After the license exam has been cleared it is required for every Veterinarian to complete the internship period. The duration of the training period is also varies from one institution to the other. This may take a minimum of 3 years to the maximum of 5 years to be certified as a Veterinarian.ow long does it take to be a veterinarian? The quickest answer to the question of ‘how long does it take to be a veterinarian?’ is 7 years minimum.