyoccur,and whattodoaboutthemisessentialtominimize productionlossesaswellasthelossofcowsfrom theseandrelatedproblems.Inthefollowing,the incidenceoffeetandlegproblemsisreviewed,which includesconsiderationofthosefactorswhich influenceitsprevalence.Acasereportofaherd lamenessproblemalsoispresented.Thefinalsection discussessomeofthemorecommoncauses, treatment,control,andpreventionoflameness conditionsindairycattle.INCIDENCEOFFEETANDLEGLAMENESSSpecificinformationconcerningtheincidenceof footdiseasesincattleintheUnitedStatesislimited; however,itisbelievedtobesimilartothatreported fromtheUnitedKingdom.Onesuchsurveyof48 veterinarypracticesinvolving1821herdsfoundthat theaverageannualincidenceoflamenessrequiring treatmentbyaveterinarianwas5.6%ofcows.Of these,88%involvedthefoot.Themajorityoffoot lesions(84%)involvedthehindfeetwith85% occurringintheouterclaw.Footlesions,inorderof descendingoccurrence,werelistedas:footrot (16.3%);whitelineabscesses(15.6%);soleulcers (13.6%);puncturedsolewithpus(10.4%),and underrunheel(8.7%).Upperleglamenessaccounted fortheremaining12%oftreatedlamenessconditions, with76%oftheseassociatedwiththehindlimbs. Themostcommoncauseofupperleglamenesswas trauma.Twoothersurveyshavereportedaverage incidencesoftreatedlamenessat6.3%and7.3% annually.Whereas,theveterinariangenerallysees onlytheworstcasestheactualrateislikelymuch higher. Specificinformationrelativetolamenesson Floridadairieswasaccumulatedfroma1987study whichcomparedfootlesionsfrom14midwestern dairyherds(1492cows)withfootlesionsfrom8 Floridaherds(720cows).Evidenceoffootdisease wasmonitoredandscoredonallcowspresentedfor hooftrimming.Resultsindicatedthattheincidence andtendencytowardlaminitiswassignificantly greaterinFloridadairycattle.Ontheotherhand, footrotandinterdigitalfibroma(korns)wereless commonlyaprobleminFloridacomparedto midwesterndairyherds.Thesedatasupportthe clinicalimpressionsofmanyinFloridaandsuggest theneedforcontinuedemphasisontheestablishment ofproperfeeding,housing,andmanagement practices. 1.ThisdocumentisFactSheetDS68oftheDairyProductionGuide,publishedSeptember,1992,FloridaCooperativeExtensionService.For moreinformation,contactyourcountyCooperativeExtensionServiceoffice. 2.AssociateProfessor,CollegeofVeterinaryMedicine;Ext.AgentI,HillsboroughCounty,CooperativeExtensionService,InstituteofFoodand AgriculturalSciences,UniversityofFlorida,Gainesville.

