Here is a recent story:
Less than four years after the last equine slaughterhouses in the U.S. closed down, an unlikely coalition of ranchers, horse owners and animal-welfare groups is trying to bring them back.
…Though horse lovers cheered when the last slaughterhouses were shuttered, some now say they may not have thought through the consequences.
The slaughterhouses disposed of the thousands of horses abandoned or relinquished each year by owners who find them too old or temperamental to be useful or who simply can no longer afford to care for them. Now, many of those horses are sold for $10 or $20 at low-end auctions and packed on crowded trailers to be slaughtered in Mexico. Animal-welfare experts say the horses often suffer greatly on the journey.
In 2006, just 11,080 U.S. horses were shipped to Mexico for slaughter. In 2008, after the American industry shut down, that number jumped to 57,017, according to the U.S. Department of Agriculture.
Animal-rights supporters have been lobbying Congress for a ban on exporting horses for slaughter. They've had no success–but even if a ban did pass, some activists say, it would do little to ease suffering, as owners desperate to shed responsibility for their animals might simply abandon them to starve. Hiring a veterinarian to euthanize and dispose of a horse can cost hundreds of dollars. Horse-rescue groups take in some unwanted animals, but they don't have the resources to care for them all.
What does ethics look like when there are many more beings than can be supported alive by available resources? How much of the animal kingdom falls under this designation? How much of human history? Or does this question not apply to humans?
Here is a story about abandoned horses in Ireland.