The argument was made that non-human mammals engage in homosexual behavior, and that therefore, homosexual behavior is natural, and therefore, good for those humans who are inclined towards it and can consent to it as adults.

The counter-argument was made that non-human mammals engage in cannibalism, and therefore, those behaviors which are natural (like homosexuality) are not necessarily good.

My "dogs breathe" example was an oblique way (sorry) of asking people to examine why they accept homosexual behavior in animals as natural but reject it as "unnatural" when it occurs humans. That is, if breathing is considered natural because "dogs do it, all animals do it, and so it's natural," then if you can demonstrate that animals also engage in homosexual behavior, then you can't say it's unnatural to humans, anymore than you can say breathing is unnatural. As a matter of fact, gay and lesbian sexuality has been observed in apes, birds, fish, dolphins, porpoises, giraffes, and many other animals.

I mean, do you want a bunch of sexually frustrated gays and lesbians running around? Believe me, you do NOT want that to happen.