It happened just after 2 a.m. in central Indiana's Grant County.
A trooper was patrolling I-69 near the 263 mile-marker when he saw the cab of a 2012 Volvo truck and trailer, engulfed in flames. The Volvo's driver had gotten out safely.
A trooper and deputy were able to rescue the Shrine Circus animals, including five zebras, four camels and a miniature horse.
Sheriff's officers shared photos showing the camels and zebras strolling along the highway.
The trooper and deputy were treated for smoke inhalation at a local hospital and were later released.
A preliminary investigation revealed that equipment failure caused the fire.