A bill that would put more bite into federal regulations governing wholesale dog and cat breeding facilities will come up for discussion tomorrow in the U.S. Senate.

The proposed legislation is officially called the Pet Animal Welfare Statute of 2005. It is commonly referred to as the PAWS bill by its many supporters and opponents.

U.S. Sen. Rick Santorum, R-Pa., will chair a hearing before the U.S. Senate Agriculture Subcommittee on Research, Nutrition and General Legislation. Mr. Santorum is co-author of the PAWS bill, with Sen. Richard Durbin, D-Illinois.

PAWS is "bipartisan legislation" aimed at addressing "the lack of regulatory oversight that has allowed some in the pet industry to operate below the acceptable care standard for pets," according to a news release from Mr. Santorum.

The subcommittee hearing, which is open to the public, will be held at 2:30 p.m. tomorrow in Room G-50, Dirksen Senate Office Building, in Washington, D.C.

Seven "witnesses" will testify at the hearing.

Four witnesses are identified as members of the "animal interest group panel." They are Ron Menaker, chairman of the American Kennel Club; Dr. Henry E. Childers, president of the American Veterinary Medical Association; John E. Hoffman, "dog fancier"; and Michael Maddox, legislative director of the Pet Industry Joint Advisory Council.

Witnesses on the "animal welfare group panel" are Wayne Pacelle, president and chief executive officer of the Humane Society of the United States; Sara Amundson, legislative director of the Doris Day Animal League; and Norma Worley, director of the animal welfare program, Maine Department of Agriculture.

The PAWS bill is commonly viewed as taking aim at so-called "puppy mills," which are generally described as large commercial breeding facilities that produce hundreds, or even thousands, of puppies and kittens every year. Opponents say that animals raised in those facilities have health and temperament problems.

The U.S. Department of Agriculture regulates and inspects some breeding facilities. Some states, including Pennsylvania, also mandate inspections of some breeding facilities.

Existing federal regulations only cover wholesalers.

PAWS, according to Mr. Santorum, would bring under government regulation some breeders who sell directly to the public, including those who sell puppies and kittens on the Internet.

A 2001 version, also backed by Mr. Santorum, was known as the Puppy Protection Act. It was sunk by opposition from many quarters, including sportsmen who breed hunting dogs and so-called "hobby breeders" or "show breeders" who breed cats and dogs to compete in shows.

Mr. Santorum and his staffers have met with dozens of organizations and individuals to modify the proposal. Supporters of PAWS now include the American Kennel Club, which registers purebred dogs and sanctions dog shows and other competitive events; the national Humane Society; People for the Ethical Treatment of Animals; and the Doris Day Animal League

Opponents include many show and hobby breeders, the Cat Fanciers' Association, the U.S. Sportsmen Alliance, The United Kennel Club and the American Dog Owners Association.