Pentatrichomonas spp

From Dog
P. hominis under light microscopy[1]

Pentatrichomonas spp are a ubiquitous flagellated protozoan parasite found rarely in dogs, with prevalence rates less than 1% in some countries[2][3].

Co-infections with other intestinal protozoa are common and this parasite is not thought to be a primary initiator of disease.

Species which are pathogenic to dogs include:

  • Pentatrichomonas hominis

Infection are relatively common in dogs and result in diarrhea, although most affected dogs are asymptomatic carriers.

This parasite is one cause of canine trichomonias, including Tritrichomonas foetus, which is less frequently diagnosed[4].

Infections with other protozoa such as Giardia spp, Neospora spp[5] and Cryptosporidium spp also occur.

Diagnosis is based on coprological examination for cysts, axenic culture[6], ELISA and PCR assays[7].

Treatment is usually effective with fenbendazole, ronidazole, metronidazole or secnidazole.

As is observed with Giardia spp infections, elimination of all parasites are never 100% successful and re-emergence of infections are common, particularly in kenneled dogs[8].


  1. Kansas State Uni
  2. Yamamoto N et al (2009) Prevalence of intestinal canine and feline parasites in Saitama Prefecture, Japan. Kansenshogaku Zasshi 83(3):223-228
  3. Meloni BP et al (1993) The prevalence of Giardia and other intestinal parasites in children, dogs and cats from aboriginal communities in the Kimberley. Med J Aust 158(3):157-159
  4. Tolbert MK et al (2012) Species identification of trichomonads and associated coinfections in dogs with diarrhea and suspected trichomonosis. Vet Parasitol 187(1-2):319-322
  5. Cole RA et al (1993) Detection of Neospora caninum in tissue sections using a murine monoclonal antibody. J Vet Diagn Invest 5(4):579-584
  6. Fukushima T et al (1990) Pentatrichomonas hominis from beagle dogs--detection method, characteristics and route of infection. Jikken Dobutsu 39(2):187-192
  7. Kim YA et al (2010) PCR detection and molecular characterization of Pentatrichomonas hominis from feces of dogs with diarrhea in the Republic of Korea. Korean J Parasitol 48(1):9-13
  8. Fiechter R et al (2012) Control of Giardia infections with ronidazole and intensive hygiene management in a dog kennel. Vet Parasitol 187(1-2):93-98