Haplorchis spp

From Dog
Adult H. pumilio [1]

Haplorchis spp are a parasitic trematode of dogs throughout South-east Asia[2].

Species which are pathogenic to dogs include:

  • Haplorchis pumilio
  • Haqplorchis taichui
  • Haplorchis yokogawai[3]

The life cycle of this parasite includes snails as first intermediate snail hosts and fish as second intermediate host. Dogs become infected from drinking contaminated water sources or eating raw or poorly cooked fish that contain encysted metacercariae[4].

In dogs, the adult fluke normally reside in the lower jejunum, where it shed eggs that are passed in the feces[5].

Diagnosis is based on coprological identification of eggs, although ELISA tests are available for experimental purposes[6].

Co-infection with other intestinal flukes such as Stellantchasmus spp, Stictodora spp and Centrocestus spp is common.

Treatment of this parasite in dogs is relatively effective with praziquantel.


  1. CDC
  2. Nguyen TL et al (2009) Prevalence and risks for fishborne zoonotic trematode infections in domestic animals in a highly endemic area of North Vietnam. Acta Trop 112(2):198-203
  3. Chi TT et al (2008) Prevalence of zoonotic trematodes in fish from a Vietnamese fish-farming community. J Parasitol 94(2):423-428
  4. Yamamoto N et al (2009) Prevalence of intestinal canine and feline parasites in Saitama Prefecture, Japan. Kansenshogaku Zasshi 83(3):223-228
  5. Nissen S et al (2012) Experimental infection with the small intestinal trematode, Haplorchis pumilio, in young dogs. Vet Parasitol Aug 15
  6. El-Seify MA et al (2012) ELISA and some biochemical tests of heterophyidae infection in laboratory animals. Parasitol Res 110(2):679-687