Image: ducks
Pat Little  /  AP
A group of 6-week-old ducks waddle away from visitors on Jim Skinner's Duck and Partridge Farm last month in Mount Pleasant Mills, Pa. Experts looking for a better way to destroy future poultry flocks infected with bird flu think they may have found it in an unlikely form: foam.
updated 6/10/2007 1:33:15 PM ET 2007-06-10T17:33:15

His eyes scan 5,000 ducks quacking and pacing across a barn longer than a football field. Jim Skinner knows exactly what he most fears.

Back in November, one of his flocks caught bird flu. He had to kill 2,500 ducks to block any spread, gassing them with carbon dioxide or simply breaking necks by hand.

“It’s the most horrible experience I’ve ever been through,” he says. He also lost $90,000 in business and came “this close” — his fingers form a pincer — to going under.

And now he spies them: ducks sprawled lifeless in the dirt, nine in all. “Boy, oh boy, we got a problem!” he blurts.

But this time, as he lays the contorted bodies in a corner, it becomes clear that dehydration probably killed them. For some reason, the ducks didn’t walk up a ramp for water. Relieved, Skinner declares, “It’s not disease!”

This time, there’d be no mass killing, but the scare hints at reinforced vigilance toward bird flu today.

Quick action needed
Under industry and government rules, flocks infected with the strongest strains are put to death as quickly as possible. That’s because if the disease spreads, it imperils both farms and foods they raise. Some strains can also sicken and kill people.

An earlier cousin of today’s bird flu strains killed perhaps 40 million people around the world during the 1918-1919 pandemic of Spanish flu. The most-feared virus today, known as H5N1, has never reached U.S. shores and has killed fewer than 200 people so far, mostly in Asia.

But mutations could let it pass more easily between people, unless its avian carriers are destroyed before it reaches that stage. More than 23 million fowl have been exterminated in U.S. outbreaks since the early 1980s. Facts not fears

The industry prefers the term “depopulate,” but no euphemism softens the raw reality of putting down birds by the tens of thousands. This may be done by electrocuting, gassing or chopping under international standards.

Yet, in a virulent outbreak, even these may be too slow and spare too many.

  1. Don't miss these Health stories
    1. Splash News
      More women opting for preventive mastectomy - but should they be?

      Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

    2. Larry Page's damaged vocal cords: Treatment comes with trade-offs
    3. Report questioning salt guidelines riles heart experts
    4. CDC: 2012 was deadliest year for West Nile in US
    5. What stresses moms most? Themselves, survey says

So representatives of industry, academia and government have been looking for another way.

For three years, they’ve investigated the fastest, cheapest and, they say, most humane way to dispatch birds en masse. After debating and field-testing, they say they’ve found an answer in an unlikely place.

Death by foam
The new poultry-killing instrument of choice is foam.

These soapy air bubbles, adapted from what firefighters use to smother blazes, can smother birds within several minutes, with minimal contact between workers and infection. Supporters say this method saves precious hours and costly labor.

The problem is that some consider it less humane than gassing. Carbon dioxide at least knocks birds unconscious before it poisons them, say its advocates.

Foam simply fills their windpipes and strangles them. “You might as well drop them in a bucket of water,” fumes Dr. Mohan Raj, a British veterinarian at the University of Bristol who specializes in animal welfare during disease control.

So, what to do? The question is especially pressing in places like central Pennsylvania.

Image: Jim Skinner
Pat Little  /  AP
Poultry farmer Jim Skinner talks about the dangers of bird flu in front of one of his poultry houses in Mount Pleasant Mills, Pa.
Here, plain-living farmers, often of Amish or Mennonite stock, tend ubiquitous poultry houses as long as airplane hangars. Almost 140 farms annually raise 50 million chickens for one company alone. Single barns may teem with 40,000 fowl, an inviting target for a virus that can travel from bird to bird in their own droppings.

The people of these rolling green lands are accustomed to living close to death. Three commercial plants keep busy plucking, skinning, and carving chicken in Fredericksburg, a simple brick village lined with banners displaying its unofficial logo, a chicken. Farmers Pride, the largest local company, promotes “humane” treatment of its Bell & Evans brand chickens, but owner Scott Sechler once had to gas more than 100,000 to stop bird flu.

