i always had the impression that "beaver fever" was the result of filthy people using the waterways as a toilet and the beaver as well as other animals were just bystanders in the cycle of passing the cysts..
giardia epidemiogy You are probably right, 'dogs. Article indicates that critter giardia and people giardia look the same but are genetically different, and it is not clear that beaver giardia can infect folk. The other possibility is sub clinical infection. Some folks can probably live for a long time with a giardia colony on board without a lot of symptoms.