The announcer’s voice broke the silence that had fallen over the racetrack: “Here comes Spunky!”

As a white, fluffy object, supposed to look like a hare, shot past the starting box, a line of eight greyhounds burst out, a blur of canine energy rocketing down the straightaway.

Such races were once a familiar sight across the country, as bettors flocked to tracks in 19 states, from Florida to Massachusetts to California. At its height, in the 1980s and early 1990s, dog racing drew tens of millions of spectators, routinely posting higher yearly attendance figures than hockey or tennis. Spectator bets totaled roughly $3.5 billion every year.

But today only two dog tracks remain, down from more than 60. Both are in West Virginia, the only state where commercial races still take place. Attendance has waned as pressure from animal rights groups led many states to ban dog tracks and as the legalization of sports betting nationwide gave people a bounty of new gambling options.

Now a bill is making its way through Congress that would ban dog racing altogether. Fans and critics agree that the sport is on its final lap.

“I know at some point, it’s going to end,” said Ronald Welch, who was sitting at a picnic table last month at the track in Wheeling, W.Va. “But still I’d be heartbroken if it did.”

Public sentiment about greyhound racing had already started shifting by the early 2000s, due in part to the efforts of Carey Theil and Christine Dorchak.