Etiology: Tritrichomonas species (muris, minuta), Trichomitus wenyoni and Tetratrichomonas microtiare one-celled, eukaryotic organisms.

Incidence: The incidence of trichomonadinfection is common.

Transmission: Transmission is fecal-oral and occurs via ingestion of pseudocysts.

Distribution: Trichomonads are found in the cecal and colonic lumen. Tritrichomonas may retrograde into the small intestine.

Clinical Signs: No clinical signs have been attributed directly to these organisms. Diarrhea may be exacerbated by the presence of these flagellates, however their role as contributors to disease is poorly defined.


Antemortem: PCR of feces can be used to diagnose this disease.

Postmortem: Wet mounts of cecal contents reveal slow moving, flagellated protozoa with an undulating membrane. Trichomonads move with a jerky, wobbly, undirected motion. Histopathologic examination may also be used to diagnose trichomonad infection.

Diagnostic morphology: Pear- to lemon-shaped trophozoites have an undulating membrane and 3 (tri-) to 4 (tetra-) anterior flagella. There is NO true cyst form.

T. muris: 16-26 x 10-14 µm

T. wenyoni: 6-16 x 3-6 µm

T. minuta: 4-9 x 2-5 µm