Remember that some people (or their kids) have allergies to certain animals, so it’s always important to inform your potential guests like you would inquire about food allergies, etc.
Then, there are people who have a fear of animals no matter how friendly your think your pet is. Oddly, it’s sometimes the friendliest pet that frightens people the most because of its excitedly happy reaction to the visitors.
By the way, it’s not just dog owners, but also those with cats, large parrots, etc. who need to give this some thought.