CORRECTION: This post had been updated to reflect the correction appended at the end.

Colleen Lynn was jogging in Seattle eight years ago when a pit bull knocked her on her back and sunk its teeth into her forearm. She screamed as the pit bull crushed the bone in seconds.

The experience shook her so strongly that she founded DogsBite, an organization that warns the public about breeds it has labeled dangerous. Lynn said she would like to see pit bulls make up no more than 1 percent of the U.S. dog population someday.

A string of five high-profile pit bull attacks in Oregon last fall, which killed two dogs and seriously injured three people, provoked similarly strong emotional responses. The episodes also reignited a longstanding debate over the risks pit bulls pose.

An analysis by The Oregonian/OregonLive of 3,940 Portland-area bite investigations since 2010 shows that authorities have implicated pit bulls in more attacks than any dog breed: 510.

Labrador retrievers, which outnumber licensed pit bulls nearly 5-to-1, were a distant second at 427 bites.

The analysis doesn't capture every dog bite because county regulators only compile information about serious incidents reported to authorities. And when dog bites are reported, the public doesn't always identify the breed correctly.

But in most cases reviewed by The Oregonian/OregonLive, the breed was identified by the dog's owner and not the victim, making it a more reliable observation.

The stakes are high in dog attacks, and not just for victims.

DOG BITES, 2010-2014

Breed Bites Licenses Rate Pit bull 510 4,238 120 Labrador Retriever 427 20,022 21 German Shepherd 278 5,566 50 Chihuahua 231 8,804 26 Australian Shepherd 138 4,420 31 Australian Cattle Dog 122 2,343 52 Rottweiler 117 1,348 87 Dachshund 109 5,166 21 Border Collie 106 3,353 32 Boxer 91 2,353 39 Lhasa Apso 82 2,961 28 Terrier 65 3,007 22 Jack Russell Terrier 65 1,778 37 Golden Retriever 63 5,405 12 Chow Chow 57 568 100 Poodle 56 4,181 13 Siberian Husky 48 1,345 36 Shih Tzu 47 2,839 17 Beagle 37 2,241 17 Pomeranian 35 2,649 13 Pinscher 35 1,035 34 Boston Terrier 34 1,487 23 Doberman Pinscher 31 638 49 Mastiff 30 395 76 Cocker Spaniel 29 1,955 15 Rat Terrier 29 1,133 26 Welsh Corgi 26 1,507 17

More than one-third of all homeowners insurance claims in 2013 were for dog bites, costing a total of $483 million, according to the Insurance Information Institute.

Investigating dog attacks and dealing with dangerous dogs also costs taxpayers. Animal services budgets in the three counties totaled more than $3 million in fiscal year 2015.

Although most bites don't result in trauma, death or hospitalization, they can.

In 2013, about 27,000 people nationally underwent reconstructive surgery after a dog attack. About 800,000 bite victims a year require medical attention, and a few dozen die.

Oregon has had three fatal dog attacks on people since 2007, most recently in September 2013 when a pit bull killed a 5-year-old boy in Baker City.

Pit bulls, although they are not the only kind of dog involved in serious attacks, have become a target nationally.

About 700 cities and counties have reacted to the pit bull's reputation by enacting restrictions on the breed, according to dogsbite.org, which advocates for such policies. Some have banned pits altogether.

"Pit bulls are bred to kill," said Don Bauermeister, who championed a pit bull ban in Council Bluffs, Iowa, 10 years ago. "When a pit bull sees another dog, that's an urge that's hard to overcome."

"We created this canine Frankenstein," he said.

But dog experts and pit bull advocates say breed-specific laws miss the point. Pit bulls are simply the dangerous dog du jour, they say. Banning them amounts to discrimination without basis in science.

Advocates say pit bulls are locked in a vicious cycle. Disproportionately, they attract owners who are likely to mistreat or neglect them. That treatment makes them aggressive, confirming the image people have of them.

The question of who's to blame, pit bulls or their owners, has become a new front in the nation's culture wars. For all the cities that have enacted bans on pit bulls, lawmakers in 17 states have been persuaded by animal welfare groups to prohibit such bans.

The federal government is at odds with itself, too. In 2013, the White House issued a statement against laws banning specific breeds, saying they are "ineffective and often a waste of public resources." Yet the U.S. Army, Air Force and Marines all ban pit bulls and other breeds on their bases.

