[Shade]

I agree about asking the other owner regarding vaccinations

As to having a single dog, it depends on the dog. My first two dogs were singles and they did just fine, I would take them to the dog park and they might play for a bit but preferred humans to other dogs. They probably could have gone the rest of their lives without seeing another dog and be fine

Delgado on the other hand is a total social butterfly and LOVES other dogs, he loves his human pack but much prefers other dogs compared to most humans. I don't think he would be very happy as a single dog

Even if your dog is a social butterfly they'll learn that home is for human interaction only. Set up play dates with other owners you trust and see how it goes, if he really likes other dogs try to make it a regular thing. If not, keep him around humans