Just my $0.02 ... Call me paraniod if you like...
I do not and would not recommend letting doggies on the floor in Petco or anywhere dogs go (ie. park, vet, groomer) until they are at least 4-5 months old and all their shots have been completed because they are still very suseptible to catching things from other dogs. Not everyone takes as good care of their dogs as we do.

There could be a sick one out there and you do not want to risk that for your little one...JMHO~
But I'm sure your cutie could probably win that contest...I would wait for the next one to come around...