Police say the officer's vehicle was rear-ended by a tractor-trailer unit hauling livestock on Deerfoot Trail, a freeway that runs north-south through the city.
The officer's injuries were not serious, although the collision caused extensive damage to the vehicles.
Police say a second person, an occupant from the vehicle originally stopped by the officer, also had minor injuries.
Traffic had to be diverted for a time while investigators were on the scene.
Police say there are no indications at this time if alcohol or speed were factors.