Diarrhea has a number of causes, but one that we’ve seen quite a bit in our patients recently is Giardia, a parasite that is transmitted in stool (Giardia can be transmitted to humans in this way, but people most often get this parasite from contaminated water). Once a pet is infected, it will typically take 5-12 days in dogs and 5-16 days in cats for the parasite to be found in the stool — however, diarrhea can occur before the parasite actually shows up in the stool.
To diagnose Giardia, your veterinarian will need a fresh stool sample from your pet. As this parasite cannot be detected by the naked eye, the doctor will examine the sample under a microscope. Sometimes the test may need to be repeated, as this parasite can shed intermittently — so while an initial test may come up negative, further tests may come up positive. A newer variety of test is the “snap test,” which tests for Giardia proteins in the stool. The snap test does help improve diagnosis; however, while almost all veterinarians have the capability to look at a stool sample under the microscope, the snap test is less readily available, and not all veterinarians will be able to offer it.
© 2011 Greenbrier Emergency Animal Hospital. All rights reserved.