A Massachusetts man has pleaded guilty to charges related to a series of abusive acts toward animals at an illegally operated kennel.

As Fox News reported, Jason Gentry, 37, agreed to a plea deal that will require him to testify against the breeder authorities believe he worked with when the mistreatment took place.

Gentry was reportedly employed as a dog trainer at the unlicensed facility located in Lynn.

According to the details presented in pursuit of animal cruelty charges against Gentry, New York-based dog breeder Dominic Donovan allegedly hanged two puppies.

Police say a third died after he forced it to ingest prescription anxiety medication.

Another puppy reportedly died — and several others were injured — when Donovan allegedly cropped their ears without first administering anesthetics.

As WBZ reported, Gentry and Donovan were breeding and training the dogs specifically for aggression, then hanging the dogs that proved too weak or timid.

An investigation into the kennel began in 2014, and Revere Police Chief Joseph Cafarelli expressed deep concern over the nature of the charges when the case became public.

“Anybody who would hurt a puppy because it wasn’t aggressive enough, there’s something wrong,” he said. “There’s a disconnect there somewhere.”

The breeder pleaded not guilty to charges in the case, according to reports. He is currently awaiting trial.

Gentry faced charges related to all four animal deaths, along with the abuse of others dogs. He is expected to be sentenced next month.

[Featured image: Jason Gentry/Suffolk County DA]