Beware of lake and river water

Giardia in lakes and streams.

Giardiosis is a disease that humans can contract by drinking water from a contaminated source, such as a pond, lake or even a puddle. The disease is caused by a microscopic parasite called Giardia, which can infect the intestines of both humans and animals.

Giardia are generally found in North American water bodies. The parasite is thought to come from the feces of infected birds, rodents, cattle, pets and humans. Beaver-dammed waterways are also thought to be conducive to transmission. Animals, especially dogs, that lick their paws after walking in contaminated water can also become infected.

The Giardia parasite is extremely resistant and can survive outside a host for long periods, even in cold, damp environments.
Giardia is a worrying parasite in several respects. It represents a threat to human health, as it can be transmitted to humans and cause severe gastrointestinal disease.

In some cases, infected individuals can carry the parasite without showing symptoms. In animals, it can cause severe vomiting and diarrhea. In symptom-free animals, the parasite can still inflict severe damage by depriving the intestines of essential nutrients during digestion, causing weight loss or lethargy. In some species, Giardia is associated with allergies.

Since it's virtually impossible to prevent dogs from drinking water outdoors, it's important that your veterinarian regularly tests your dog's stools, especially at the end of summer. There's a new vaccine that prevents the disease, and is easy and safe to inoculate. Consult your veterinarian to find out more about this vaccine and other aspects of the disease.