I've used the Proguard DPV...for those puppies leaving my house it is given first around 8 weeks (a few days earlier or later dependent on when puppy is going home as I prefer that both don't happen at the same time), and again at 12 and also at 16 (either with me or their own vet) if needed. For my own pups I usually wait until 9-10 weeks or so, and then vaccinate again at 15-16 weeks and call it good (I'm still not quite comfortable pushing it back that far with someone else's pup). It's a small sample size (23)...but I've never had sick pup.
Oh, and my puppies start going along with me to herding at 5 weeks where they herd ducks and hang out in an x-pen (we see 50+ dogs a week), so they're definitely not leading a sheltered life prior to completing their vaccines
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