NAPERVILLE, Ill. (CBS) — An attorney who is suing a chain of pet shops says it could turn into a class-action case.

As WBBM Newsradio’s Regine Schlesinger reports, Ed Clinton represents half a dozen plaintiffs so far who say they were misled by the Happiness Is Pets stores, including the location in Naperville.

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LISTEN: WBBM Newsradio’s Regine Schlesinger reports

They say the dogs they bought at the pet shop turned out to have serious problems – particularly the incurable viral infection distemper.

Clinton says he expects to hear more complaints from other customers and is seeking class-action status on the lawsuit.

“We’ve been contacted by many people, but we have to go through a process of vetting them and sorting out whether they are appropriate class members,” Clinton told the Naperville Sun last week, adding that he is working to establish how many cases of canine distemper can be traced to the pet shop. “I think that distemper is the main issue.”

David Fish, the attorney representing the store owner, said the lawsuit “has no merit” and believes it will be dismissed.

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Owner Ron Berning has emphasized that the illnesses constitute “an extremely isolated incident,” and expressed confidence that the problem was caught early.

“We were assured by our veterinarian that we have exceeded the time period for incubation and that no puppies in the store are affected,” Berning wrote in an email Jan. 23.

So far, there have been four complaints about puppies from Happiness Is Pets having distemper. One of the puppies died.

The Wilson family of Downers Grove reported that Lily, a 4-month-old yellow Labrador they had purchased at the pet shop, succumbed Jan. 9. Three other puppies believed to be impacted by the outbreak at the store are recovering from the highly contagious and sometimes fatal virus.

The Naperville Sun contributed to this report, via the Sun-Times Media Wire.

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(Source: Sun-Times Media Wire © Chicago Sun-Times 2012. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)