The Boston City Council could vote as early as Wednesday on a proposed and now fast-tracked measure that would ban pet stores from selling puppies, kittens and rabbits raised by large commercial breeders - and ban everybody from selling pets by the side of the road.

At a hearing this morning, ISD Commissioner William Christopher praised City Councilor Matt O'Malley's proposal, which would make Boston the first Massachusetts community to ban such sales, but said he is already looking at taking the regulations even further, by trying to regulate people who breed animals for sale in their homes in Boston.

Meanwhile, City Councilor Mark Ciommo of Allston/Brighton vowed to vote against the measure unless a way is found to grandfather the Pet Store on Harvard Avenue in Allston, whose owner, Jim Gentile, sells rabbits he breeds himself. The Pet Store is currently the only store in the entire city that would be immediately affected by the proposed "puppy mill bill."

"I just can't support it when it's targeting one person," especially not a person who he said has been a valued member of the Allston business community for 40 years, he said.

Ciommo added he feels the measure as written would only encourage a black market in pet sales and that he would object to any vote on Wednesday because councilors have not had a chance to study the measure in depth and comment on it - O'Malley introduced the proposal only last week.

Officials from both the MSPCA and the Animal Rescue League of Boston, however, both strongly supported the measure, which they said would be another step towards protecting consumers who may not realize the pets they're buying from pet stores are sick or traumatized - and would especially help protect animals by reducing demands for pets bred in inhumane factories in the Midwest, in particular in Missouri.

Pet stores would still be free to sell puppies, kittens and rabbits obtained from local animal shelters. Mary Nee, Animal Rescue League president, says her group now works with Petcos in Norwood and Dedham to offer such pets to customers.

One staffer at the MSPCA's Angell Animal Medical Center testified with the help of Hope, a sick puppy whose initial owners bought her for $500 in the parking lot of an area Wal-Mart - and who soon gave her up to the MSPCA, which she said has now spent $1,000 trying to diagnose, so far unsuccessfully, what is wrong with her.

O'Malley said he could no longer simply ignore the "large factories that breed animals as if they were cogs on an assembly line."

Amanda Kennedy, Boston's director of animal care and control, said equally important would be to give city inspectors and police a way to punish people found selling pets out of the backs of trucks - or, as in one recent case, out of a duffel bag in Downtown Crossing.

Chistopher, her boss, added that he wants to see a phase 2 to the proposal - in which his inspectors could gain the right to ensure that pets actually bred in Boston are humanely treated. He did agree with Ciommo that any such ordinance would face the same issue as the city's current ban on more than four students living together - what to do if a property owner refuses to let an inspector onto his or her property.

Christopher said that at present, his inspectors have no authority to inspect pet stores or breeders.

He added he would also like to see regulation of some sort of dog walkers, who currently do not have to show any evidence of ability to handle several dogs at once.

O'Malley's proposal calls for fines for anybody found selling puppy-mill animals.