THE BLOODY paw prints were still in the snow, and a bunch of white gauze lay nearby.

The pinkish snow was packed down where two pit bulls had attacked a 10-year-old boy - severely injuring his right arm and puncturing his neck, left arm and back with their teeth shortly after 11 a.m. yesterday.

The child had been walking with two boys who had both dogs on leashes. The dogs - one brown and the other white with brown spots - began fighting each other, then turned on the 10-year-old, said Capt. Ben Naish, police spokesman.

It was the third vicious pit-bull attack in Philadelphia in three days.

On Friday, a victim's wrist was nearly severed. On Saturday, a woman was mauled to death. And last night, doctors were trying to save a little boy's arm. All three attacks involved dogs known to the victims.

The latest assault took place in snow-covered center field of a baseball diamond in Whitehall Commons, known as "The Home of the Frankford Chargers," at Wakeling and Jackson streets in Frankford. The field in behind Warren G. Harding Middle School on Erie Avenue near Wakeling.

The child, whose name police withheld, was taken to St. Christopher's Hospital, where he could provide police with only a few details before being hurried to hours-long surgery to save his arm, Naish said.

Last night, the child was listed in critical but stable condition. His parents were with him, he added.

Witnesses told police that they thought the dogs had been playing with a trash bag, said Naish, but apparently it was the child's arm.

Neighbors heard the dogs barking and called police.

The two boys got control of their dogs and left before police, a medic unit and fire truck arrived.

"I'm sure the boys are very worried," said Naish.

Two Northeast detectives stood with Naish outside St. Christopher's, where Naish appealed to the boys and their parents to come forward and call Northeast Detectives at 215-686- 3153.

"Right now, we have a severely injured young boy, and we're trying to get to the bottom of this," he said. "The detectives need to talk to everyone.

"This is malicious. This is sad, but there doesn't seem to be anything criminal here," he added.

The first pit-bull attack of the weekend came at 4:28 p.m. Friday, when a 52-year-old woman was mauled inside her home on Front Street near Tabor Road, North Philadelphia, by a dog that belonged to another resident of the house, police said.

The woman's left wrist was nearly severed in the attack. She was taken in serious condition to Albert Einstein Medical Center, where she remained hospitalized last night, according to police.

The SPCA's Animal Care and Control Team took custody of the pit bull, police said.

In the second attack, Barbara Erb and her daughter Christine Staab, 38, were arguing in Erb's Fishtown home early Saturday, when one of Erb's six pit bulls attacked Staab, according to police.

Police and medics were called at 7:09 a.m. to respond to the rowhouse on Oxford Street near Frankford Avenue for reports of a person screaming.

Erb was unable to stop the dog from clamping down on her daughter's throat, and the dog was still attacking Staab when medics arrived, police said.

The attack was stopped only after responding police officers shot the dog to death. After the shooting, a second pit bull charged the cops, prompting them to kill that animal too, police said.

Staab was pronounced dead at 7:24 a.m. in her mother's home.

The remaining four pit bulls were removed from the home by the SPCA's Animal Care and Control Team and were placed in quarantine, where they remained yesterday, according to an SPCA spokeswoman.

East Detectives was leading the investigation and SPCA officials are awaiting word from the police to determine whether the dogs will be released to Erb or remain at the shelter, the spokeswoman said.

An East Detectives supervisor yesterday said he wasn't aware if charges would be filed against Erb, but said that the District Attorney's Office had called and asked for the file and would be investigating.