Etiology: Trichomonas species (muris, minuta, wenyoni) are one celled, eukaryotic organisms.

Incidence: Incidence of trichomonad infection is common.

Transmission:  Transmission is fecal-oral via ingestion of infective cysts.

Distribution:  Giardia muris is found in the anterior small intestine.

Clinical Signs:  Clinical signs are not usually observed. These protozoa may proliferate in diarrheic states, however their role as contributors to disease is poorly defined.


Antemortem: Fecal PCR can be used. Wet mounts of fresh fecal material or use of sucrose gradient may reveal cyst forms (this method of diagnosis is difficult).

Postmortem: Wet mounts of cecal contents reveal slow moving, flagellated protozoa with an undulating membrane. Trichomonads move with a jerky, wobbly, undirected motion.


Diagnostic morphology:  Pear- to lemon-shaped trophozoites with 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. minuta 4-9 x 2-5 µm

T. wenyoni 6-16 x 3-6 µm

Histopathologic examination may also be used to diagnose trichomonad infection.