What's the back-story here? Starting in 2006, Congress started placing provisions in the funding for the U.S. Department of Agriculture that prohibited government funding for inspecting horses destined for food. By 2007, this led to the shutdown of horse slaughterhouses in the United States. In June 2011, the GAO did a report on the aftereffects of the policy, and named the report: "Horse Welfare: Action Needed to Address Unintended Consequences from Cessation of Domestic Slaughter."
Slaughtered in Mexico and Canada instead of the U.S.
The most obvious consequence is that instead of being slaughtered in the U.S., horses were shipped to Canada and especially to Mexico to be slaughtered instead. In 2006, about 100,000 horses were slaughtered in the U.S. By 2010, the number of horsed exported for slaughter had risen by about 100,000. Here's a graph of horses exported from the GAO report:
In other words, the policy didn't save horses. A New York Times story reported in October: "The closing of the country’s last meat processing plant that slaughtered horses for human consumption was hailed as a victory for equine welfare. But five years later just as many American horses are destined for dinner plates to satisfy the still robust appetites for their meat in Europe and Asia. Now they are carved into tartare de cheval or basashi sashimi in Mexico and Canada."
Indeed, the policy probably worsened the treatment of horses at the end of their lives. The horses needed to travel farther before being slaughtered. Their transit was no longer monitored by the USDA. And slaughterhouses in Mexico are not under USDA rules for humane slaughter.
Indeed, in a few cases U.S. firms were re-importing horsemeat from Mexican and Canadian slaughterhouses for use in zoos. GAO writes that as of the end of 2010, "USDA identified at least three establishments—in Colorado, Nebraska, and New Jersey—that import horsemeat for repackaging and distribution to purchasers in the United States who feed the meat to animals at zoos and circuses."
Horse Abuse Expanded
As it has become logistically harder and less remunerative to send a horse to slaughter, the amount horse abuse has been rising. The GAO reported: "Comprehensive, national data are lacking, but state, local government, and animal welfare organizations report a rise in investigations for horse neglect and more abandoned horses since 2007. For example, Colorado data showed that investigations for horse neglect and abuse increased more than 60 percent from 975 in 2005 to 1,588 in 2009. Also, California, Texas, and Florida reported more horses abandoned on private or state land since 2007. ... [T]he Montana Association of Counties reported that the number of horses being abandoned by their owners has rapidly increased since horse slaughter for human consumption was halted in the United States, but the association did not have specific data. In addition, the National Association of Counties reported that the increasing abandonment problem is notexclusive to Montana or the West but is happening nationwide."
Although it was not possible to slaughter horses for human consumption in the U.S., it continued to be legal to bring the corpse of a horse to a rendering plant to be turned into pet food or glue. As GAO explained: "Before 2007, horses were slaughtered in domestic slaughtering facilities only when the horsemeat was destined for consumption by humans or zoo animals. Currently, pet food and other products, including glue, may still be obtained from the corpses of horses that are hauled to rendering plants for disposal. The production of these products is not covered by the requirements of the Federal Meat Inspection Act ..." There doesn't seem to be evidence on this point, but one suspects that some horses that would have ended up in the slaughterhouse before were now ending up at rendering plants.
There are also concerns that wild horses might be being shipped to Mexican and Canadian slaughterhouses. USDA used to work with the Bureau of Land Management to prevent wild horses from being slaughtered in the U.S., but with USDA inspectors out of the picture, it's not clear
Return of the Horse Slaughterhouse
In the aftermath of the new law, the Christian Science Monitor reported: "[M]eat processors are now considering opening facilities in at least a half-dozen states, including Georgia, North Dakota, Nebraska, Oregon, Wyoming, Montana, and possibly Idaho." A number of animal rights groups like the Society for Prevention of Cruelty to Animals are outraged. The president of the U.S. Humane Society, Wayne Pacelle, takes the view that all U.S. horse owners should be required to provide lifetime care for their animals. (Exercise for the reader: Consider some likely unintended consequences that would arise from such a rule.) But as Newkirk, the head of PETA, said about the end of the U.S. horse slaughter ban: "It's hard to call [the end of the horse slaughter ban] a victory, because it's all so unsavory. The [funding] bill didn't mean any horses were spared, but it does mean the amount of suffering is now reduced again."