Humans and dogs live together, are they part of the same population? why or why not

I would think no, because usually when we're dealing with population, we're dealing with one specific species. For example, we don't count the population of all living things in the world. Instead, we divide species up and then determine the population. In this situation, the population of the cats would be 1 and the population of the dogs would be 2. They are not the same species, therefore we cannot determine the population when combining them.