A police officer shot and injured a dog that ran towards him in the Bronx early Friday, cops said.

The cop was investigating a trespassing complaint at around 12:30 a.m. when the pitbull broke free from its owner and charged him outside of a building on Rev James A Polite Avenue, near East 165th Street, authorities said.

The dog had been leashed, but somehow got away from the 21-year-old woman walking it.

The officer squeezed off three shots, striking the dog at least once, cops said.

The wounded pooch was taken to a nearby animal medical center.

Nobody else was injured from the gunshots.