Firefighters battled a three-alarm blaze just outside Mexico into the early morning hours.

The fire started around 8:30 p.m.at the Everlast Dog Food manufacturing plant.

Crews from the Mexico, Vandalia, and Little Dixie fire departments had the fire under control by midnight.

Firefighters continued to battle hot-spots and the stench of burnt dog-food into the wee hours of the morning.

"It appeared the fire started around the drying facility where they were drying dog food that had just been manufactured," firefighter George Hardy said."It smelled pretty bad. A lot of dog food, a lot of smoke... Fire."

Little Dixie Fire Chief Kenneth Hoover said some firefighters were treated for heat exaustion but reported no major injuries.

Investigators are beginning to search for what caused the fire.