The M4 was shut in both directions between junctions 12 and 13 after a horsebox burst a tyre yesterday (17 September).
Thames Valley Police and the fire service were called out at 1.07pm as the horsebox had gas canisters on board.
These were thought to contain highly explosive propane gas and could not be dealt with until the horse was removed from the vehicle.
The motorway was shut between Theale and Chieveley at 2pm causing extensive congestion.
Police escorted the second recovery horsebox to junction 12 and the carriageway was re-opened just before 3pm.
No-one was injured in the accident and the horse was safely transported back home.