The Bureau of Land Management has issued a decision that could mean tens of thousands of so called wild horses and burros could be killed to control their burgeoning numbers. The decision has sparked an outcry from animal rights groups that is mortified by the BLM’s plan.

The plan could affect as many as 45,000 feral horses and burros that are in government corrals mostly in the Western United States.

The 1971 Wild Free-Roaming Horses and Burros act gives the BLM authority over protection and control of all the animals. The law allows and authorizes the agency to kill as many animals as necessary to protect federal rangelands from over grazing and damage.

In all there are another 67,000 feral horses and mules running wild on federal lands in 10 western states.