Chaser, the Smartest Dog in the World, Has Died at Age 15

Chaser, known as the smartest dog in the world, died on July 23.
Pilley Bianchi

Chaser joined the family of psychologist John Pilley at just 8 weeks old, embarking on a journey that would change all of their lives.

She was known as the smartest dog in the world. Chaser, a playful border collie who lived in South Carolina, knew the names of over 1,000 items, like stuffed toys and balls. After careful training from her diligent owner, Chaser developed the largest tested memory of any animal. 

Last week, Chaser passed away with her loving humans by her side.

"She really was my little sister," said Pilley Bianchi, whose family raised Chaser.

"She was my buddy. She was my dad's buddy," she told "This was a hard one."

Chaser was born on a farm in Pauline on April 28, 2004. At just 8 weeks old, she joined the Pilley family, embarking on a journey that would change all of their lives.

Bianchi's dad, John Pilley, was a psychologist who taught for decades at Wofford College in South Carolina. He had retired from teaching by the time little Chaser joined the family, but Pilley stepped back into the role with their new pet. After reading about a German dog named Rico who was trained to recognize 200 items, Pilley wondered if he could train Chaser to do the same — and more.

Mark Olencki, courtesy of Wofford College

Using a dog training technique he developed, Pilley began working with Chaser every day. He'd show her a toy, repeat its name dozens of times, hide it and tell her to find it, continuing to say its name while she looked. Within three years, Chaser developed a vocabulary of 800 cloth animals, 116 balls, 26 Frisbees and many plastic items, the New York Times reported.

"His goal was to teach her human language and concepts," Bianchi said, explaining that focusing on language instead of behaviors allowed Chaser to develop a "creative process and make her own choices."

It was this training, combined with Chaser's nature as a working dog breed, that helped her transcend what was previously known about the mind of a dog. And Bianchi said even people at home can do the same with their pets.

"All dogs can do this," Bianchi added. "He believed that there will be a world of Chasers."

Chaser's "affinity for language" stretched beyond her toys, Bianchi said. She even learned the names of all the other dogs in her neighborhood. As the family rattled off the pets' names, Chaser would growl at certain names and wag her tail to others.

"She definitely had her preferences," Bianchi said. But Chaser always kept her cool on walks. "She was too polite, as a proper Southern dog." Chaser would just head in a different direction.

As Bianchi said, Chaser and Pilley were pals. Chaser always wore a collar that was purple, Pilley's favorite color. And every morning, the two would get in a good workout together at the Wofford College gym.

Pilley died in June 2018 at the age of 89. 

"My father constantly emphasized that he learned infinitely more from Chaser than she did from him," Bianchi said. "Dogs are really the unicorn species when it comes to interacting with humans."

She added that her dad "wanted people to understand that we have to have more unity with nature. Humans are not at the top of he intellectual ladder. [Dogs] have geniuses we don't have."

When asked what she'll miss most about Chaser, Bianchi said, "Just her innate joy, her happiness. She was always happy. Her sparkle was infectious."