John Fetterman labeled Mehmet Oz a "puppy killer" following a bombshell news article by Jezebel.
The outlet reported on Oz-supervised experiments that resulted in the death of 329 dogs.
Fetterman dragged Oz on Twitter, asking for "help to keep the #PuppyKiller out of the US Senate."
Pennsylvania Democratic Senate candidate John Fetterman slammed his GOP rival Mehmet Oz on Tuesday following a bombshell report on hundreds of dogs that died in experiments linked to the latter.
Fetterman took to Twitter to share a report from Jezebel titled "Dr. Oz's Scientific Experiments Killed Over 300 Dogs, Entire Litter of Puppies."
Published on Monday, the article was a deep dive into scientific studies from Oz published between 1989 and 2010, when he was a principal investigator on 75 projects at the Columbia University Institute of Comparative Medicine.
According to Jezebel's review of the 75 studies, Oz's team conducted experiments on 1,027 live animal subjects, including dogs, pigs, cows, rabbits, and rodents. The outlet reported that 329 dogs died during 34 of these studies and noted that Oz did not kill the animals himself.
Insider could not independently verify if animals had been killed during experiments supervised by Oz. A representative for Oz did not immediately respond to Insider's request for comment.
In his tweet on Tuesday, Fetterman wrote, "BREAKING: Dr. Oz is a puppy killer."
Fetterman continued to slam Oz for most of the day, referencing the content of the Jezebel article in multiple tweets.
"I LOVE my dogs. Apparently some sick people like Dr. Oz get their jollies by harming animals..." Fetterman wrote in another tweet. "We have a close race here in PA and I could use your help to keep the #PuppyKiller out of the US Senate."
Fetterman also retweeted on Tuesday a photo dated May 13 of Oz holding a therapy dog.
"Has anyone seen this dog since May?" Fetterman questioned.
Fetterman has also launched a new piece of campaign merchandise - a 2.5-inch sticker of a golden retriever with the words "Dog Lovers for Fetterman" on it.
Oz did not appear to have responded to Fetterman, per a check of the GOP candidate's tweets on Tuesday night.
Fetterman and Oz have been trading barbs for months. In September, Oz got dragged on Twitter after his insult about Fetterman's fashion sense backfired.
Meanwhile, in August, Fetterman mocked Oz for messing up the name of the grocery-store chain Wegmans and called it "Wegner's" instead. He also accused Oz of carpetbagging and pushed for the Republican to be inducted into the New Jersey Hall of Fame when Oz's tenuous connection to Pennsylvania came to light.