Etiology: Giardia muris is a flagellated, one celled, eukaryotic organism.

Incidence: Incidence of infection is rare.

Transmission: Fecal-oral transmission via ingestion of infective cysts.

Distribution: Giardia can be found in the interior small intestine.

Clinical signs: Usually no clinical signs are observed. These protozoa may proliferate in diarrheic states; however, their role as contributors to disease is poorly defined.

Diagnosis:

Antemortem: PCR of feces can be used to detect Giardia.

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.” 8 caudally directed flagella.