Weary of mending the mauled victims of dog attacks, doctors and nurses looked back at 15 years of serious bite injuries treated at University Hospital and produced a study likely to offer new ammunition for those looking to ban or regulate pit bulls.

They found that attacks by pit bulls were more likely to kill people than those by other breeds. In fact, all three deaths seen at the hospital during the period — two children and a 90-year-old man — were from pit bull attacks, records showed. A fourth fatality wasn't seen at the hospital, a 64-year-old Von Ormy man also killed by a pit bull, death records show.

In addition, they found that pit bulls caused more serious injuries — injuries more likely to put their victims in the hospital. Once admitted, those victims rang up higher medical costs.

“Fortunately, fatal dog attacks are rare, but there seems to be a distinct relationship between the severity and lethality of an attack and the breed responsible,” they wrote in an article published in the April issue of the medical journal Annals of Surgery. “These breeds should be regulated in the same way in which other dangerous species, such as leopards, are regulated.”

Advocates, dog owners and some experts disagree. They argue passionately against singling out pit bulls, saying the problem is one of irresponsible owners, not an irredeemable breed. People often confuse pit bulls — a generic term for various bull terrier breeds and mixes — with other kinds of dogs, making statistics suspect, they say.

The study began two years ago when a series of attacks in the area led to renewed calls for regulating pit bulls. Lawmakers in Austin considered bills permitting local bans on specific breeds, which now are forbidden under state law. None passed.

The study's authors argue that pit bulls deserve the special attention they get. Pit bulls, originally bred as fighting dogs, have different attack patterns than other breeds, they say — attacking indiscriminately, without warning and, often, with little interest in stopping.

“There are going to be outspoken opponents of breed legislation, who say: ‘My pit bulls lie with my baby and play with my rabbit.' And that's fine,” said Dr. John Bini, now chief of surgery at Wilford Hall Medical Center, who led the study while serving a fellowship at University Hospital. “I just think we're seeing something here, and I think it does warrant a discussion as to whether this is a risk that a community wants to take.”

Among the grisly statistics the study cites: Pit bulls were responsible for 65 percent of all fatal dog attacks nationally in 2008. In Texas in 2007, seven fatal attacks occurred, six involving pit bulls. Someone in the United States is killed by a pit bull every 14 days. One body part is severed and lost in pit bull attacks every 5.4 days.

Dr. Bonnie Beaver, a professor of veterinary medicine at Texas A&M University and an expert in dog behavior, described the study as flawed. Beaver, a former president of the American Veterinary Medicine Association, who led a national task force on preventing dog bites, has testified against breed-specific bans before state lawmakers.

“These are serious injuries to humans, and I do not mean to belittle the seriousness of the problem seen at the hospital,” Beaver said. “However, the dog-related data is seriously flawed, and are used at will to try to prove a specific point of view.”

A public health hazard

Seven-month-old Izaiah Cox was sobbing in the bedroom. His great-grandmother, Irma Garcia, was in the kitchen preparing a bottle to sooth him. So were her two dogs, Cain and Wrinkles — even though the boy's parents had asked her not to allow them inside while she was babysitting.

Izaiah's father had gotten both dogs as puppies from the same litter a decade earlier, but Garcia soon assumed responsibility for them. She described them as her babies, and said they were protective of her — especially when she was sick.

Garcia, 59, had a doctor's appointment that morning in early 2009, and was waiting for her daughter to come and drive her. What happened next isn't clear. A detective's report said one of the dogs apparently pulled the boy from the bed. Garcia, unable to get him loose, grabbed two kitchen knives and began stabbing the dogs.

Somehow she pried the dog's jaws apart, receiving bites on her hands; put the child in the playpen; and herded the dogs out the front door.

Her daughter, who lived nearby, received a telephone call and heard her mother screaming “Stop!” repeatedly, she told police. She drove there and saw the bloody dogs in the yard, ran past them into the house and found her mother crying hysterically. When she asked what happened, her mother said, “They got Izaiah,” and pointed toward his playpen.

The daughter called 911 and advised the dispatcher that police would have to shoot the dogs to get inside, which they did. Her mother protested. According to the detective, the daughter angrily replied that she didn't care if police shot the dogs because her nephew was dead. Police later learned that Garcia's dogs had bitten a niece on the face two years earlier, and had bitten others. Garcia was indicted for serious bodily injury to a child. She died before the case could go to trial.

The morning after pronouncing Izaiah dead, veteran trauma surgeon Dr. Stephen Cohn sat in his office and shook his head at the dozens and dozens of bites the boy had sustained.

