Many Breeders and Vets have their own way of doing their vaccination programs. I am a Breeder and I vaccinate my puppies at 6 weeks with a live C3, then at 12 weeks they get their C5, they are at their new homes by then, and a booster is given at 16 weeks of C5. As for isolation periods after their first vaccination I ask for the puppies not to go to places where alot of dogs go, and ask their owners to keep them inside their backyards. At 12 weeks most obedience schools start their puppy classes after they have had their 2nd vaccination. Like I said each Breeder and Vet has their own program. I think it also depends on where you live, e.g down the coast they have ticks, I live in a tick free area, so I don't need to use Advantix or similar products. I do not use flea treatments as my dogs do not get fleas, When I go to dog shows I give them a natural flea rinse when bath them and I have never had any flea problems. At the off leash park in Bowral, there is a large bucket that gets filled up with water and every dog drinks from it, some people change the water but mostly all the dogs dig in and drink it. I supply my dogs with their own water to be on the safe side. If I were you I would ask your vet as he can answer your question better as he knows what dogs come in to the surgey, whether e.g. Kennel Cough may be running rampant or their might be cases of parvo the have had to deal with. Personally I would rather be safe than sorry, especially seeing you work in a Shelter. Hope I have been of some help.