Firefighters used used hydraulic rescue equipment to free the driver of the vehicle after the accident in Southwick Road shortly after 6 pm.
A 999 call reported the incident, and saw Scottish Fire and Rescue Service (SFRS) crews mobilised from the town and nearby Castle Douglas.
The caller believed two people were trapped in the vehicle and reported it was leaking fuel with smoke visible.
First responders reached the scene six minutes later and crew manager Norman Neilson, the incident commander, said: “When we arrived we found there was one person inside the car as well as a dog.
“Firefighters stabilised the vehicle and took the passenger-side door off to give paramedics access to the casualty.”
Mr Neilson added: “We assisted them in extricating the driver who was then taken to hospital by ambulance.
“The dog appeared well.”