A woman whose mother fled to the United States to escape the pogroms has expressed her shock at finding a horse named Pogrom competing in an Arizona championship.
Pogrom, a Polish colt, had been lent to Scottsdale's Midwest Training Centre by the Polish government.
Nettie Sacks, 79, whose mother and grandparents left Europe in 1915 after a pogrom, told the Arizona Central news site that she was astonished by the name.
"To me, the word means when the Polish peasants formed a group and they called it a pogrom and they went to all the little villages to find the Jews and kill them all," she said.
But Sue Adams, from the training centre, defended the choice on the basis that the word meant "an invincible leader" in Polish.
"They did not intend to choose a name that would be offensive," she said.
"We can all agree that it was a most unfortunate choice of names for a horse that has matured into a magnificent champion stallion with a promising future here."