Horsing Around wrote:

Burger King To DNA Test Its Beef After Food Processor Used Horse Meat

The basis for horse meat being a taboo food in most/many countries is a
long and complicated story.

Not only does the wiki article say that a Kentucky Derby winner was
believed slaughtered for Japanese pet food, but has this par in that regard:

// There is a misconception that horses are commonly slaughtered for pet
food, however. In many countries, like the United States, horse meat was
outlawed in pet food in the 1970s. American horse meat is considered a
delicacy in Europe and Japan, and its cost is in line with veal,[36] so
it would be prohibitively expensive in many countries for pet food. //
http://en.wikipedia.org/wiki/Horsemeat


--
Mike Easter