This post is over 2 years old not certain why it has been dragged up again ...
He is Just experimenting with what is available he is a boy entering puberty. The only thing that may be weong with him is the haunting memory of you catching and confronting him. I'm sure he is very embarassed. I believe there are many things mothers (women in general) should not know about the male mind
No nothing wrong he is just being affectionate and kissing the dog back, animals are full of love, but obviously its not a good idea as far as Hygeine is concerned so expain this to him, dont go overboard simply explain dogs lick them selves and patting the doggy is better for both of them, no mental issue here.. I may have kissed a couple of dogs in my time...