PAGE 2

FeetandLegProblemsinDairyCattle Page2CaseReport:SevereLaminitisOutbreak onaFloridaDairyDuringthesummerof1990aseriousoutbreakof laminitisresultedintremendousfinanciallossandthe prematurecullingofmorethan100cows.Peaklosses associatedwithreducedproductivity,increasedlabor expense,drugandveterinarycosts,andcullingwere incurredduringthemonthsofJuly,August,and September.Ofcowsculled,morethan60%werefirst lactationanimalslessthan60daysinmilk. Theclinicalsyndromevariedbutformostanimals lamenessbeganveryearlyinlactationwithsymptoms typicalofacutelaminitisasevidencedbypaininall fourfeetandanextremereluctancetostandorwalk. Someneverrecoveredfromthisstage,whereasothers improvedwithtime.Stillothersdidnotshowanyof thetypicalsignsoflaminitisbutbecameacutelylame inonefootortwofeetonly.Severalofthese progressedtomoresevereformsoffootsepsiswhich extendedtosofttissuesandjointsofthefootand fetlock.Manyofthesedidnotrecoverandultimately hadtobedestroyedorculledfromtheherd. Reviewofthefeeding,housing,andmanagement practicesuptothepointoftheoutbreakrevealed severalpotentialcontributingfactors.Themilking herdrationwasanutrientdenserationwhichin retrospectlackedsufficientfiber.Longhaywasnot availabletolactatinganimalsandtheintroductionof firstlactationheiferstothemilkingrationmaynot havebeengradualenoughtoavoidlacticacidosisand thelaminitisthatsubsequentlydeveloped.Asecond factorthatlikelyinfluencedtheproblemexperienced inthisherdwastheplacementoffirstlactation animalsonconcreteinanewlyconstructedshade barninMay,approximately1to2monthspriortothe outbreak.Thecombinedeffectsofthehigh concentratetoforageratio,rapidintroductionofhigh energyfeedstuffs,andconfinementonnewconcrete arebelievedtohavebeenmajorcontributorstothe laminitisandrelatedfootproblemsthatdevelopedin thisherd.FeetandLegProblems asaCauseforCullinginFloridaLamenessisreportedtobethethirdmost commoncauseofcullingbehindreproductionand mastitis.Dependinguponthedefinitionofculling, thismaybeabitconfusing.Forexample,cowswhich leavetheherdbywayofsalefordairypurposesor thosewhichleaveduetolowproductionareremoved for"voluntary"(atthewillofthedairymen)reasons. Thosewhichleavetheherdduetoreproductive failure,diseaseandinjury,death,mastitis,ordueto feetandlegsareinvoluntarilylostfromtheherd. Sincethelossofanimalsforsuchreasonsisnotatthe discretionofthedairymentheyaretermed "involuntary."Cullingisavoluntaryprocedure appliedtoeliminatecowswithlowmilk-producing ability. Lamenessseverelylimitsmilkproductionand reproductiveperformance.Estimatesarethatcattle whichbecomelameandarenotattendedtocan experiencea20%lossinmilkproductionoveran entirelactation.Lamecowsdonotgotopasture, spendlittletimeatthefeedbunk,andprefertolie downmostofthetime.Ifthecowdoesnoteatshe cannotproducenormaintainbodyweight.Under theseconditionsshebecomesacullforreasonsoflow production.Britishsurveysindicatethatcattlesoldto slaughterasaresultoflamenesshavecarcassesworth onlyonehalfasmuchasthosesoldtoslaughterfor otherreasons.Reproductiveperformanceissimilarly reduced.Inonestudylamenessresultedin prolongationofthecalvingintervalby33days. Inthiscontext,itisnotdifficulttovisualize lamenessasanimportantunderlyingfactorin determiningacow'slongevityintheherd.DHIstate summarystatisticsfrom138Floridaherds(average herdsizeof401cows)aredisplayedinTable1. Thesedatafromthesection"YearlySummaryof CowsEnteringandLeavingtheHerd"specifythe reason(s)whycowsleftherds.Consideringallcows (alllact.)andexcludingthoseanimalssoldorculled fromtheherdforvoluntaryreasons(dairy(13),or lowproduction(45)),feetandlegproblems accountedfor6.7%(7/103)ofcowlossfromFlorida dairiesforinvoluntaryreasons(i.e.reproductive failure(36),disease/injury(25),died(21), mastitis/udder(14),andfeetandlegs(7)).TheInfluenceofGeneticFactorsin

PAGE 3

FeetandLegProblemsinDairyCattle Page3Lameness TableTable1.1.TabledisplayingdataonthenumberandreasonwhycowsleftFloridadairyherds(AdaptedfromDHIState SummaryStatistics,February,1991.) NumberofCowsLeavingtheHerd Dairy Low Prod Repro Disease Injury Died Mast/ Udder Feet/ Legs 1stlact. 6 15 11 7 6 3 3 2ndlact. 3 13 9 5 4 3 1 3rdlact. 4 17 16 13 11 8 3 Alllact. 13 45 36 25 21 14 7 -DHIStateSummaryStatisticsforFebruary1991.Geneticfactorscanpredisposeananimaltohoof problemsasabnormalitiesinfeetandleg conformationarehighlyheritable.Abnormally straighthocks,weakpasterns,sicklehocks,splaytoes, oroverlappingtoesareassociatedwithanincreasein theincidenceoflameness. Cowlegsshouldbesturdywithastrongpastern andgoodflexibilityinthehock.Theideal conformationofthecow'sfootshouldbeshort, steeplyangled,highintheheel,andevenclawed. Thesoleshouldbeslightlyconcavewiththemajority ofweightbeingdistributedoverthehoofwall.Some suggestthattheidealhoofangleis50to55degrees forfrontfeetand45to50degreesforrearfeet. Unfortunately,mostareabout43degrees.Studies haveshownreducedsurvivabilityinfirstcalfheifers withlowhoofwallangles.EnvironmentalConsiderationsThedairycowevolvedasalandanimalandnot oneadaptedtostandingonhard,abrasivesurfaces. Intoday'smodernconfinementsystemscowsspenda majorityifnotalloftheirtimeonconcrete.A furthercomplicationofconfinementhousingis restrictedexercise.Cowsjustdonothavethesame freedomtomoveaboutastheyoncedidintraditional housingsystems.Further,theiroptionsforrestingare limitedinconfinementtoafreestallorthealleyway. Consideringwhatwouldbemostnaturalforthecow itisnothardtoseewhyconfinementgenerally increasesfeetandlegproblems. Concrete,dependinguponhowitisformulated andmixed,iscapableofcreatinganextremely abrasivesurfaceforcows'hooves.Newconcreteis moreabrasivethanoldandwetconcreteisupto83% moreabrasivethandryconcrete.Studiesshowinfact thatcattlehooveswearmorethantheygrowduring thefirst2monthsonconcrete.Animalsonwet concretesufferdoubly;first,becauseoftheincreased abrasivenessassociatedwiththewetconcreteand secondly,becausewetnesssoftensthehoofhorn therebypermittinganincreasedrateofhoofwear.A furthercauseofincreasedhoofwearoccursfrom crowdingorrushingcattlewhichresultsinincreased hoofwearfromthetwistingandturningonrough abrasiveconcrete.Forthisreasondesignoffacilities whichincorporateideasforeasingcowmovement therebyreducingrotationalforcesonhoovesare importanthousingconsiderations. Smoothconcrete,ontheotherhand,reduces wearandpromoteshoofovergrowth.Itisalso slipperyandpredisposestocowinjuries,usuallyofthe upperleg,fromfalling.Groovingthesurfaceof smoothconcretefloorsincreasestractionand,while acostlyventure,iswellworththeexpensetoprevent injuriesfromfalling. Environmentalinfluenceshaveamajorimpacton feetandlegs.Cattleonconcreteforlongperiodsof timearepronetolameness.Itisbestiftheycanbe offconcreteforatleast10to12hoursperday. Grasspasturesordirtlotswhichprovidecowswitha breakfromtheconcretewillreducelameness problems.

