When U.S. customs officials were checking on a large dog kennel inside an airplane that landed at the world’s largest airport, they were surprised to find a hunched-over Miniature Horse looking up at them.

The incident could land the airline and the passenger transporting the horse into some trouble because the USDA says transporting the horse in a kennel falls under animal cruelty regulations, said Customs and Border Protection spokesman Mike Balero. He declined to identify the airline and passenger involved.

A USDA spokesman did not immediately return a phone call for comment on Friday (Sept. 28).

The plane was traveling from Germany to Guatemala with a stop Sept. 18 at Hartsfield-Jackson Atlanta International Airport