I’ll tell u why….;
Dogs remember (or pay) kindness with the rest of his/her life… I give it small piece of biscuit or a drop of milk, and his/her heart will be yours forever…no matter how hard you beat it…
Dogs will never bite the hands that feed his/her..unlike human, it is not his/her ability to betray. Even if its hurts you, he/she do it not on purpose, or you make him/her do it.
Dogs is a creature that so easily being happy.. and IMHO, Happy is one kind of Thankfull attitude.