Due to "popular demand" from my last post, I did a little research into the French habit of horsemeat consumption, and here are a few interesting tidbits for you:
The official term for the phenomenon is hippophagy. From Wikipedia (which, as we all know, is not the definitive authority on anything, but informative nonetheless):
According to legend, the French taste for horse meat dates from the Battle of Eylau in 1807, when the surgeon-in-chief of Napoleon's Grand Army, Baron Dominique-Jean Larrey, advised the starving troops to eat the flesh of dead battlefield horses. The cavalry used breastplates as cooking pans and gunpowder as seasoning, and thus founded a tradition.
Today many European countries including France, Italy, Romania, the Netherlands, Spain, Portugal, Switzerland and Belgium consume horse meat in notable volumes. In France, specialized butcher shops (boucheries chevalines) sell horsemeat, as ordinary butcher shops do not have the right to deal in it.
I don't know about the claims made in that article, but I know that the last part about special butcher shops is wrong. Those shops do exist, but other places do have the right to sell horsemeat--it was for sale at my local Atac supermarket in Tours. You can't miss that huge mass of bright (and I do mean BRIGHT) red meat lying there.
Another interesting discovery was a film on this subject (from the NY Times):
Result of Eating Horse Meat--1908
PLOT DESCRIPTION: The plot and comedy content of this Pathé film are both summed up by its title. The incredibly stupid hero buys horse meat at the local butcher then takes it home and wolfs it down. As expected, the dimwitted diner begins behaving like a horse himself. He gallops around the city, knocking over people and props with furious abandon. Arrested by the gendarmes and thrown in jail, the hero finally overcomes his delusions. Too bad: With a little luck, he could have become another Nijinsky, or might even have won the Kentucky Derby.
From what I read, there is no breed that is off-limits to this sort of thing. Presumably, you would not want to butcher an animal that had some sort of value, such as a race or work horse. There are farmers who breed horses specifically for butchering, but I couldn't find a listing of specific breeds.
So there you go--maybe I answered your questions, maybe I didn't--but it was interesting to try to find out more about the subject.