Similar to some others, I'm more concerned about the germs I'll collect from other humans than from my dogs. So many people use a toilet facility that has been used by thousands of others, and so few wash their hands, then open the door to leave the washroom, further spreading the germs, then want to shake my hand when they greet me. ICK. I'll take my dogs' licking...I know where those tongues have been, at least.
Same reason we prefer RVing -- just can't fathom sleeping overnight in a hotel room that has been shared by thousands of others who I don't know.
Then there's the present expert train of thought that the increased allergies being experienced by humans is because they aren't exposed to stuff in their youth. Their bodies don't build natural immunities because humans have become paranoid about bacteria and germs.
Farm kids have less allergies according to the TV show, Nature of Things. Yet they live in an environment full of crap, literally.
http://www.cbc.ca/natureofthings/episodes/the-allergy-fixExcerpts:
Clues to the increase may be found on farms, because kids growing up on dairy farms have far fewer allergies than city kids. It’s called “the farming effect”, after a German study revealed farm kids had only half the allergies of urban kids. It seems that without the kinds of bacteria that have traditionally lived around us and within us for hundreds of thousands of years, our immune systems have become confused.AND
Since discovering the germ theory of disease, we have cleaned up our world. We’ve sanitized our urban environment and mostly defeated bacteria with antibiotics. But at what cost? The antibiotics may be killing off microbes in our gut that work symbiotically with our immune system. A theory known as “the hygiene hypothesis” suggests that exposure to certain germs actually protects our system and lowers our allergy risk.