Things to Know About Giardia 

                               By: Dr. Michelle Nguyen 

Most of us have all heard of Giardia infection in humans causing awful diarrhea.  Well dogs and cats can get Giardia, an intestinal protozoan parasite, as well.  Transmission of the parasite is via the fecal-oral route and occurs when animals ingest fecal material containing the cyst (infective stage) from an infected animal.  Clinical signs may vary from pet to pet, however the most common presenting complaint in animals with Giardia infection is diarrhea.


Diagnosing Giardia infection requires a fecal sample from your pet.  The sample will be sent off to the lab for a clinical pathologist to read and results typically return in 1-2 days.  If Giardia infection is confirmed, your veterinarian will then prescribe an anti-protozoal medication.  After completion of the medication, another fecal sample should be submitted in order to confirm that the infection has been cleared.  


Giardia cysts are immediately infective when passed in the feces and can survive in the environment.  As a result, feces containing these cysts are a source of infection and reinfection for your pet.  Removing feces regularly can limit environmental contamination.  The best way to prevent infection is to avoid situations where your pet can come into contact with contaminated substances, such as exposure to and drinking contaminated water.  Having good hygiene by washing your hands between petting your dog and other dogs, as well as after handling fecal material are great prevention methods. Giardia is a treatable disease with a good prognosis. Regular veterinary check-ups, with fecal examination, are especially important in the diagnosis of Giardia.