No Oregon lawmaker has introduced either type of legislation this year, but bills targeting pit bulls have been on the agenda in the past. A proposal that died in the 2009 Legislature would have banned the animals; another would have required pit bull owners to carry $1 million in liability insurance.

Randy Covey, field director for Washington County Animal Services, said the right approach to preventing dog bites is to focus on the owner and not the breed.

"I've seen pit bulls that are a lot more tolerant and a lot more socialized and better behaved than labradors," Covey said.

Locally and nationally, pit bulls can do damage



Supporters and opponents of pit bull bans agree on one attribute of the animal: Pit bulls are very strong. When they do bite, the consequences can be severe.

A study published in 2011 found that pit bull attacks ended in more serious injuries and higher hospital charges. The authors used data for 82 emergency room patients attacked by dogs whose breed could be identified.

"There seems to be a distinct relationship between the severity and lethality of an attack and the breed of dog responsible," the authors wrote.

Pit bulls or pit bull mixes killed 76 people from 1979 to 1998, according to a 2000 study by the American Veterinary Medical Association. That number constituted almost one-third of the 238 dog-related fatalities that the association identified, although a more recent study raised doubts that breeds are reliably identified in data about fatal attacks.

Pit bull incidents that made headlines in Portland last year were particularly vicious for canine and human victims.

A 2-year-old girl in Springfield was taken by air ambulance to Portland for surgery after being critically injured in a September pit bull attack.

That same month, a pit bull killed a pomeranian on a Portland streetcar. Kim Shay of Southeast Portland sustained an attack in October that left her arms mangled. Eight days later, two pit bulls mauled an 8-year-old pug. Mandy Flaig of Milwaukie needed 26 stitches in November when her neighbor's rescue pit bull got loose and attacked her.

Even if a bite isn't severe enough to make news, the psychological trauma can leave lasting effects, particularly on children.

"Children can develop PTSD regardless of how severe the attack is," said Judith Cohen, a child psychiatrist at the Allegheny General Hospital in Pittsburgh, Pennsylvania.

The degree of trauma depends on the child's perception, Cohen said.

And perception, as it turns out, is also key to understanding pit bulls.

It's all about perception

Almost every month since 2011 as many as 130 dogs, most of them pit bulls, have taken a walk around Portland to show residents pit bulls aren't inherently aggressive. Cheryl Huerta, one of the founders of the Portland Pit Bull Project, leads the walks as the dogs do the things dogs do.

As people stop and stare, the "bullies" sniff around, wag their tails and look for attention.

Scoffing at the idea that pit bulls are inherently more dangerous than other dogs, Huerta said the focus should be on a different species.

"It's not the pit bulls that are the problem," she said, "It's the humans."

Human perceptions of pit bulls reflect the dog type's history, but not necessarily the animal's underlying character.

Pit bulls descend from English dogs used in the bloodsport of bull-baiting, in which a dog was sent into the ring to bite and hold large animals such as bulls and bears.

After Great Britain banned bull-baiting in the 1800s, breeders trained pit bulls to fight one another.

>>Interactive map: Portland-area bite investigations since 2010<<

Although the pit bull historically was selected for its strength and prowess in the ring, researchers have established no conclusive link between an aggressive temperament and a breed's genetic composition.

One study that did assert aggressiveness was "at least partially rooted in genetics" also found breeds other than pit bulls to be more aggressive toward humans. Among them: dachshunds, Chihuahuas and Jack Russell terriers.

The authors also found enough variations within breeds to caution that it would be "inappropriate to make predictions about a given dog's propensity for aggressive behavior based solely on its breed."

People who think that pit bulls are the most threatening type of dog should consider that the list of breeds perceived as dangerous changes with the times, said Emily Patterson-Kane, an Animal Welfare Scientist at the American Veterinary Medical Association.

In the Victorian era, great Danes were the worst. Doberman pinschers and Rottweilers had the status in the 1970s and 1980s.

Such a wide array of factors are involved that "it's usually impossible to point to any one specific influence that accounts for a dog becoming aggressive," the ASPCA says in its official statement opposing bans on specific breeds.

Experts in animal behavior say important clues to aggressive behavior lie not with the breed of the dog, but with the type of owners it attracts.

Owner behavior is key

Animal behavior experts describe some important steps to take to avoid rearing a dog prone to biting.