PAGE 4

FeetandLegProblemsinDairyCattle Page4NUTRITIONANDFEEDINGMANAGEMENTNutritionandfeedingmanagementaremajor considerationswheneveraherdbeginstoexperience ahighincidenceoffootproblems,inparticular,that associatedwithlaminitis.Aprimarygoalinfeeding istomaximizedrymatterintakeinordertooptimize milkproductionyetavoidconditionswhichmightlead torumenacidosisandlaminitis.Consequently,itis afinelinebetweenwhatisbestforhealthand productionandwhatmaypredisposetoproblems. InFlorida,amajordilemmainvolvesfeeding strategiesforsummerheatstress.Duringhotweather mostdairiesattempttoincreasethenutrientdensity (increasingtheconcentratetoforageratioofdiets)of rationsasameansofmaintainingdrymatterintake rates.Initselfthiscanbetroublesomeifnot monitoredcarefully;however,inadditionitisa normaltendencyforheatstressedcattletoeatless frequently(feedingduringcoolertimesoftheday only)butmoreateachfeeding.Thecombinedeffect ofthesetypesofrationsandfeedingpatterns increasestheriskforrumenacidosisandlaminitisin hotweather.Feedlots,forexample,emphasize keepingfeedinfeedbunksatalltimesandencourage intakenumeroustimesdailyinordertoavoidrumen acidosis. Ingeneral,cowsshouldreceiveawellbalanced ration,notexceeding60%concentrateswith5to15 poundsoflong-stemmedhay.Lactatingcowsand heifersshouldbeintroducedtothemilkingherd rationgradually.Theadditionofsodiumbicarbonate inquantitiesofupto1%oftherationwillreduce rumenacidosisandmaybehelpful.Measuresto reduceheatstressandencouragefeedintake throughoutthedaywillminimizeproductionlossesas wellaslimitpotentialforlacticacidosis.HoofTrimmingWhilesomewouldliketoignoretheneedfor hooftrimming,itisanecessaryhealthmanagement procedure.Dairycowssimplywillnotproduceto theirfullpotentialunlessgiventheadvantageof regularfootcare.Further,beyondtheobvious benefitofimprovedproductivity,itisinhumane(in factirresponsible)toneglectneededtrimmingof severelyovergrownhooves.Herdsareadvisedto adoptafootcareprograminwhichhoovesare trimmedataminimumoftwiceperyear. Theavailabilityofhooftrimmingservicesvaries. Forsome,itmaybenecessarytodotheirown.In general,hoovesshouldbetrimmedinsuchmanneras toreturntheloadbearingsurfacetotheoutsidewalls ofthehoof.Bodyweightshouldbeevenlydistributed betweenclawssothatthefootandlowerleg maintainsnormalconformation.Thisreducesstress onligaments,tendons,andjoints.Whenfeethave overgrowntothepointofcausingabnormal conformation,frequenttrimmingoveraperiodof severalmonthsmaybenecessary.FootbathsTheeffectivenessoffootbathshasnotbeen thoroughlystudied.Limitedinformationsuggests somebenefitfromtheiruseinherdssuffering lamenessassociatedwithdiseasesoftheinterdigital skinandheels.Footbathsareconsideredtobeless helpfulfortreatmentofconditionsinvolvingthehoof suchaslaminitis,soleabscesses,orsoleulcers. Primaryreasonforthisisthoughttobeduetothe poorabsorptionoffootbathchemicalsbythehoof itself. Footbathsshouldbelocatedinroutesregularly travelledbycattle.Mosttendtoendupinexitlanes frommilkparlors.Sizevariesbutmostadvisethat theybeatleast30feetlongand6inchesdeep.This ensuressufficientcontacttimeandcoverage.A footbathcontainingwaterprecedingthechemicalbath isalsorecommended.Cleansingfeetinthewater bathpriortoentryintothechemicalbathextendsthe lifeofthechemicalbath.CopperSulfate-WetBathTenpercentsolutionequals16poundsin20 gallonsofwater. 1.Hotwaterwillhastendissolving.Additionof somevinegarwillaiddissolvinginhardwater. Thesolutionmustbekeptreasonablyclean sincemanurewilldeactivateit.Copper sulfateshouldnotbeallowedtocontactmetal dueitscorrosivepropertiesandbecause contactwithmetalmayinactivatethecopper sulfate. 2.Itisirritatingtothefeetandshouldnotbe usedrepeatedlyataconcentrationgreater than10%.

