Etiology: Giardia muris is a one-celled eukarytic organism.
Incidence: Infection with Giardia muris is rare.
Transmission: Fecal-oral transmission 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 (difficult).
Postmortem: Wet mounts of intestinal contents may reveal slow-moving flagellated protozoa with a “falling leaf” rolling motility. Histopathologic examination may also be used to diagnose Giardia species infection.
Diagnostic morphology: Broad, piriform trophozoite with 2 anterior nuclei that when stained with weak iodine solution gives the appearance of a “monkey face.” There are eight caudally directed flagella.