Doggone it, Dad!

A Brooklyn family has posted more than 1,300 fliers on the Upper West Side offering a reward for the return of their 5-year-old Cavalier King Charles spaniel — after their patriarch made the bone-headed decision to give the pooch away to strangers he met on Craigslist.

“He’s been going through a great deal of stress, and so he decided one day to take our dog and lighten the load,” Eva Zaghari said of her husband, Raid, whom she described as “never close to this animal.”

“It was without our consent and it was an irrational act.”

After placing an ad offering cute Cooper for free, Raid met two couples and a man on Sept. 5 at De Witt Clinton dog park on 52nd Street off 11th Avenue, Eva said.

After a brief conversation with the prospective owners, he settled on one of the couples, who told him they lived in “one of the high-rises” in Manhattan and owned a home in the Hamptons, Zaghari said.

Zaghari and her three kids were devastated without the doe-eyed dog they had raised from a puppy.

“We were just dumbfounded . . . I’m married 23 years to the individual so, yes, I just wish he would have made a better choice than to decide one morning on a whim to hand the dog off to someone without even obtaining a contact number.”

Her husband, she said, now feels “awful.”

The family has narrowed its search to the Upper West Side thanks to tipsters who claim to have seen their dog.