Etiology: Giardia muris is a flagellated protozoan.
Incidence: The incidence of infection is rare.
Transmission: Fecal-oral transmission via ingestion of infective cysts.
Distribution: Giardia muris is found in the anterior small intestine.
Clinical signs: No clinical signs have been attributed directly to these organisms. These protozoa may proliferate in diarrheic states, however their role as contributors to disease is poorly defined.
Antemortem: PCR of feces can be used to diagnose Giardia infection antemortem. 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 8 caudally directed flagella.