DUBUQUE, Iowa — Vera Rasnake laughed as she led a trio of barking, jostling dogs into the Iowa Greyhound Park, but her smile faded when she acknowledged that after 41 years of being around the sleek animals, her sport was teetering on extinction.

After the end of a truncated season in Dubuque in May, the track here will close. By the end of the year there will only be two tracks left in the country.

“It’s very hard for me to see this,” Rasnake said.