“I think this is a public health hazard, this particular dog,” said Cohn, professor of surgery at the University of Texas Health Science Center. “We just have to have them contained in a way that protects the general public. I don't want to see another kid come in dead.”

Incomplete data

Cohn first had the idea for the study a couple of weeks earlier, after treating a man whose leg was mauled by four pit bulls. He assigned Bini the job of pulling patient records — 228 over 15 years — to analyze. Only those serious enough to be admitted to University Hospital, the city's main trauma center, were included. And although Izaiah's death gave the study some urgency, Bini's orders were to approach the job dispassionately.

He found breed information on 82 of them, either recorded in the patient records or from bite investigation reports at Animal Control Services. Of those, 29 — or 35 percent — were listed as pit bulls or pit bull mixes. While no other breed is broken out in the study, Bini said pit bulls made up the largest category.

Bini acknowledged the small percentage of identified breeds was a weakness in the study, one that other experts pointed out.

“Data on breed only came from 36 percent of cases, so how can you say any breed is more dangerous when you have incomplete data?” Beaver said.

Beaver headed a national veterinary task force on canine aggression. Its 2001 report on preventing dog bite injuries warns against lending credence to dog bite statistics.

“Invariably the numbers will show that dogs from popular large breeds are a problem,” the report stated. “This should be expected, because big dogs can physically do more damage if they do bite, and any popular breed has more individuals that could bite.”

But how popular are they? To truly measure a breed's aggression, Bini believed, it would help to know what percentage of dogs are pit bulls, and compare that to the number of fatal attacks. That estimate wasn't available locally.

Failing that, he got national numbers for registered breeds from the American Kennel Club and compared it to a list of fatal dog attacks by breed across the country, collected by an independent group based on media accounts.

Labrador retrievers are the most popular registered breed. Using that as a rough measure of the popularity of all Labradors — purebred and mixed-breed, registered and not —the breed had the lowest risk of killing someone. Pit bulls — a category that combined American Pit Bull Terriers, American Staffordshire Terriers and Staffordshire Bull Terriers, ranked 11th in popularity among 16 AKC-registered breeds and had by far the highest risk of killing — more than 2,500 times higher than Labs.

Beaver was particularly critical of that estimate, saying few pit bulls are registered or purebred. Bini agreed, but noted that neither are most Labs.

Dr. John Herbold, a veterinarian and retired professor of epidemiology at the UT School of Public Health, also felt that the study suffered from small numbers and other problems. But he sympathized with the authors' intent.

“I believe their hypothesis, that there are certain breeds that are more likely to be involved in these deadly events,” Herbold said. “I believe that. And the troubling thing that they revealed in here was that in many cases, these animals were members of the household or a family member's. It wasn't a mad dog, roaming the street.”

‘Changing pits image'

So far, owners have successfully lobbied against breed-specific legislation in Texas, organizing letter-writing campaigns and beating back attempts that arise anytime there's a high-profile attack. Still, within the bounds of their authority, local officials have prosecuted owners of dogs that attack under existing laws. And ACS requires a home visit by its investigators before allowing pit bull-type dogs to be adopted, unlike with most other breeds, spokeswoman Lisa Norwood said.

Sherise Davila heads a nonprofit group here called Heaven Sent Pit Bull Rescue that last year took in 82 unwanted dogs, rehabilitated them and found them new owners — six of them as service animals.

But her group's real purpose lies in its motto: “Changing pits' image one pit at a time.” Pit bulls have gotten a bad reputation not because they're inherently bad, she said, but because they're often the first choice of bad owners.

“Some people tend to get this dog because they're missing something inside themselves,” she said. “They'll never know the true friendship or love of that animal, because the way they treat that animal they're never quite sure what it's going to do.”

The first step is lots of love and praise, she said. Then comes a battery of tests to determine the animal's level of aggression and personality. An individual schedule of training is designed, one that always includes plenty of contact with other dogs. A few are selected for additional training as military dogs or search-and-rescue or special companion animals. That includes Pluto, Davila's own dog. Davila suffers from a seizure disorder, and not only is the dog trained to sense when she's about to have a seizure and signal her, but he can fetch her medication bottle from the bathroom.

“When Pluto got here, he was not the most well-behaved dog at all,” she said. “Temperaments can be changed. You have to be able to put the time and work in to change it.”

Bini isn't so sure. “That will be the argument that a lot of people have, that it's not the dog. It's the owner. But I think you really have to throw the emotion out. Yeah, it's emotional. But throw it away and let's look at our data.”