Jessica Clarke, 64, was savagely mauled April 16, 2013 by two loose pit bulls believed to have been protecting a nearby construction site.

DETROIT — The savage attack on 64-year-old Jessie Clarke outside her Detroit home on Charles last week is an extreme example of a problem that city animal control workers say is rampant.

They're the equivalent of "junkyard dogs," animals not owned as pets so much as canine security guards.

And they are becoming increasingly popular and dangerous in Detroit, a city that recorded 43,818 property crimes and thefts in 2011.

Animal Control workers intervene with these unpredictable canines as often as twice per day, says Detroit Animal Control Director Harry Ward.

Of the nearly 900 dog bites on average each year in Detroit — 932 in 2012 — as many as 5 percent, near 50, can be attributed to unattended guard dogs left at building sites, foreclosed and vacant homes.

It's a quick and often cheaper security system than traditional alarms.

Clarke, who suffered extensive injuries to her head, scalp and arms, although in stable condition, was still unconscious late last week after enduring a nearly 10-minute-long mauling by two loose pit bulls believed to have come from the former Cleveland Intermediate School across the street.

The dogs were protecting the job site from vandals and thieves, said her sons, Anthony Clarke, 41 and Dwayne Clarke, 31.

"She's a strong woman," said Anthony Clarke. "We appreciate any prayers.

"She has some surgeries to go through."

Dwayne Clarke called Jessica Clarke, "Detroit's mother," a woman who cooked for those in need and took care, not only of her three children, but their friends as well.

Bystanders used a heavy vehicle security device — similar to the Club — and pipe to try and beat the dogs off the woman. The attack ended when off-duty Detroit Police Officer Tyrone Gray, a 15-year veteran, opened fire on the animals. One survived and fled back into the school where contractors were renovating the property.

The other died at the scene.

The injured pit bull was recovered from the school with a third dog not involved in the attack, said Ward. A contractor at the scene admitted that one of the employees at the job site would drop dogs off overnight to protect materials but those animals were not involved in the attack on Clarke.

There are two dogs in custody of the Detroit Animal Control, but Ward wouldn't say if the owner or owners had been identified.

He said any animal involved in a biting incident is quarantined for 10 days to see if it exhibits signs of rabies. If the animal is already dead, or there's an need to expedite, the animal is euthanized and it's head sent to Lansing for "stem-testing."

Most people concentrate on the up to 20,000 strays that wander the streets of Detroit, but Ward says unattended guard dogs are a larger problem than most people realize.

Encountering the guard dogs can unravel quickly into a "very scary situation," he said.

"I don’t know any company that does that," said James B. Jenkins, the owner of Jenkins Construction, a large contractor that works throughout Detroit and beyond. "If they do that, that's once in a while; but we do it right."

Jenkins said paying human security guards is a "cost of doing business" that is accepted by most contractors.

The average cost per guard is $14 to $15 per hour, according to Jenkins, and multiple may be required at a job site depending on the size.

Jenkins points out that using dogs as security may be cheaper up front, but questions whether that will ultimately be the case in Jessica Clarke's situation where lawsuits could put the contractor or property owner out of business.

For several days after the attack, the former Detroit Public Schools building, usually busy with activity and workers according to neighbors, sat silent.

"I haven't seen them over there," Anthony Clarke said. "Now you work out any assumption you want to work out."

The school closed about 2008 and has been undergoing renovations for longer than a year, according to Dwayne Clark, another of Jessie Clarke's sons.

No one from the investment or contracting company had contacted the Clarke family to offer condolences or assistance.

"Beware of Dog," read a sign posted to the front door.

Although the dogs involved in the attack were pit bulls or pit bull-mixes, Ward said you "should be careful" trying to make this a "breed-specific" issue.

The "vast majority" of bites in the city come from pit bulls, said Ward, but that's because the "vast majority" of dogs owned in the city are pit bulls.

A well-raised pit bull is usually "fairly friendly," Ward said; they aren't regarded "as very good guard dogs."

A good guard dog wards off intruders with its bark rather than teeth, he said.

Ward says un-neutered male dogs and female dogs with pups pose the greatest threat to the public.

The best way to stop a dog attack is "before it starts." If you attempt to run, the dog's instincts will kick in, said Ward.

"Keep facing toward the dog and move calmly toward a safe place," Ward said.

He doesn't recommend touching a dog that is engaged in an attack. Shooting them with a hose or a fire extinguisher is a good technique to disrupt them, and a pole or extended object may be wedged in between their jaws and the victim, but he warns that could cause them to redirect their aggression.

"Dogs that maul people are not bad dogs... they are dogs in a bad situation and no longer safe to be around," Ward said. "Dogs chase other animals and bring them down.

"That's one of the things they do, whether they are a Chihuahua or a mastiff."