NEW YORK — They’re at the top of their sport. They’re primed to run down tennis balls. So perhaps it’s perfectly natural that about 3,000 top-flight canines are converging on the grounds of the U.S. Open tennis tournament, where the Westminster Kennel Club dog show began Saturday.

It’s a new venue for the nearly 150-year-old event, now back in New York City after a two-year, pandemic-induced sojourn in the suburbs.

As the show began Saturday with an agility competition and other events, there were a …