Giardia is a common intestinal parasite of dogs and cats. Infection prevalence can vary to more than 50%, depending on the population, and up to 100% in shelters and kennels. A recent national study determined the prevalence of
Giardia in symptomatic dogs to be 19% and 11% in cats.
1 Giardiasis is commonly under diagnosed and misdiagnosed due to intermittent shedding and difficulty identifying cysts and trophozoites.
When approaching cases with diarrhea, a comprehensive fecal-testing protocol is recommended because it improves accuracy rates and leads to a faster diagnosis. This protocol combines traditional in-clinic microscopy with in-clinic rapid assay testing. The Companion Animal Parasite Council (CAPC) recommends using a combination of:
- Fecal floatation with centrifugation
- Direct smear
- A sensitive, specific Giardia ELISA
(a Giardia-specific ELISA detects cyst wall proteins that are excreted into the feces in large amounts during the encystation phases)
Other diagnostics available:
- Real-time polymerase chain reaction
(available as IDEXX RealPCR Giardia test and in IDEXX RealPCR Diarrhea Panels)
Giardia Parasite Detection Protocol—in accordance with CAPC Guidelines

View/print the Fecal Tests brochure. (PDF)
Giardia life cycle

Detecting Giardia Infection: A Comparison of In-House Methods vs. Reference Laboratory Methods

Reference
1.
Carlin EP, Bowman DD, Scarlett JM, et al. Prevalence of Giardia in symptomatic dogs and cats throughout the United States as determined by the IDEXX SNAP Giardia Test. Vet Ther. 2006;7(3):199–206.