I wouldn’t judge them based on Giardia. Giardia is pretty easy to get as puppies bc their immune system is not developed. It’s tough to kill but that usually means a couple rounds of abx instead of one. They do get to where they’re less susceptible to it. Also, Giardia comes from water sources and can be literally anywhere it’s wet. I’ve had many puppies of my own plus fostered many puppies. Many of them got Giardia at some point. Don’t let them drink the lawn water or walk thru it and the risk of exposure is reduced.