I've used visible Red lasers on hogs for a while now (before IR civilian lasers were near reasonable in price & I didn't have the time/resources/desire to build my own). Bloom "can" be an issue, depending on the environment. Dark nights, high humidity, and a hog with a lot of hair gives me a paper plate sized bloom through my NODs @ 100 yds vs. lots of moon illum, low humidity, less hairy pig gives me ~2" dot.
I don't turn the laser on until I'm getting ready to shoot, and I haven't seen any negative reaction from hogs to it yet. Ergo I'll keep using it until I break down & buy an IR laser. YMMV.