PAGE 5

FeetandLegProblemsinDairyCattle Page5 3.Sheepareverysensitivetoingestedcopper andwillbepoisonedbyitiftheresidueis discardedwheretheyhaveaccesstoeatit.CopperSulfate-DryBathAdd1partpowderedcoppersulfateto9parts slakedlime.FormalinFivepercentsolutionequals1gallonof36% formaldehydein19gallonswater. 1.Itisveryirritatingwheninhaledandshould onlybeusedormixedoutdoors.Itisalso irritatingtotheskinandfeetandshouldnot beusedrepeatedlyasafootbathatgreater than5%concentration.Formalintendsto hardenthehooveswithrepeateduse.Any residuesolutionshouldbediscardedanda freshbatchmixedbeforeeachuse. Otherwise,themixturemaybecometoo concentratedfromevaporation. 2.FormalinismonitoredbytheEnvironmental ProtectionAgencyunderSARATitleIIIand allsuppliersand/ordistributorsarerequired tokeeprecordsofsales.Nomorethan500 lbsshouldbekeptonsiteatanyonetime.ZincSulfateTwentypercentsolutionequals34lbspowdered, agriculturalgradezincsulfatemonohydrate(36%), per20gallonsofwater. 1.Thisisnon-irritatingtothefeetandcanbe useddaily. 2.Effectivenessforcontrollingfootproblemsin cattleislargelyunknown.SPECIFICCAUSESOF FEETANDLEGLAMENESSUpperleglamenessaccountsforonly10to15% oflamenessindairycattle.Ofthosethatoccur,most areintherearlegsandareassociatedwithinjuries associatedwithcalvingandtrauma.Specificcauses include:paralyses,fractures,dislocations,cellulitis (inflammationofthesubcutaneoussofttissues)ofthe hockjoint,andruptureofthegastrocnemiustendon.ParalysesParalysesresultfromnervedamage.Depending onseveritylamenessthatresultsmaybetemporaryor permanent.Inorderofoccurrence(frommost frequenttoleastfrequent)theyare:peroneal; obturator;radial;femoral;tibial;andsciaticnerve paralysis.Themostcommonofthese,peronealand obturator,aredescribedbelow. Peronealnerveparalysisisacommonsecondary complicationwithmilkfever,downercowsyndrome, orotherconditionwhichmaycauseacowtoremain downforanextendedperiodoftime.Theperoneal nerveinnervatestherearlegsandduetoit's anatomicallocationishighlysusceptibletodamagein the"downcow"situation.Prolongedpressureonthe lateralaspectofthestiflejoint,asoccurswhencows aredown,willcausedamagetothisnerve.Ingeneral thelongerthecowisdownthemoreseverethe potentialdamagetothisnerve.Itischaracterizedby "fetlockknuckling"intheaffectedrearleg(s).There isnospecifictreatmentandmostwillrecover spontaneouslyin1to2weeksorless.Cowliftswith shoulderandhipsupportandwidebellybandsfor uniformdistributionofthecow'sweightarehelpful. Obturatornerveparalysisoccursalmostinvariably asaresultofcalvingdifficulty.Theobturatornerve coursesthroughthebirthcanaleventuallybranching outtosupplymusclesoftheinnerrearlegs.Dueto itslocationinthebirthcanalitissubjecttodamage atcalving.Prolongedpressureasoccurswhencalves becomelodgedinthepelvisforanextendedperiodof timecreatesthepotentialfortemporaryoreven permanentparalysisasaresultofdamagetothis nerve.Severelyaffectedanimalsareunabletorise. Thosewhichareabletostandarepredisposedto "doingthesplits"orfallingasaresultofthelossof innervationtotheinnerthighmuscleswhichunder normalconditionskeepthelegsproperlyalignedand positionedforstanding.Surprisingtosomeit'snotso muchthesizeofthecalfthatcausesobturator paralysisbutthelengthoftimethatthecalfislodged withinthepelvisexposingtheobturatornerveto continuouspressureforaprolongedperiodthat resultsinparalysis.

