You fail to grasp the fact that a sexually mature non-human animal is not a sexually juvenile human, that an incapacitated human is not a free non-human and that sexual contact can and does happen without "slavery."

If it involves animals, it sure is.

Why?

they can't consent

Why?

Yea, what's your point? Humans are much more advanced than dogs. Are you really implying that my logic in nonconsentual sex being wrong is flawed because primitive animals have sex?

If you're assigning the same standard to consent as you would between two humans, then yes. The standard of consent used between humans works really well because it's tailored to humans. Verbal consent works because that verbal part is humanity's most authoritative form of communication, second perhaps, to the written word.

Consent exists in the form that it does as a means for prevention of three fundamental consequences -- most importantly preventing trauma, but also inhibiting the spread of STIs and preventing unwanted pregnancies. The latter two, due to the extreme rarity of zoonoses and insurmountable prezygotic barriers, don't apply when humans and nonhuman animals have sexual relations.

Now, trauma in nonhuman animals is observable, and sex doesn't have the same significance to most nonhuman animals as it does for humans. Nobody here would condone causing trauma, or choose to cause it themselves; that's why we religiously advocate that people seeking a nonhuman animal as a sexual partner know all the intricacies of how they communicate. Avoidance behavior and signs of discomfort are the equivalent of a red stop light here.

Anyway, on the issue of consent, there is a form of consent that can be used -- their body language. Most nonhuman animals (and all mammals as I understand it) have distinct body language that indicates sexual willingness. And of course, when concerning male nonhuman animals, deciding to mount is essentially consent on their part.

Oh and, it's a common spelling mistake, but "consentual" is actually spelled "consensual". It seems weird and arbitrary when writing(and to an extent it is, to be honest), but it makes for much more intuitive pronunciation, despite the less logical spelling. Consentual pops up here and there, but is considered nonstandard spelling and propagated itself through typos in legal settings by and large. No worries though, I just find English to be rather fascinating and wanted to share. :)

Is sex with a preteen as a legal adult wrong?

I suspect that you're equating adult nonhuman animals to children here, at least in the sense of their mental state. While it's a handy shortcut to say, for instance, that a dog has the mental capacity of a child, it bears stating that it doesn't mean they have minds like children; they don't, they're, on a fundamental level, unique to that of humans.

An adult human having sexual relations with a preteen causes empirically observable damage -- the issue is that they aren't ready for sex. The canine, equine, etc partners that our users have are sexually, mentally, and physically mature, however. They're ready for sex and would have it anyway at that point. Many are taken for regular vet visits, and they're at the pinnacle of health.

Is sex with an incapacitated male or female wrong?

Of course. Restraints and mind altering drugs being used during intercourse with a nonhuman animal is not acceptable here and shouldn't be accepted anywhere. But a mentally sound, adult, and well cared for nonhuman animal that can reasonably show willingness or aversion is fine.

Is sexual slavery wrong?

Yeah. Sexual agency is extremely important. If the nonhuman animal doesn't want it, the zoophile doesn't do it. There are a number of occasions where a nonhuman animal has actually solicited their human partner for it, even when said zoophile isn't in the mood. It's very much a mutual affair, just like how it is between humans.

The people here don't have nonhuman animal partners because of fantasies or fetishes, mind. It's a genuine attraction -- no power dynamic, no degradation, no taboo, or any of that. Those things are often actively avoided in favor of what can be considered a 'pure' relationship. It's rare that you'll see a zoophile who thinks of nonhuman animals or their partners as anything less than an equal, hence why a non-zoophile decided to moderate this subreddit.

It also bears mentioning that the relationship a zoophile has with a nonhuman animal partner is much more than just sexual. There is often an element of romance for the zoophile, as well as the usual and close bond between caretaker and nonhuman animal

Burden of proof is on you.

He wanted to get banned.