A long-standing attempt to end pet-breeding facilities known as puppy mills is standing on stronger legs this summer because of recent changes that have won the support of one of the country's most influential animal welfare organizations.

A bill pending in the U.S. Senate would put more bite into the U.S. Department of Agriculture regulations that cover the breeding facilities of dogs, cats and some other animals, and it would widen the net of sellers and breeders who would be bound by the rules.

And, unlike an earlier version introduced in 2001, the Pet Animal Welfare Statute or PAWS, has the support of the American Kennel Club, an organization that registers purebred dogs and sanctions dog shows. That backing could give PAWS the push it needs to win congressional approval and become the law of the land, many opponents and supporters think.

Existing regulations cover only wholesalers; most retail pet store puppies and kittens come from large-scale commercial breeders who sell at wholesale.

The proposed legislation -- introduced May 26 by U.S. Sens. Rick Santorum, R-Pa., and Richard Durbin, D-Ill. -- would bring under government regulation some of the breeders who sell directly to the public, including those who sell kittens and puppies on the Internet. Santorum says many of them are "high-volume dealers ... evading regulation" because their sales are retail, rather than wholesale.

PAWS would amend the Animal Welfare Act, which is enforced by the U.S. Department of Agriculture "to protect certain animals from inhumane treatment and neglect," according to the USDA Web site. PAWS would "strengthen the ability of the secretary of agriculture to regulate the pet industry," according to language in the proposed bill.

The Animal Welfare Act mandates "minimum standards of care and treatment" for warmblooded animals "bred for commercial sale, used in research, transported commercially or exhibited to the public." Farm animals are not covered and neither are coldblooded animals such as reptiles.

Federal regulations mandate that animals have adequate housing, handling, sanitation, nutrition, water and veterinary care.

Some of those guidelines include these provisions:

Animals raised in cages or kennels must have enough room to stand up, sit down, turn around and "make normal postural adjustment."

Veterinary care must be provided, and records of care must be kept and shown to federal inspectors who ask.

Dogs must get exercise. Dealers, exhibitors and research facilities must have an exercise program approved by a veterinarian.

Dogs and cats must be fed at least once a day, and the food should be uncontaminated and wholesome.

Excretion and food waste must be cleaned up at least once a day.

Some of the regulations are somewhat vague, and compliance is up to the discretion of the federal inspector.

Nationwide, the USDA has 95 inspectors who enforce the regulations. They make about 10,000 inspections a year. Only a handful of states, including Pennsylvania, have regulations governing commercial breeders, which is why many animal rights and animal welfare groups are pushing for more federal regulation and supporting PAWS.

The regulations apply to all large-scale commercial breeders, and the aim is to eliminate the ones derisively called puppy mills, those that keep large numbers of animals confined to cages and kennels, provide little exercise or interaction with other animals or people and breed females too often.

Animals coming from such facilities frequently have significant health and behavior problems that make them unsuitable pets.

The proposed bill would begin regulating Internet sellers.

Santorum said it also would:

Help the Agriculture Department identify violators by making those who acquire animals for resale keep records of where they got the animals.

Give federal officials the power to suspend a dealer's license for up to 60 days if violations place animals in imminent health danger.

Strengthen the department's authority to obtain injunctions to shut down dealers who fail to comply with the law.

People who breed fewer than 25 puppies or kittens per year or fewer than seven litters per year would not be bound by the regulations.

Santorum says his interest in this issue is twofold.

He's an animal lover whose family's "beloved German shepherd dog Schatzie" was purchased two years ago from a small breeder.

And he knows animal rights and animal welfare groups rank Pennsylvania among states with the most and some of the worst puppy mills, especially in Lancaster County and surrounding areas. He says it's "not something I'm particularly proud of."

PAWS supporters at this time, including the AKC, are People for the Ethical Treatment of Animals, Humane Society of the United States and the Doris Day Animal League, which has been lobbying for this type of legislation since 1990.

The first attempt at this legislation, called the Puppy Protection Act when it was introduced in 2001, was sunk by protests from many groups that represent people who own, love and, in some cases, breed, cats, dogs and other animals.

Some of the most vocal opposition came from breeders of small numbers of purebred dogs and cats, sometimes called hobby breeders or show breeders, and from sportsmen who buy, sell and train hunting dogs. One of their arguments was that they do not make a profit raising and selling animals and, therefore, should not be subject to government regulations, fees and inspections.

The American Kennel Club opposed that version because it felt it did not differentiate between breeders who make a profit selling large numbers of animals and people breeding small numbers for no profit, said Daisy Okas, vice president of communications at the AKC.

Those who remain opposed to the current bill include the United Kennel Club, American Dog Owners Association, the National Animal Interest Alliance, Cat Fanciers' Association and the U.S. Sportsmen's Alliance.

Opposition also is rampant in small rescue groups made up of people who take in homeless animals and care for them until they can place them in new homes. Because they charge adoption fees to cover their expenses, they fear they will be viewed as sellers who fall under federal regulations, although Santorum says they wouldn't.

PETA, which has the most extreme position and opposes all animal breeding, supports PAWS, though that group preferred the earlier, tougher version. PETA investigates reports of abuse and neglect in puppy mills "where they churn out puppies as if they are widgets," PETA spokeswoman Laura Brown said.

Sportsmen are concerned that PAWS "will impact traditional folk who breed a few litters a year," said Tony Celebrezze, state services director for the U.S. Sportsmen's Alliance. "You could call it a slippery slope," he said.

"If Sen. Santorum is trying to go after puppy mills, there has to be an easier way of doing it. If he is concerned about the Internet, he should go after people who sell on the Internet."

Santorum and his staff have met with dozens of groups and "have literally bent over backward to craft a bill that does no harm," Santorum spokesman Jeff Stolsfutz said.

And the bill may face further tweaking.

Next month, Santorum expects to schedule a hearing "to make technical corrections and to clarify some of the bill's language"