The protocol for
dogs and cats living in cities may be very different than what is appropriate for free
roaming dogs or cats living in communities where the majority of
dogs and cats are not vaccinated
regularly or at all.
The U.S. had abundant free -
roaming dogs from settlement times until the advent of motorized transportation in the early 20th century, which gradually drove working animals out of the streets, closely followed by the introduction of
regularly scheduled urban garbage disposal, enclosed sewers, near - universal access to indoor plumbing in urban areas, and home refrigeration.