Fire crews were called to the Robles Frame Body and Fender Shop on Anna Street and Braly Avenue around midnight.
When firefighters arrived, flames were tearing through the building.
Crews were able to stop the spread from connecting to officers. However, several cars inside the shop burned.
Hazmat crews were also called to the scene to secure the area due to the types of materials burning.
"These automotive fires are dangerous because of the toxins that are there, the tires, the fuels, all the stuff that goes into automotive repair," said Fresno Fire Battalion Chief Daniel O'Meara. "It's very dangerous once it starts burning, and when it starts mixing together it does create a lot more hazards for us."
Firefighters were able to save Rottweiler that was inside the building.
It took around 50 firefighters to battle the blaze. No one was hurt.
The cause of the fire is under investigation.