Horse slaughter is an inhumane industry which creates the problems it claims to solve by fostering irresponsible breeding. The FDA states horses are not raised as food animals and are treated with chemicals toxic to humans. It poses a threat of contamination to the US food chain.
Horse slaughter is subsidized by taxpayers-USDA inspection of plants and product, tax incentives to breeders. The sequester prompted budget cuts which poses additional threat of exporting unsafe meat to allies and unsuspecting victims.
Waste water and blood from horse slaughter are notorious for overwhelming local waste water infrastructures and poses a significant threat to the environment, especially since numerous drugs with which horses are routinely treated are not safe for humans.