Often, the examining veterinarian will perform a special fecal flotation test that is likely to damage to the cysts or trophozoites less, or a direct fecal smear with a fresh sample of the cat's fecal material. These tests allow Giardia cysts or trophozoites to be identified under a microscope. A negative test result does not mean the animal does not have Giardia, because the Giardia cysts and trophozoites are not always passed in every bowel movement. Repeated fresh fecal samples may need to be examined over a period of a few days to determine the presence of Giardia.
Other tests are available for the detection of Giardia. Now available in some areas, a test called ELISA analyses for Giardia antigens in a fecal sample. Another type of test is a direct immunofluorescent test that detects the presence of Giardia cysts in feces. This test has to be sent off to a special laboratory, so there is a delay in receiving the results.
