Three men were charged Wednesday, including the day care operator's husband, and authorities were seeking two others. Authorities had initially said four people had been arrested.
Nine battered dogs — four of which were puppies — were rescued, police said.
"The dogs were in horrific condition," Cook County Sheriff Tom Dart said at the Animal Welfare League in suburban Chicago Ridge, where several of the dogs were undergoing surgery and rehabilitation. "This is as bad as we've seen."
He described a gruesome scene in the day care's garage, with blood all over the floor and a car. Police also found items such as syringes, bite sticks and a treadmill that had been altered to be used specifically to train the dogs. Officers also recovered a 1996 edition of "Sporting Dog Journal."
Dart said approximately 10 children were found in the day care during the raid Tuesday, but they were not in the immediate vicinity of the dogs.
Illinois Department of Children and Family Services spokesman Kendall Marlowe said the Maywood day care was shut down Wednesday and was under investigation. He said it had been licensed since March 2004 and for a capacity of seven children.
He said two complaints were received — in 2006 and 2007 — about dogs at the home. But after DCFS officials made unannounced visits, dogs were only found locked in the garage and not near children.
Marlowe said the day care operator agreed to a plan to keep dogs from the day care areas of the home.
"This day care home is now closed, and we will monitor the home going forward to ensure that it does not reopen," Marlowe said in a statement Wednesday.
Dart said the day care operator told police that she was not involved in dog fighting and that children were never near the dogs or dog fighting equipment. Day care officials could not immediately be reached.
Neighbor Glenn Durias said he saw a male resident at the house walk the dogs and give them commands, but never saw them act violently or be close to children.
"I've never seen the children and the dogs interact with one another," he said.
Officers had raided the Maywood day care and two other nearby homes on Tuesday to rescue the dogs. On Wednesday, Dart cradled one cream-colored 8-week-old puppy that was missing an eye and had scratches on its face.
"The dogs had been thrown into fights," he said.
Linda Estrada, president of the Animal Welfare League, said the dogs were being evaluated.
"We're going to fatten them up, give them love and care," she said. "Then they will go up for adoption."