PAGE 6

FeetandLegProblemsinDairyCattle Page6 Goodfootingisessentialtocowssuffering obturatorparalysis.Aswithotherparalysesthereis norealspecifictreatmentbeyondsupportivecare. Protectingtheseanimalsfromenvironmentalexposure (solarradiation),providingthemwithfeed,hay,and water,andoccasionalliftingand/orrepositioningis probablymostimportanttotheirrecovery.FracturesFracturesmostfrequentlyresultfromtraumatic injury.Whereas,longbonefracturesinyoung animalscanoftenbesimplyrepairedwithplaster casts,suchisgenerallynotthecaseforfracturesin largeheifersoradultcows.Instead,fracturesinadult cattleoftenleadtoslaughterofthoseaffected.A cardinalsignwithlimbfracturesisthelackofweight bearingontheaffectedleg.Animalswillcarrythe fracturedlimbandavoidbearinganyweightonit. Fracturesofthepelvisandspinearemostoften associatedwithfalls.Theytendtooccurnearcalving orduringthefirst100daysorsooflactation.The provisionofnon-slipflooringisakeyfactorin minimizingsuchproblems.DislocationsDislocationsofthecoxofemoral(hipjoint)are difficulttocorrectincows.Theycanbethecausefor moderatetoseveredisabilityandarebesthandledon acasebycasebasis.Aswithothercausesofupper leglamenessthesegenerallyresultfromtraumatic injuries.HockJointCellulitisHockjointcellulitis(swollenhocks)isoftentimes moreofacosmeticproblemthanalamenessproblem. However,wheretheincidenceishighitreflectsa problemthatmayberelatedtolackofasufficient numberofstalls,flawsinstalldesign,orcow habit/behavioralpatternsinwhichcowschoosetolie onconcreteratherthaninavailablestalls.The problemdisappearswhencowsaregivenaccessto pastureordirtlots.Lamenesscanbesevereinthose caseswheretheinfectionextendsintothehockjoint.RuptureoftheGastrocnemiusTendonRuptureofthegastrocnemiustendonisan occasionalobservationindownercows.Itcauses severedisability,andforallpracticalpurposes,isnot correctablesurgically.Examinationofdownercows shouldincludesomeassessmentofthisimportant structurebeforetreatmentisinstituted.Surprisingly, somewillbeabletostanddespiteruptureofthis tendon.Theonlyrealoptionforthesecasesis slaughteroreuthanasia.LAMENESSASSOCIATEDWITH DISEASESOFTHEFOOTThemajorityoflameness(90%)isassociatedwith diseasesofthefoot.Consequently,itistheplaceto startwhenexaminingacowforlameness.Regardless oftheimpressionthatthelesioncausinglameness maybeduetoanupperleginjury,itisabsolutely essentialtodoathoroughexaminationofthefoot. Onlyafterapossiblefootlesionhasbeenruledout shouldexaminationforanupperlegproblem proceed. Footworkishardwork.Itistime-consuming, sometimesfrustrating,andalmostalwaysfilthy. Inadequaterestraintandhandlingfacilitiesaremajor obstaclestogettingitdone.Consequently,lameness insomeoperations,regardlessofcause,istreated witha"shotofpen-strep."Iftheconditionisfootrot (whichitusuallyisnot),thisapproachmayaffecta cure.Ifnot,thedoorhasbeenopenedtomuchmore seriousproblemsthatmaynotberesolvable. Basedona1987studycomparingfootlesions observedduringtrimming,itwouldappearthatthe predominantfootproblemsinFloridadairycattleare associatedwithlaminitis.Further,thistendency towardlaminitisinFloridadairycattlewasgreater thanthatobservedformidwesterndairyherds.There arenumberofprobableexplanationsforthisfinding. Lookingtothefuture,itwillbecomeincreasingly importanttofinetuneourfeedingandmanagement practicestoavoidthisproblem. Inthefollowingwereviewsomeofthemore commonfootdiseasesofcattleemphasizing recognitionandproceduresfortreatingand preventingtheseconditions.FootrotFootrotisacontagiousdiseaseofcattle characterizedbyinflammationofthesofttissuesof thefootandsuddenlameness.Theaffectedfoot becomesseverelyswollenandthecowmayresist puttingweightonit.Thetypicallesionbeginsasa superficiallesionintheinterdigitalskin(skinbetween

