Companion Animal Parasite Council

Giardiasis, Dogs, Cats,

& People

www.petsandparasites.org

Risk Factors for Human Infection:

Protect Your Environment

1. AccidentallyswallowingGiardiacystsfrom surfacescontaminatedwithfeces,suchas bathroomfixtures,changingtables,diaperpails,

ortoyscontaminatedwithfeces.2. Drinkingwaterfromcontaminatedsources(e.g.,

lakes,streams,shallow[lessthan50feet]orpoorlymaintainedwells).

3. Swallowingrecreationalwatercontaminatedwithcysts.Recreationalwaterincludeswaterin

swimmingpools,waterparks,hottubsorspas,fountains,lakes,rivers,springs,ponds,orstreamsthatcanbecontaminatedwithfecesorsewage.

4. Eatingcontaminateduncooked,freshproduce.5. Havingcontactwithsomeonewhoisinfected

withGiardiasis.6. ChangingdiapersofchildrenwithGiardiasis.7. TravelingtocountrieswhereGiardiasisis

commonandbeingexposedtotheparasiteasdescribedabove.

The Companion Animal Parasite Council

TheCompanionAnimalParasiteCouncil(CAPC)isanindependentcouncilofveterinariansandotherhealthcareprofessionalsestablishedtocreateguidelinesfortheoptimalcontrolofinternalandexternalparasitesthatthreatenthehealthofpetsandpeople.Itbringstogetherbroadexpertiseinparasitology,internalmedicine,humanhealthcare,publichealth,veterinarylaw,privatepracticeandassociationleadership.

For more information about how parasites may affect your pet, please visit us at www.petsandparasites.org.

©2011CompanionAnimalParasiteCouncil.Allrightsreserved.2/11

CAPC Platinum Sponsors

CAPC Gold Sponsors

Boehringer Ingelheim Vetmedica, Inc.

Merial Limited

CAPC Silver Sponsors

Intervet/Schering-PloughAnimalHealthCevaAnimalHealth,Inc.•StatSpin

VCAANTECH•VirbacAnimalHealth

CAPCGuidelinesareendorsedby:

www.HeartwormSociety.org

Cystspassedindogorcatfecesarethesourceofenvi-ronmentalcontamination,andthesecystscanremaininfectiveforweeks,andevenlongerwhentheyareinwater.Forthisreason,thebestmeansofstooldisposalisingarbagethatgoestoalandfillorisincinerated.Removingyourpet’sfecesfromtheenvironmentwillsignificantlyreducetheriskoftransmission.

•Putdogorcatfecesinplasticbagsfordisposal.•Removedogandfecesfromyouryardand follow“pooper-scooper”laws.

FollowingtheseguidelineswillhelppreventinfectionswithGiardiaandmostoftheotherparasitesofpetsthatareshedinfeces.

Symptoms of InfectionIndogsandcats,infectionwithGiardiaisusuallyasymptomatic.Somepetswill,however,developpersistentdiarrhea.Thereisusuallynobloodinthestool.

Inpeople,infectionwithGiardiaalsoisoftenasymptomatic.However,somepeoplecandevelopacute,intermittent,orchronicnonbloodydiarrhea.Othersymptomsinpeopleincludeabdominalcramping,nausea,vomiting,lossofappetite,andweightloss.

How Do Dogs, Cats, and People Become Infected?

People and pets rarely share each other’s Giardia

PeoplearetypicallyinfectedwithahumanformofGiardia,dogswithacanineform,catswithafelineform,andcattleandsheepwitharuminantform.Peopleareoccasionallyinfectedwithadifferentformthatissharedwithanimals.Onrareoccasionsdogsandcatshavebeenfoundin-fectedwiththehumanform.Thus,thereislittleevidencefordirecttransmissionfrompetdogsandcatstopeople.However,therareoccurrenceofthehumanformsincatsanddogsmeansthattheremaybeaslightchancethattheyposeariskasasourceofhumaninfection.

Tobeabletodistinguishthespecificforms,theveterinarianisrequiredtosubmitsamplesforspecializedtests.

Giardia duodenalisGiardiaisatinyparasitethatlivesintheintestinesofvariousanimals.

Giardiaispassedinthefecesofanimalsintheformofacystthatisresistanttomanyenvironmentalextremes.Thesecystsarescatteredthroughtheenvironmentinfecesorfecal-contaminatedwater.Thesecystsareinfectiouswhenpassed,anduponingestionbythenexthost,theencystedtrophozoitesemergefromthecystsintheintestinaltract.Withintheintestine,thetrophozoitesfeedandmultiply.Sometrophozoiteswillthenformacystwallaroundthemselves,andthosecystswillbepassedinthefecestocontinuethecycle.

Giardia Cyst Trophozoite

Prevention and Treatment

• Unlikeforheartwormdisease,therearenodrugsthatcanberoutinelygiventoapetthatwillpreventinfection.

• Dogs,cats,andpeoplethathavesymptomsoftheinfectioncanbetreated;however,therearesituationswhereitisdifficulttoclearananimalitsinfection.

• Thereareapproveddrugsfortreatingtheinfectioninpeople.Thesedrugshavenotbeenapprovedforthisspecificuseindogsandcats,buttheseandsimilardrugsareusedinthem.