CHICAGO (CBS) — An attorney for small pet stores in Chicago was vowing to appeal a recent court ruling tossing out a challenge to the city’s puppy mill ordinance, and threatening a defamation lawsuit against advocacy groups he accused of lying to get their way.

City Clerk Susana Mendoza said last week’s court ruling, which cleared the way for the city to begin enforcing its so-called puppy mill ban, was a huge victory.

“I know maybe it doesn’t seem like a big deal, but it really is,” she said after Thursday’s ruling dismissing a lawsuit seeking to strike down the ban. Mendoza sponsored the ordinance, which was approved by the City Council in March 2014, and slated to take effect a year later, but was not enforced while a lawsuit challenging the measure was pending.

Attorney Sean Patrick agreed the judge’s ruling was a big deal, but for different reasons. He represents the Park Pet Shop in Mount Greenwood and Pocket Puppies in Lincoln Park.

“Let me tell you something. Pocket Puppies, they’re like the Whole Foods of pet shops. They make sure that all their breeders are responsible. They’re typically smaller breeders, and in Park Pet Shop, that’s a mom-and-pop shop. They’ve been working for over 50 years,” he said.

Patrick said neither shop sells puppy mill puppies, but under the city’s ordinance, they’ll likely go out of business.

The city’s ordinance prohibits retailers from selling dogs, cats, or rabbits that do not come from government-run animal shelters, or private humane societies or rescue groups. Unlike a Cook County puppy mill ordinance also enacted in 2014, the city’s rules do not allow retailers to sell animals from any type of breeder.

Cook County’s puppy mill ordinance allows stores to sell animals from federally licensed breeders that have no more than five animals able to reproduce.

Patrick said, not only do the two pet shop owners who sued over the city’s ordinance plan to appeal, they are considering a defamation lawsuit against organizations that sought the puppy mill ordinance, saying his clients have been “tarred and feathered” by being lumped in with stores that deal with puppy mills known for mistreating and overbreeding animals.

He blamed a group of outside non-profit organizations for waging a misleading campaign against retail pet shops.

“They go from city to city. They don’t care about the facts. They assume that every pet shop is the same, and they accuse them all of illegal activity, which is false,” Patrick said.

Patrick said he supports the goal of trying to eliminate puppy mills, as well as rescuing animals from shelters, but he said many people still want to find purebred puppies, which can only be obtained through breeders.

“Let me tell you something. The demand is still going to be there. People are still going to look for purebred puppies, which you do not find at the … for example, you go in to the Anti-Cruelty Society … you’re not going to find any purebreds,” he said.

He said the city’s ordinance will make the problem worse, because people will still seek out purebred puppies, and it will end up happening without proper regulations or licenses if people can’t get purebreds from pet stores that work with responsible breeders.