WAcanthocephalus (animal)
WAncylostomatidae
WAnisakidae
WAscaridida
WAscarididae
WAscaridina
WBivalvulida
WCapillaria (nematode)
WCaryophyllidea
WCeratomyxidae
WCestodaria
WCobboldia
WCyclophyllidea
WEchinorhynchida
WEoacanthocephala
WErgasilus
WGnathiidae
WGongylonema
WHelminthology
WHenneguya zschokkei
WHeterophyes
WHeterophyidae
WHuffmanela filamentosa
WHyalomma
WHyalomma dromedarii
WMetagonimus
WMultivalvulida
WMyxobolus
WNematode infection
WNeoandracantha
WNeoechinorhynchida
WNomadinae
WOnchocerca
WOnchocerca tubingensis
WOrnithodoros
WOrnithomyinae
WOrnithonyssus
WOtobius
WOxyurida
WOxyuridae
WPalaeacanthocephala
WPlerocercoid
WPolymorphida
WPraobdellidae
WPsilostomatidae
WRhabditia
WRicinus (insect)
WSpiruria
WStephanostomum baccatum
WTelosentis exiguus
WTick dragging
WTrichinellidae
WTrichuridae
WZoogonidae