Thoroughly acclimate your puppy to a wide variety of stimuli at 3 to 16 weeks after birth. Avoid routinely exposing the dog to frightening situations at any stage of development. Don't rely on punishment to train your dog. And don't allow the dog to routinely bark, growl, lunge or otherwise act out at strangers.

Some breeds are less likely than others to attract owners who will follow these rules, according to academic researchers and animal welfare advocates.

Based on survey responses from 758 undergraduate students, a study published in the American Academy of Forensic Sciences found that people with pit bulls, akitas, chow chows, dobermans, wolf-mixes and Rottweilers were more likely to have committed violent crimes.

Some people get pit bulls precisely because of the dog's tough image.

"The people who want it because it's a bad dog don't spend any time socializing it, so it actually becomes a bad dog," said Covey, the Washington County animal services official. "So it actually perpetuates that perception."

Patterson-Kane said pit bull owners are less likely to spay or neuter the animals, creating a surplus of pit bull puppies. About 19 percent of the dogs that entered the Multnomah County animal shelter from September 2013 to September 2014 were pit bulls, even though they comprise only 4 percent of licensed dogs in the county.

Because pit bulls are cheap, Patterson-Kane said, they tend to attract a certain kind of buyer.

"They get picked up by people who wouldn't pay for a dog," she said.

The owner of the pit bull that mauled Kim Shay in October, Reanna Erickson, said she's not that kind of person.

"He was not raised to bite at all," Erickson said of Smokey, an American pit bull terrier.

Records show the October attack was Smokey's fourth offense.

Shay was Erickson's landlord. According to the account Shay gave at the time, she and a friend opened the door to Erickson's apartment and Smokey latched onto her friend's arm. Shay said she bit the dog's ear and cheek to get it off her friend. Then Smokey turned on her. Shay tried to fight the dog off, sliding around in her own blood, until she dragged herself out of the apartment and closed the door.

The attack left Shay's tendons, nerves and bones exposed.

Erickson said Shay, the landlord, spooked Smokey and made matters worse by biting him.

"I told her, 'Absolutely never, never go into that apartment when me and my roommate are not there because my dog's not comfortable with you,'" Erickson said.

Legislating a solution

Some have claimed the best way to put a stop to dogs like Smokey is to enact legislation imposing special restrictions on pit bulls and other breeds considered dangerous.

Pit bull advocates say such efforts can have countless unintended consequences. In particular, they say: Bad dog owners will simply move on to other breeds. But Council Bluffs says its ban on pit bulls dramatically reduced the number of pit bull attacks without increasing bites by other breeds.

Regardless of the efficacy of breed-specific restrictions, efforts to implement such legislation in Oregon have met with fierce opposition.

Former Sen. Bruce Starr, a Republican, said a backlash swept the Capitol in 2009 when he proposed a ban on pit bulls. "Every phone and email address in the building was melted down," he said.

Portland-area animal services appear content to continue with a breed-blind approach, focusing exclusively on a dog's behavior.

Washington, Multnomah and Clackamas counties have ordinances allowing authorities to put restrictions on a dog's owner if it is dangerous or potentially dangerous.

A Multnomah County dog that snarled at someone while on the loose might be labeled a Level 1. The owner would have to keep the dog from running loose on public property.

A dog that bit somebody while on the loose might be classified as a Level 4. The owner could be required to build a fence or obtain liability insurance.

The concept arose in Multnomah County in 1986, following the killing of Portland area boy by a pit bull.

Michael Oswald, the county's animal services director, said the approach has reduced recidivism.

A study he conducted found that five years before the program was implemented, 25 percent of dogs investigated for biting went on to bite again within a year. The year after the program began, 7 percent of biters repeated the offense.

Oswald said it isn't helpful to make generalizations about dog breeds or types.

"Fundamentally," Oswald said, "they are individuals."

>>Interactive map: Portland-area bite investigations since 2010<<

-- Fedor Zarkhin

fzarkhin@oregonian.com

503-294-7674; @fedorzarkhin

-- Interactive map by Mark Friesen

-- Chart by Dave Cansler

The Animal Farm Foundation says there are currently 17 states with laws pre-empting breed-specific legislation on dogs. An online post by The Oregonian/OregonLive on March 16, 2014 listed an incorrect number.