The Redlands Animal Shelter in California is looking into bird control measures after blaming Giardia infections in dogs on exposure to wild bird poop. On Facebook, Redlands Friends of Shelter Animals have declared "We have a serious problem with birds at the shelter. They land on the kennels and poop goes into the water bowls and give the dogs giardia – which is a parasite that gives them explosive diarrhea."
Giardia is a protozoal parasite that can cause diarrhea in dogs and other species. It can also be carried by healthy dogs, at relatively high rates in some groups. The scope of the problem at the Redlands shelter isn’t clear since the news article only talks about one case. Whatever the scope, shelter management is blaming the birds.
Apparently, discussions are underway with different companies about a solution to the bird problem, something that is anticipated to be expensive. However, it’s all too common for people to jump the gun on expensive interventions when there’s an outbreak and overlook the root causes. While news reports don’t always give the whole story, I’d be wary about blaming birds without much more evidence.
Can wild birds carry Giardia? Yes. However, there’s more to the Giardia story than that. It doesn’t sound like they’ve actually tested the bird feces to determine whether Giardia is there. Additionally (and critically) it doesn’t sound like they’ve determined the type of Giardia that’s infecting the dogs. There are different types (assemblages) of Giardia and most have a limited range of species they can infect. The vast majority of dogs with Giardia in most regions are infected by Assemblage D, a dog-specific strain that comes from other dogs and poses no risk to people. I’m not aware of Assemblage D being found in birds. Dogs can also be infected by Assemblage A, a type that infects people, and also can infect birds.
So, if Assemblage D is involved, they need to look at transmission between dogs within the shelter. If Assemblage A is involved, they still need to focus on dogs but could investigate birds as a potential source.
Overall, Giardia transmission is much more likely due to breakdowns in cleaning, disinfection, hand hygiene and general shelter practices rather than birds pooping in water bowls. It’s a lot cheaper to address these shelter management practices (which will also help control various other infectious diseases) rather than dumping a lot of money into controlling bird exposure when in fact that may not be causing the problem. Trying to reduce exposure to bird poop is a good thing as a general practice, but it’s important to focus efforts and resources on finding and addressing the true root problems during an outbreak.
More information about Giardia can be found on the Worms & Germs Resources page.