I think some people are naturally attracted to animals, just the way their brains are wired.
I think that sexual repression, as well as abuse and other factors, can lead to paraphilias, but I do not think that there are people who are born attracted to donkeys the way a person is born attracted to opposite gender or same gender.
Also, when the Catholic pederasty scandal came out I thought to myself being disallowed a marriage, sex, and masturbation MIGHT have led these men to these actions. Or they could have been latent paedophiles? But I'm not sure about this either.
I think that barring men who are married from serving as priests meant that a lot of men who really aren't interested in marrying another adult entered vocation and some of them turned out to be paedophiles. Just as I am sure some of them are gay men who struggle with their own faith's teaching on gayness and see vocation as a "way out" of "sinning, and then I'm sure some are totally asexual and some are straight but think that their love for god will get them through it. For the most part, when priests and nuns engage in "sexual misconduct" it is with another adult, not a child. In other words, those people know that the way to relieve the repression they volunteered for is with another adult, not to go after a child.
I don't know why the abuse was much more rampant in Ireland than in the US, by which I mean all different areas of the church were involved (orphanages, women's homes, etc), males and females, whereas in the US, it was mostly priests and some nuns, but so far have not heard of abuse at, say, Catholic run hospitals or foster homes and the like. Did the political power that the Republic of Ireland handed the Church after independence create depravity and deviance in priests, brothers and nuns where it might not have existed had those people been married or the Church less all-powerful? I think in some years we will hear of similar scandals in South America as well.