Sometimes when I see the results of a scientific study, I can’t help but think, "That’s interesting, but how relevant is it to my life?" That was not the case when I ran across "Prevalence of Giardia and Cryptosporidium species in dog park attending dogs compared to non-dog park attending dogs in one region of Colorado."
The researchers are from Colorado State University (CSU), and there are two big dog parks within a couple of miles of campus, both of which my dog regularly attends; so I read this paper with an extra degree of interest.
The scientists collected feces from and surveyed the owners of 129 dogs that belonged to students or staff from CSU. Analysis of the fecal samples (66 from dog park attendees and 63 from non-dog park attendees) revealed that the dogs that frequented dog parks were more likely to be infected with Giardia and Cryptosporidium than dogs that did not. Overall, the prevalence of all gastrointestinal parasites in the 129 dogs was 7 percent. These results are not too surprising. After all, dogs poop at the dog park, and GI parasites are primarily transmitted through contact with contaminated feces.
Interestingly, no correlation was found between dog park attendance and clinical signs associated with gastrointestinal parasitism (e.g., diarrhea, vomiting, or inappetence). This can probably be explained by the fact that a healthy adult dog’s immune system is often able to control Giardia and Cryptosporidium infections to the point where no symptoms develop. Also, the study’s sample size was not very large. It is possible that a larger study that is more representative of the general population (i.e., not just veterinary students and staff) could have different results in this regard.
The take-home message from this research is this
If you take your dog to the dog park, you need to put extra emphasis on your gastrointestinal parasite control program.
Many heartworm preventatives and broad spectrum dewormers do a good job of controlling hookworm, roundworm, and sometimes whipworm infestations, but they are ineffective against other types of parasites, including Giardia and Cryptosporidium. Fecal examinations are not foolproof either, which is why I typically recommend a combination of fecal testing and prophylactic deworming for dogs at significant risk of parasitism.
Even more importantly, if your dog develops symptoms consistent with gastrointestinal parasitism, make sure that your veterinarian knows whether or not your dog attends a dog park or comes in frequent contact with canine fecal material in any another way. Diagnosing a Giardia or Cryptosporidium infection is not always easy, and your veterinarian will need to get an idea of your dog’s individual risk factors to decide which diagnostic tests are most likely to bear fruit.