A Long Island man has been arrested for beating his helpless dog so badly it had to be euthanized after suffering a major head wound.

Michael Gallagher allegedly attacked his Shepherd mix in front of his home around 2.45pm on Friday, the New York Post reported.

The 56-year-old reportedly choked the dog with a plastic zip tie and put it in a trash bag before hitting the animal over the head with a shovel.

Michael Gallagher (left) allegedly attacked his Shepherd mix (right) in front of his home around 2.45pm on Friday, authorities said

His neighbor, who witnessed the savage attack, confronted Gallagher, who then left his yard, the Post reported.

Officers told the newspaper the neighbor opened the bag and cut the zip tie from the dog’s neck.

The neighbor also discovered that the helpless animal had a large head wound.

When authorities responded to the scene, they transported the dog to the Levittown Animal Hospital, where it was euthanized, according to the Post.

Police didn’t locate Gallagher until 10.30pm Friday night near a 7 Eleven.

Gallagher was charged with aggravated cruelty to animals and torturing or injuring animals/failure to provide sustenance.