I have heard that in some states there are trainers who will not only do snake-breaking, but skunk- and porky- breaking as well. I have yet to find a trainer in Washington, Idaho, or Oregon who does snake-breaking, much less the others.... Everytime I read a story about a pup getting hit by porky or a skunk, I am tempted to buy a skunk and a porky pelt and do a bit of aversion training myself. We don't generally use the eCollar, just for reinforcing a command they know dang well they are supposed to do, and so far just for a recall. But I think "turning it up to 11" might be appropriate for the aversion.
Everytime we go out we remind the dogs "Do NOT play with any kitties you find. No black & white kitties, no spikey kitties, and for heavens sake no BIG tan kitties!" and of course that does no good other than to remind ourselves to be alert.