When an animal tries to lick a person's face or mouth, it is looking for sugar or salt that humans have in their skin. There is no affection involved - as many people wrongly assume.
When a man kisses an animal he degrades himself to the level of the animal. This kind of equality between man and animal is repulsive to good customs, Natural Law and upright Catholic behavior.
Furthermore, this sentimental interaction with animals has been the origin of countless diseases, included venereal diseases and AIDS.
There is every reason to avoid it.
Don't kiss animals and don’t allow your children to do so.
Elaine M. Jordan