The Westminster Kennel Club dog show has long been the province of purebreds. But the nation’s premier canine event is opening a doggie door this year to mixed-breed competitors: They’ll be included in its new agility trial.

Next month’s show at Madison Square Garden will also feature three new breeds. They’re the chinook, the Portuguese podengo pequeño and the rat terrier.

A press conference Wednesday featured some of the newcomers, plus dogs weaving around poles and jumping through a tire on an agility course.

Organizers say this year marks the first time dogs of mixed breeds have appeared anywhere at Westminster since the 138-year-old event’s early days.

They won’t vie for the prestigious Best in Show award. That’s still purebreds only. It’ll be awarded on Feb. 11.