A police officer and his re-trained dog wait at a security checkpoint in Saltillo
A police officer and his re-trained dog wait at a security checkpoint in Saltillo, Mexico March 4, 2016. Stray dogs are adopted by the police from a municipal anti-rabies centre and then trained to help the police patrol the streets, and search for drugs, explosives and weapons. Picture taken March 4, 2016. REUTERS/Daniel Becerril