Dipylidium caninum egg packets in wet mounts. D. caninum eggs are round to oval (average size 35 to 40 µm; range 31 to 50 µm by 27 to 48 µm) and ...SkipdirectlytositecontentSkipdirectlytopageoptionsSkipdirectlytoA-ZlinkDPDx-LaboratoryIdentificationofParasitesofPublicHealthConcernSectionNavigationCDCHomeFacebookTwitterLinkedInSyndicateDipylidiumcaninumMinusRelatedPages[Dipylidiumcaninum]ParasiteBiologyImageGalleryLaboratoryDiagnosisResourcesCausalAgentDipylidiumcaninumisacommontapewormofdogsandcats,butisoccasionallyfoundinhumans.Ithasmanycommonnamesincludingthe“fleatapeworm”,“cucumbertapeworm”,and“double-poredtapeworm”.LifeCycleViewLargerGravidproglottidsarepassedintactinthefecesoremergefromtheperianalregionofthehost.Intheenvironment,theproglottidsdisintegrateandreleaseeggpackets,whicharealsooccasionallyfoundfreeinthefeces.Theintermediatehost(mostoftenlarvalstagesofthedogorcatfleaCtenocephalidesspp.)ingestseggpackets,andtheoncospherewithinisreleasedintothelarvalflea’sintestine.Theoncospherepenetratestheintestinalwall,invadestheinsect’shemocoel(bodycavity),anddevelopsintoacysticercoid.Thecysticercoidremainsinthefleaasitmaturesfromalarvaintoanadult.Thevertebratehostbecomesinfectedbyingestingtheadultfleacontainingthecysticercoid.Inthesmallintestineofthevertebratehost,thecysticercoiddevelopsintotheadulttapewormafteraboutonemonth.Theadulttapeworms(measuringupto60cminlengthand3mminwidth)resideinthesmallintestineofthehost,wheretheyeachattachbytheirscolex.Gravid,double-poredproglottidsdetachfromthestrobila(body)andareshedinthefeces.Humansalsoacquireinfectionbyingestingthecysticercoidcontaminatedflea.Childrenaremostfrequentlyinfected,possiblyduetoclosecontactwithflea-infestedpets.HostsCanidsandfelidsarethenormalhostsforDipylidiumcaninum.Theintermediatehostisusuallythelarvalstagesofthedogorcatflea(Ctenocephalidesspp.)andoccasionallyTrichodectescanis(thedoglouse).GeographicDistributionWorldwide;thistapewormisubiquitousandcommonamongpetdogsandcats.Humaninfectionisrare,buthasbeen