09-12-2018, 11:57 AM
Dogs do it as a sign of intimacy and caring. They don't tend to do it with someone they don't like.
And dogs aren't alone. I've similarly received kisses from horses whom enjoy my company, and parrots.
No, they don't put the same hangups we humans do. Dogs and horses, especially, aren't monogamous ... but monogamy is not the only form of love.