Beagle PupThe parasite Giardia often raises concern for both dog and human health. In reality, while it’s a potential problem, it’s probably over-rated (or at least there’s a bit too much paranoia at times). A reasonabe percentage of healthy dogs (probably ~7% in Ontario) are shedding the parasite at any given time, but very few will go on to develop disease. It can cause diarrhea, but only in a small minority of exposed animals, and usually it’s not a big deal. Giardia also a zoonotic pathogen, but as we’ve learned more about this parasite in recent years, it’s becoming clear that pets pose a limited risk to people. Most studies have identified Giardia found in dogs to be dog-specific strains that do not infect people.

Here are some interesting tidbits about Giardia from a few recent papers.

Does that mean we should just ignore Giardia? No. It can definitely cause disease in dogs, and sometimes it’s hard to treat. It can also cause disease in people (I spent a couple days in hospital with Giardia many years ago… never did figure out how I got it). It’s important to remain balanced, though. Pets are a minimal to inconsequential source and people shouldn’t freak out if their dog is diagnosed with Giardia. At the same time, it’s a “don’t eat poop” disease, so basic prevention practices are easy.