Condom reactions in dogs I've heard of. Which isn't really all that surprising - Latex (which is what all non-synthetic rubber, including most condoms, starts out as) allergies/sensitivities are one of the most common there are after mosquito saliva (almost every human on the planet is allergic to that to some degree), urushiol (the stuff that makes poison ivy/oak/sumac so evil) (again, almost everybody is allergic to it, and the fortunate few who claim they aren't are just waiting for the right (or wrong, if you prefer) exposure before they experience the joy of it) and peanuts.
That said, I've never heard of any sort of canine or equine reaction to human semen more serious than "Lemme lick that up" or "Look what you left dribbling down my leg, you naughty boy!"
Doesn't mean that it can't happen - allergies are so damned unpredictable (at least among humans) that you can go from "I'm allergic to absolutely nothing" to "I'm so allergic to _________ that just being in the same room with some of it might make me drop dead" with no warning of any kind at all, and literally overnight.