Why Dogs? This story is a possible explanation of my sexual fascination with them.
Invariably something sexual in ones early life formulates and later "turns" everyone 'onto' some sexual theme that then excites them for life. This is why I personally do not believe that people of either sex are born homosexual. Naturally if the first "thrill" of sex involves a same sex partnership then this will clearly help to formulate that young person's future sexuality.
In my own humble opinion this is the reason why minors must at all costs be legally protected and kept safe from each and every sexual predator, of either sex.
It's so sad but those 'innocents' abused by adults often do become abusers too in later life.
A lot depends on the young person but if we protect them and leave them alone to form sexual preferences naturally with their own peers they will usually find what "does it" for them, invariably this involves what passes for fairly 'normal' sexual relationships.
Occasionally however wires do get crossed. In the case of Bestiality exciting someone it could even be the result of an old teenage glimpse of dogs copulating in the street and just feeling sexy over that sight? Perhaps spying on others being sexy with dogs? Who knows why?
Whatever, I do know that this if what "did it" for me, spying on my Aunt. These are very accurate true accounts from a long time ago ... long before the internet "corrupted" us all
Do please note despite being "naive" sexually I was in my twenties, thus far from a child.