PAGE 7

FeetandLegProblemsinDairyCattle Page7 thetoes)andprogressingrapidlywithtimetodeeper tissues.Thelesionhasacharacteristicfoulodor whichmaybehelpfulindifferentiatingitfromother conditions.Theincidencetendstobehigherduring thewintermonths.Confinedcattlearebelievedtobe affectedmorefrequentlythanpasturedcattle. Whenidentifiedearlytreatmentwithantibiotics (Penicillin,Oxytetracycline)isveryeffective. Treatmentshouldincludecleaningoftheinterdigital spaceandtopicaltreatmentwithKopertox(Fort DodgeLaboratories).Controlandpreventioncanbe aidedthroughtheuseoffootbathscontaining2to5% formalinor5to10%coppersulfatesolution.LaminitisLaminitis,alsoknownasfounder,isadiffuse inflammationofthecorium(sensitivetissues)ofthe hoof.Thediseaseoccursasanacute,chronic,and subclinicalcondition.AcuteLaminitisTheacuteformoflaminitisoccurssporadically. However,incidenceishighestforfirstlactation animalswithinthefirst60to90daysoflactation. Clinicalsignsincludestiffness,pain,andextreme reluctancetowalk.Someanimalswillstandwith forefeetplacedforwardwhereasothersmaystand withtheirbackarchedandfeetplacedmorebeneath them.Mostanimalswillspendthemajorityoftime lyingdown.Paincanbeexaggeratedbyforcingthe affectedanimaltorise.Redness,swelling,and tendernessabovethecoronarybandandoverthe bulbsoftheheelmaybenoticeable.Iftheanimal willpermit,onemaybeabletofeelincreasedheat throughthewallsofthehoofandoverthecoronet. Thecauses,aseludedtoearlier,arelikelyrelated togenetics,environmentalfactors,nutrition,and feedingpractices.Somehavenotedarelationship betweenlaminitisandtoxicdiseasessuchasmastitis andmetritis,orwithmetabolicdisorderssuchas ketosis(acetonemia)andrumen(lactic)acidosis. Regardlessofincitingcause,thelesioninthehoof involvesadisruptioninthemicrocirculationofblood tothenerve-richtissuesofthesensitivelaminaofthe hoof.Althoughlocalizedtheinflammationissevere andcausesextremediscomfortduringtheacute stages. Practicaltherapywouldincludetreatmentwith anti-inflammatoriessuchasBanamineoraspirinand movementoftheanimaltoagrasspasture,dirtlot, well-beddedstall,orotherareafreeofconcreteand gravelorstone.Theanimalshouldbefedhayonly andshouldbereintroducedtoconcentratefeed graduallyoverseveraldays.ChronicLaminitisClinicalsignsassociatedwiththechronicformof laminitisaremildandundetectablewiththeexception ofnoticeablehoofwallchangesthatoccurovertime. Withchroniclaminitis,hooveswiden,flatten,and developcharacteristichorizontalridges.Lesionsof thesensitivelaminaarethesameasthosedescribed fortheacuteformoflaminitis.However,theyoccur moregradually,resultinginlessobvioussignsof discomfort. Thecauseofchroniclaminitisisprimarily associatedwiththefeedingofhighgraindiets.There isnospecifictreatmentshortoffrequenthoof trimming.SubclinicalLaminitisThesubclinicalformoflaminitisrepresents possiblyoneofthemostcommonandconsequently oneofthemoresignificantformsofthisdisease.As impliedbyitsname,clinicalsignstypicaloflaminitis areabsent.Hence,itisoftenreferredtoasa syndromeassociatedwithanumberoflesionsthat occursecondarytoareductioninthestrengthand hardnessofthehoofhorn. Poorhornqualitypredisposestoanincreasedrate ofhoofwear,greaterriskofhoofinjuryandbruising, andaheightenedpotentialforbacterialinvasionof thehoof.Asaresult,lamenessduetosoleabscesses orulcersandothernon-footrotlesionsincreasesin theherd.What'smostimportantisthatone recognizewhetherornotsubclinicallaminitisisthe underlyingcause.It'squiteobviousthatemphasison treatmentoftheresultantconditionswithout correctionoftheunderlyingcause(s)onlycontributes tocontinuedandlikelyevengreatereconomicloss. Aswiththeacuteandchronicformsoflaminitis firstlactationanimalswithinthefirst60to90daysof lactationaremostsusceptible.Causesarethesame asthosedescribedfortheacuteandchronicforms.

