Animal doctor would be one, vet is another (short for veterinarian).
People doctor :3
veterinarian
Pet doctor
pet-nametag
Doctor.
Person who is a doctor.
Petty
veterinarian.
You could use "Once a doctor and a soldier, ...." or "Previously a doctor and a soldier, ...."
Surgeon
Yes.
Physician is another word for doctor. Doctors may also be referred to as Healthcare Professionals, however the term does have wider applications in the Healthcare sector.
i depends. If you are a doctor, the word for it is incision.
Petroleum