Is it because they love us? Is it because we taste good? Is it evolutionary to encourage regurgitation of food? Is it to pacify themselves or us?
There seem to be several reasons – affiliative, attention seeking, stress relieving or tasty! An interesting link.
It’s quite common to go to clients who don’t like their dogs licking them, and somehow just can’t stop them. Here is a very hyper dog I wet to whose owners just couldn’t calm him down – or stop him licking them.
Go to the main website: www.dogidog.co.uk