PAGE 8

FeetandLegProblemsinDairyCattle Page8 Lesionsofthefootthataremostcharacteristicofthe subclinicallaminitisconditioninclude: 1.visiblehemorrhagesofthesolethatmay appearaspinkstainingofthehoofhornor hemorrhagesarrangedintheformof striations; 2.particularlysoft,yellowish,and/orwaxy appearinghoofhornwhichcutsreadilywith ahoofknife; 3.anincreasedincidenceoftoeulcersandsole abscessespresumablyduetosofteningofthe hooftissueandseparationofthewhiteline. Ithasbeensuggestedthatatrueproblemwith subclinicallaminitismayexistwhenevertheannual incidenceoflameness,excludingfootrot,exceeds5%. Anotherindicatorwouldbeherdrecordswhich demonstratethatover50%ofherdlamenessis occurringwithinthefirst60to90daysoflactation. Itisworthreiteratingthatwhendiscussing subclinicallaminitis,lamenessrepresentsanimportant clinicalindicatorofanadvancedproblem. Consequently,simplymonitoringlamenessisnotan effectivemeansoflimitingfinanciallossesfromfoot disease.Instead,regularhooftrimmingand evaluationandaccuratedeterminationofthecauses oflamenessisessential.Regularreviewofthe cumulativelesionsobservedattrimmingandduring thetreatmentoflamenessformsthebasisforearly recognitionofpossibleproblemswithsubclinical laminitis. Thereisnospecifictreatment;however,many recommendformalinfootbathswhichaidinhardening thehoofhorn.Preventionisaimedatavoidanceof thelactic(rumen)acidosissyndrome.Thefollowing list(bynomeansexhaustive)providesafewpractices forconsiderationwithparticularconcernforfirst lactationanimals. 1.Makefeedingchangesgradually. 2.Monitorintakeofconcentratesbyspringing heifersanddrycows(somesuggestlimiting theseanimalsto6to10lbs/hd/day). 3.Feedatotalmixedration(TMR)witha properlybalancedconcentratetoforageratio. 4.Increaseintakeofconcentratescarefully duringearlylactation. 5.Feedshouldbeavailableatalltimesand animalsshouldbeencouragedtoeat frequently. 6.Cowshousedonconcreteshouldhaveaccess todirtlotsorpastureatleast10to12hours perday.SoleAbscessesThisisoneofthemostcommoncausesof lamenessinthecow.Itischaracterizedbyacuteand severelamenessalmosttotheextentthatthecowwill refusetobearweightontheaffectedfoot.Unlike footrot,thereisnoswellingofthefoot. Soleabscessesoccurasaresultofaholeorcrack inthehornysolethatpermitstheentryof contaminants(smallsliversofstone,gravelorgrit) whichsecondarilyestablishaninfectiousprocess leadingtoabscessationbetweenthesoleofthehoof andadjacentsensitivesofttissues.Astheinfectious debris(pus)accumulates,pressurebuildsupcausing extremediscomfort.Unlessthepuspocketisdrained itwillcontinuetoenlargeandmigrateuntilitreaches asofttissueareainwhichitcanruptureanddrain. Treatmentrequiresdrainageoftheabscess,if possible,throughtheoriginalsiteofthecontaminant's entry.Theentrysitecanusuallybevisualized followingcleaningandparingofthesuperficiallayers ofthesolarhorn.Oncetheentrysiteislocated carefulparingoutofthetrackleadingtothepus pocketisrequireduntildrainageisaccomplished. Careshouldbetakentoestablishdrainage,yet minimizeperipheraldamage.Theholeestablished fordrainageoftheabscessshouldbepackedwith smallcottonballsoakedinKopertox(oriodineteat dip).Manyanimalswillshowimmediate

