Say the words “Westminster Dog Show” and most people picture the same thing: a perfectly groomed purebred trotting a triangle while a judge assesses how closely it matches an ideal written down in a breed standard. So there’s a satisfying twist in the fact that, in 2024, the fastest dog at Westminster wasn’t a champion of any breed at all. She was a mutt.
Her name is Nimble, and at the 11th annual Masters Agility Championship she did something no mixed-breed dog had ever done at the event: she won the whole thing. A six-year-old Border Collie–Papillon mix, she cleared the course in 28.76 seconds, the fastest run in a field of 350 dogs. That run made her only the fifth dog ever to break the 30-second barrier at Westminster, and the third-fastest competitor in the event’s history. She is, for the record, also extremely charming to watch, all floppy black ears and blur.
Why this was a first, and why it matters
Agility is Westminster’s great equalizer. The show is famous for its conformation events, where dogs are judged against breed standards and the ultimate prize, Best in Show, goes to the dog that best embodies its breed in looks and temperament. By design, a mixed-breed dog can’t win that. The Masters Agility Championship works differently. It’s open to any dog, including mixed breeds, which the American Kennel Club calls All-American dogs, and it rewards one thing only: getting through a course cleanly and fast.
Mixed breeds have been eligible for the agility championship since it launched in 2014. But eligibility and victory are different things. Purebreds, especially Border Collies, have dominated the podium, and until Nimble, no All-American had taken the overall title. Twenty-six other mixed-breed dogs competed alongside her that year, and she was the best of all of them and everyone else.
“Agility strips the sport down to what a dog can actually do, not what it’s supposed to look like on paper,” says Marcus Webb. “A course doesn’t care about your pedigree. Nimble winning isn’t a fluke or a feel-good asterisk, it’s the event working exactly as intended, and it’s a reminder to anyone scanning shelter kennels that the dog that outruns the field might be sitting right there.”
The company she keeps
Nimble’s win sits inside a run of serious dominance by one type of dog and, it turns out, one handler. Border Collies had taken eight of the first 11 championships, with a Shetland Sheepdog and an Australian Shepherd winning in 2016 and 2022. Nimble’s handler, Cynthia Hornor, was on a streak of her own: the year before, her Border Collie Truant won the same championship with a nearly identical time of 28.68 seconds. Two years, two winners, one handler, which says something about training as much as breeding.
The Westminster Kennel Club notes that the most common breeds in agility competition are Shetland Sheepdogs, Belgian Tervuren, Border Collies, Golden Retrievers, Labrador Retrievers, Cocker Spaniels, and Papillons, a lineup heavy on herding and working dogs bred for exactly the kind of drive agility demands. Nimble, as a Border Collie–Papillon cross, is a walking argument that those traits don’t require papers to show up.
What happened next
Nimble’s milestone didn’t turn into a mixed-breed takeover, but the door she opened has stayed open. At the 2025 championship, a Border Collie named Vanish took the top prize, handled by owner Emily Klarman. In 2026, the overall title went to another Border Collie, Prove-It, while the highest-scoring All-American honor, the best-mixed-breed award Nimble helped make famous, went to a five-year-old mutt named Iron Man, who posted the fastest clean round of his group at 29.60 seconds.
The pattern is telling. Purebred herding dogs still win most of the marbles, because agility rewards the exact drive they were bred for. But the All-American category is now a real, contested part of the event, and every year a shelter-type dog gets the national spotlight for outrunning dogs with far fancier resumes. That’s the quiet legacy of Nimble’s 28.76 seconds: not that mutts now win everything, but that nobody’s surprised anymore when one shows up and can.
