BRECKENRIDGE, Colo. — A push to stop pet stores from selling dogs from puppy mills appears to be gaining traction in Colorado.

In June, Berthoud became the first city in Colorado to ban pet stores from selling animals from puppy mills and Breckenridge followed suit this Fall. neither city has pet stores operating within city limits.

“Most people don’t know what goes on in these puppy mills,” Joyce Cohen, animal advocate from Breckenridge, said.

Puppy mills are defined as “inhumane commercial dog breeding facilities.” According to the Humane Society of the United States, that often means a dog’s health is disregarded for the purpose of breeding as many dogs as possible.

The Humane Society of the United States estimates there are 10,000 licensed and unlicensed puppy mills operating across the country.

“Colorado is also really progressive,” Cohen said.

Cohen, a retired lawyer, who initially lobbied Breckenridge City Council to pass an ordinance banning the sale of puppy mill puppies, is making it her mission to get other Colorado cities to do the same.

“So far, I’ve been to all the towns in Summit County,” Cohen said.

City leaders in Dillon are discussing a similar proposal on Tuesday. Dillon officials say there is a first and second reading of the proposed ordinance already scheduled in November. Cohen has met with city leaders in Eagle County, as well.

“Anybody can go to a city council meeting,” Cohen said. “My brother has been doing this in New Jersey.

Joyce Cohen’s brother, Larry Cohen, is a volunteer legislative coordinator for the Humane Society of the United States. He said he’s helped pass more than two dozen ordinances banning the sale of puppy mill dogs in cities across New Jersey.

“These ordinances are so benign in terms of who they are going to hurt,” he said. “Every time a puppy mill sees another town that has said, we don’t want to do business with you because of the way you do business. I think there’s always a tipping point.”