Giardia

You and your trusted canine companion are enjoying a great mountain hike when you stop to drink some seemingly fresh water from a running stream. Looks tempting, right? Well, looks can be deceiving, since there's a good chance this stream is filled with more than just clear-looking water. The truth is, this stream may be teeming with giardia or other potentially serious parasites. Actually, you need to be careful when drinking unpurified water, and so do your pets. Giardia is the most common internal parasite affecting humans and pets in the United States. It is a microscopic single celled organism, and people can become infected by exposure to contaminated water. Our pets typically acquire the disease from lapping at dirty puddles in their neighborhood or backyard.

Giardiasis causes diarrhea that may wax and wane. It may clear up on its own only to recur at a later date without additional exposure. The soft stool may have a mucous coating, and may even have some blood, but fortunately, the majority of the time, it is not severe enough to be debilitating. Occasionally, pets can become depressed, lose their appetites, and weight loss can result. It often takes a week or more for a person or pet to develop diarrhea after ingesting the organism

Determining if your pet has giardia can be very frustrating with standard testing methods because of the very complex life cycle of this protozoon. Giardia has two life stages, the trophozoite and cyst. The trophozoite, or `troph', resides in the intestinal tract. Scientists don't fully understand how these `trophs' cause the diarrhea, but suffice it to say, they do. Either right before they are shed by the body in the stool or shortly thereafter, the trophs form cysts, which are very resistant to the harsh elements of the environment. If the cysts are deposited in a moist protected area such as the damp areas of a backyard, they can survive in the location for months.

Routine fecal testing involves suspending a sample of the stool in a special solution. Since the giardia organism is shed at a variable rate, it may take testing several different stool samples to find the giardia cyst. However, thanks to the same technological advances that have brought us the human home pregnancy test, fecal samples can now be subjected to an immunological analysis called an elisa test. It is much more accurate at determining if an intestinal upset is due to giardia.

And it is not just the diagnosis of giardia that can be trying, as the treatment can be equally as taxing. There are several medications that your veterinarian can dispense, and since no one medication is 100% effective, it may take several attempts, often with a combination of medications, to eradicate the organism. Though a vaccine is available, it does not prevent a pet from acquiring giardia but will reduce the shedding of the cysts.

Environmental decontamination is essential. Wash bedding, use dilute bleach on hard surfaces and give your pet a good bath because the organism can stick to its fur.