The article also mentioned that the Humane Society is suggesting mass birth control instead of horseacide....horsecaust?
Let's go with equicide. -cide comes from the latin word caedere, or "kill" as in homicide, infanticide, etc. Horse is english from old high german, so it doesn't work with -cide. (Mixing languages is bad form.) Horsecaust?! Caustic is from a greek word for burn, as in "holocaust" which means a great fire holo=light + caust=burn, as in "caustic humor." Horsecaust just amounts to a peurile, cacophonic portmanteau, both etymologically and phonically offensive. Equus is latin for "horse" and pairs well, both linguistically and euphonically, with -cide.
What's interesting about Horses is that the modern genus evolved in North America, according to the fossil record, then raced across the land bridging the Bering Straits during one of the Pleistocene Ice Ages, populated Eurasia, then died out here, probably due to overhunting by early man tens of thousands of years ago. They were then re-introduced by the Spaniards some 500 years ago. Coming home, as it were. Man kills off horses in North America, then man brings it back. Now, man wants to kill it off again.
Ah, I've never ridden a horse and, to be honest, they make me a little nervous. They're smelly and large. I say let them run free in the wild. If they overpopulate the problem will take care of itself. Overpopulation is wonderful that way. If any species breeds faster than its food source will allow, mass starvation occurs. Overpopulation problem solved. Everybody wins.