PAGE 9

FeetandLegProblemsinDairyCattle Page9 improvement,whereasothersinwhichabscessation wasmoreextensivemaytakeseveraldaystoimprove. Thereisnoneedforantibiotictherapyunlessthe infectionextendstodeepertissuesofthefoot. Soleabscessesareextremelypainful.Oneofthe bestwaystomediatesomeofthispainisthroughthe applicationofawoodblocktotheunaffectedclawof theaffectedfoot.Thisremovesweight-bearingonthe affectedclawbyraisingtheadjacentclaw(TechnovitDr.JorgensenLabs).Blockswilleventuallyfalloff afteraperiodofseveraldaystoacoupleofweeks.WhiteLineDiseaseThewhitelineofthesoleisanareaoffibrous connectivetissuethatjoinstherigidhoofwalltothe sole.Thesoftcompositionofthisareamakesit susceptibletopenetrationbygritorotherforeign materialthatwithtimecanmigratetothesubsolar region,abscessandcauselameness.Themost commonsiteofoccurrenceisattheheel-solejunction oftheoutsideclawsoftherearfeet.Itcanbea moreseriousproblemwhentheinfectionextendsto thenavicularbursaandassociatedtissues. Thediseaseismorecommonincattlehoused suchthattheirfeetarecontinuouslywetorasa secondaryconsequencetosubclinicallaminitis.SoleUlcersAsoleulcerisdescribedasacircumscribedloss ofthehornysolewhichexposesthecorium(sensitive tissueimmediatelybeneaththesole)ofthefoot.The typicallesionisusuallyfoundatthejunctionofthe soleandtheheel.Appearanceofthelesionwillvary accordingtoitsmaturity.Earlyulcersappearas nothingmorethanacircumscribedareaoffresh tissuethatmaybeuncoveredintheprocessofhoof trimming.Morematureorlong-standingsoleulcers maybecoveredinitiallybyrough,irregularhorn tissuethatwhenparedawayexposesgranulation tissuewhichbleedsfreelyifdamaged. Subclinicallaminitisisthoughttobeamajor causeofsoleulcers.Thesofteningofthehorntissue predisposesittoexcessivewearandmoretrauma thanwouldnormallybethecase.Heelerosion (excessivelossofheelhorntissue)leadstolossofthe normalshockabsorbingpropertiesofthisstructure. Thiscausesadditionalstrainandpressureonthe heel/solejunctionandexacerbatesdevelopmentofthe lesion. Treatmentrequiresremovalofthenecrotic(dead ordecaying)horntissuefollowedbyelevationofthe affectedclawbycementingawoodenblockonthe unaffectedclaw.Allhealthyhorntissueshouldbe leftinplace.Warts-InterdigitalPapillomatosisFootwartsareasporadicprobleminFlorida herds,butwhentheyoccurtheycanbequite troublesome.Formanyherdstheproblemarrives withthepurchaseofcattlefrominfectedherds.The lesionsoccurmostcommonlyontheareajustabove theheelsontherearfeet.Theyarealsofrequently observedonthefrontsideofthefootinthe interdigitalcleftextendingintotheinterdigitalspace betweentheclaws.Lesionsdevelopfinger-like projectionsandareextremelypainfultothecow. Consequently,mostcowswillresistexamination proceduresinvolvingtouchingormanipulationofthe wart-likemasses. Asonemightexpectaffectedcattleshow pronouncedlameness.Mostprefertolieintheir stallsrisingonlywhennecessary.Thisresultsin reducedfeedintakeandweightlosswhichcalculates toasignificantreductioninmilkyield.Onestudy reportsadecreaseinmilkproductionby20to50%in affectedanimals. Exactcauseofthediseaseisunknownbut appearstohaveaninfectiouscomponentandmaybe relatedtoenvironmentalfactors.Thecondition seemstothriveinsituationswhichpredisposeto chronicirritationoftheskinwherefeetare continuouslydirtyandwet. Treatmentvarieswithseverity.Surgicalremoval withtopicaltreatmentandbandagingisreportedto bethepreferredmethodforaffectingacure. Autogenousvaccines(vaccinesmadefromthewarts themselves)donotappeartobeeffective.Somehave claimedsuccessthroughtheuseofformalinfootbaths orfromdirectlysprayingthelesionswiththeformalin footbathsolutionateachmilking.

PAGE 10

FeetandLegProblemsinDairyCattle Page10SUMMARYFeetandlegproblemsareamajorhealthconcern andasthetrendtowardconfinementhousing continuestheincidenceoflamenesswilllikely increase.Thecausesandpredisposingfactorsare manyandinclude:nutritionandfeeding;housingand environment;concurrentdisease;managementfactors; andgeneticinfluences.Themajorityoflameness (90%)occursinthefoot.InFloridathemajorcause oflamenessappearstolaminitisandrelated conditions.Routineexaminationoflamecowsandof feetatthetimeoftrimmingcanprovidevaluable informationregardingsubclinicalfootdiseasessuchas subclinicallaminitis.Inshort,timeshavechanged. Regularfootcareandhooftrimmingisnotaluxury weprovidetothecow,itisamustifweexpectto achievemaximumproductivityandlongevityfromher. Itisinvestment-justthesameasteatdip-onlyin thiscase,theinvestmentistoinsureherabilityto walk.Thatiseverybitasimportantasinsuringgood udderhealth.