更新1:
i see people with dogs let them lick them all in the mouth. and they in turn will kiss someone else without washing their mouth or brushing their teeth. i know this is a sign of affection from the dog but that could be where a lot of diseases come from ad the doctors can't figure out where these diseases come from. just think when you take the dog out he sniffs other dog's behinds, and all around every where else where other dogs have peed or pooped. then they come and lick you in the mouth.