He recoils at the thought, though, and has visited farms elsewhere in the hope of finding better techniques. “I’m still on the search,” he says. “I haven’t seen anywhere in the world where they can put chickens to sleep without a struggle.”

A better method
The American industry realized it needed something better when the powerful H5N1 virus first began spreading across southeast Asia in early 2004, while a weaker bird flu turned up in flocks of Delaware and Maryland. More than 400,000 chickens had to be put down in those two states.

At one poultry house, Michael Scuse, Delaware’s secretary of agriculture, watched as almost two dozen workers laid out big plastic sheets, covered up birds, and opened valves on carbon dioxide tanks. It took hours to accomplish.

“The one thing that struck me is how long it took to do it, how cumbersome the process was, and the manpower needs,” Scuse recalls.

Sometimes the process slows when willing workers are hard to find, even with the use of protective suits and respirators. “Some people in the industry were saying, ‘Wait a minute. I’m not going to go in there!’ ” acknowledges Bill Satterfield, who runs the Delaware-based Delmarva Poultry Industry trade group.

What if the strain had been faster, deadlier? “Given the challenges of this disease and the numbers we might be faced with depopulating, we had to examine other methods and look at other options,” says Dr. Darrel Styles, a federal veterinarian.

Real-life test
Bud Malone, a University of Delaware poultry specialist, knew of the soapy foam that firefighters lay down to put out forest fires. He wondered if it could be poured onto a barn floor packed with chickens until it covers their heads, and if it would then quickly kill them.

Over the next two years, experts at his school and in North Carolina worked on the concept. In one commercial system inspired by these ideas, a foam generator is towed across the poultry house on a wheeled cart. Only one or two workers need to expose themselves to the virus inside the barn.

The U.S. Department of Agriculture approved foam for outbreaks in November. It got its first real-life test in April, when it dispatched 26,000 turkeys to end a flu outbreak in West Virginia. “From a human safety standpoint, the foam technology is far superior to CO2 gassing methods,” argues Malone.

Farm equipment company Kifco, in Havana, Ill., made the foamer deployed in West Virginia and says it can do a barn in an hour, start to finish.

Is foam cruel, though? The visible reaction of poultry suggests it might not be: Though some try to leap away, most appear calm as they are quietly engulfed, according to witnesses. Hormone measurements taken by University of Delaware scientists suggest the birds are no more upset by foam than gas.

“In my mind, it’s more peaceful,” says federal veterinarian Stephen Roney, who worked in the poultry industry for 20 years. But that’s partly because foam hides any struggling and convulsions from human sight.

On the other hand, a chicken presumably feels nothing once it is put to sleep by the anesthetic effect of carbon dioxide.

“That’s why I kind of like CO2,” argues A. Bruce Webster, an animal behaviorist at the University of Georgia who helped decide depopulation plans for that leading poultry state. “I just don’t see that the birds really suffer from it.”

No humane options
The American Veterinary Medical Association has accepted foam for exterminating flocks, but with a caveat. It questions whether foaming qualifies as euthanasia — a gentle death relatively free of pain and distress.

To animal-rights campaigner Karen Davis, who founded United Poultry Concerns, in Machipongo, Va., foam is like “burying them alive.”

However, to her, carbon dioxide is hardly better. Before knocking out birds, it irritates chemical receptors in the lungs and leaves the animals short of breath.

“There is no really satisfactory, humane method to depopulate a full houseful of birds,” says animal ethicist Bernard Rollin, at Colorado State University.

But as newer, more airtight houses are going up, it is becoming possible to fill them entirely with carbon dioxide. Then there’s no need to herd flapping, frightened birds into plastic sheeting, as is often done now.

Researchers are considering other options: foam laced with CO2, or spiking feed or water with anesthetics. Some defenders of animal welfare favor more experiments with inert gases like nitrogen, which don’t seem to set off breathlessness like CO2.

Whatever the shortcomings of current techniques, federal and industry officials insist they’re ready for a big outbreak. But they acknowledge they’d probably use foam and gas as needed — and some uglier methods too.

In the worst case, with people dying, the industry might be forced simply to close barns and let birds die of thirst or disease.

© 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Discuss:

Discussion comments

,

Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments