NYC woman battles in court for custody of Golden Retriever named ‘Joey’

This court battle is a real dogfight.

An Upper West Side woman claims her ex has been threatening to take back the Golden Retriever he gifted her while they dated — so she wants a judge to declare her the canine’s rightful owner.

Brittney Koop, 30, said she never asked for a dog but that then-boyfriend Jonathan Mass, 44, showed up one day with a bundle of joy they named Joey. She soon fell in love with the furball.

Koop “was gracious for this wonderful gift and after looking into the bright eyes of the adorable pup, she brought the dog home with her and began living life as Joey’s ‘mother’ by providing shelter, food, toys, and love,” she said in a Manhattan Supreme Court lawsuit.

The pair began dating in September 2020, when Koop “was in a very desperate state of mind because the world was in such a chaotic and uncertain state,” according to the litigation.

Shortly after Mass bought Joey from a breeder in Texas and gave her to Koop, the relationship hit the rocks, Koop said in legal papers she filed last week against Mass.

Koop continued to let the Bronx man visit Joey, until he started sending “hateful” text messages and demanding she hand over the pup, she claimed in the litigation.

“You are literally the most selfish piece of sh-t I have ever met,” Mass allegedly wrote, adding, “YOU DON’T DESEVE HER [sic] — you’re just a selfish f–k.”

“I want Joey and I’m done,” Mass wrote in another text, calling Koop “straight garbage.”

Koop forked over $2,500 to him on March 29 for “co-ownership” of Joey, an amount she later realized was “likely more than the full amount paid for the dog,” she said in the legal papers.

Despite the payment, Mass showed up anyway last month, demanding to take Joey — an outburst which prompted Koop to rush the pup to an “undisclosed location” to prevent a dognapping, she said in court papers.

Mass, who said he paid $4,000 for Joey, insisted, “the dog was not a gift” and that the animal “never lived with” Koop.

“It’s my dog,” he told The Post. “I’m going to wait for our [court] date … I’m going to present my proof. She paid me for co-ownership, that was a trial thing.”

He dismissed the angry texts cited by Koop, saying, “Everybody texts angry things.”