Giardia symptoms, diagnosis, and treatment

Giardia is often acquired by drinking contaminated lake or standing water.

One of the most common causes of acute and chronic diarrhea in dogs and cats today is the protozoan parasite known as Giardia. This parasite is most commonly acquired by drinking contaminated lake or standing water. While many pets can have few symptoms, others can develop progressive diarrhea and/or weight loss. For many years we had very insensitive testing in trying to detect this parasite in routine stool checks.

However, with the recent development of the Zinc sulfate flotation method and the Giardia ELISA test, diagnosis of this parasite is now quite easy, as it is being increasingly recognized as a major cause of diarrhea in dogs and cats. This improved method of detection is especially important so that early treatment can be instituted, as Giardia is an example of an intestinal parasite that can potentially be transmitted to people.

Treatment may include 5-10 courses of the prescription antibiotic Metronidazole, as well as a 3-5 day course of Panacur C, which will often treat resistant strains of this emerging parasite. It is important that if your pet has chronic or intermittent diarrhea that you ask your vet about testing the stool specifically for this organism. At the same time I will also recommend a good probiotic such as Fast Balance and NaturVet Enzymes & Probiotics during and after treatment for this parasite, in order to reestablish a normal and healthy digestive tract bacterial population.

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  1. My one year old boston terrier was just diagnosed with giardia. Should I treat my cats also? I caught the dog eating their feces when he was younger and thought he may have gotten it from them. the cats are 12 years old and have rarely gotten outside. None of the pets have had diarrhea. Angie

  2. Dr. Michael Dym, VMD veterinarianAugust 22, 2011 at 10:44 pm

    I would treat the cats with a 5 day course of flagyl and then test their stools.

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