(CBS) – Two loose pit bulls attacked another dog that was being walked by its owner earlier this week, police in southwest suburban Riverside say.

Police responded to emergency calls Thursday morning in the 400 block of Selborne Road. There, they found a miniature collie bleeding from its ear. Officers learned the owner had been walking the pet past a property when two pit bulls running free in a backyard attacked.

The owner of the pit bulls, a Chicago man whom police did not identify, was ticketed under a village ordinance for having a dangerous or fierce dog unleashed.

“I strongly encourage dog owners to have their pets on a leash at all times and under their control. Additionally, dogs should only be let out into rear yards unleashed when that yard is completely fenced in and there is no danger of the dog escaping,” Riverside Police Chief Thomas Weitzel said in a news release.

The collie was treated at a veterinarian’s office and returned to its owner, police said.