Two recent items in the news caught my attention. The first was a piece on National Public Radio about the soaring demand for, cost and shortage of trained bomb-sniffing dogs to be stationed at the nation's airports.

The second item was the special tribute paid at a recent Westminster Kennel Club Dog Show to the many search and rescue dogs that participated at Ground Zero [New York City] and the Pentagon [Washington, DC] right after the terrorist attacks of September 11, 2001.

Although a long-time dog lover, I had not considered just how important dogs are to homeland security.

According to the Associated Press, despite millions of dollars spent on sophisticated bomb-detection equipment, a dog's nose is still the best equipment for finding bombs in large buildings or airplanes.

"A dog's nose is probably the most sensitive piece of equipment going. They're enormously accurate," said Brook Miller, vice president of Barringer Technologies, a company that manufactures bomb-detecting spectrometry scanners.

The best equipment on the market today can identify chemical particles as small as one-billionth or one-trillionth of a gram, which incidentally, puts the machines in the same league as a good bomb-sniffing dog.

But when it comes to finding a bomb hidden in a large area, no machine even comes close to a canine.

"A dog can go into an area and lead you to where the odor is coming from," said Mike Herstik, who trains canines for military and law enforcement use. "Two canine teams could search a 20,000-seat arena in an hour and a half," he continued, "while it might take a full day for 30 people with trace detectors to examine the same area."

Most technology companies are quick to point out that dogs need to be fed and cared for, and they tire after only a few hours of work. But this didn't stop search and rescue dogs from working 12-hour shifts sifting through the rubble that was once the World Trade Center.

Directly following the attacks, over 300 search and rescue canines were on site at Ground Zero. Some were police department K-9 officers, including members of the New York Police Department Emergency Service Unit Canine Team, and many of the dogs and their handlers, flown in from all parts of the continent, were members of the Federal Emergency Management Administration's (FEMA's) Urban Search and Rescue teams.

The dogs' task was straight forward, but gargantuan: locate bodies buried beneath mountains of debris.

Ground Zero in lower Manhattan was dangerous footing for all rescue workers, but the dogs could go where humans could not. The animals could crawl through small openings and climb over unstable piles of debris.

Furthermore, dogs have an instinctive sense of where it is safe to go. And although rescue animals are taught to navigate agility courses, no one can teach them to have the courage, desire and drive needed to work at disaster sites.

The work of the rescue dogs was so important to search efforts that teams of veterinarians were brought in to provide round the clock care for the animals at a mobile hospital and rest area. The animals were bathed often to remove ash, smoke and debris from their coats, their eyes and noses were flushed regularly, and they were administered antibiotics and pain medication.

It was reported that less than 24 hours after the twin towers were hit, notices went out over e-mail lists that leather boots worn by search and rescue dogs were being shredded by glass and sharp metal. Within the hour, more e-mails reported that an overabundance of dog boots had been rushed to the scene.

The search and rescue dogs also found more than human bodies. At one point two and a half weeks after the attacks, rescue workers received a report of a cat crying in one of the damaged buildings at the site. Responding to the call, they sent a dog into the building to investigate. Several minutes later, the animal emerged with a barely living adult Persian cat in its mouth. "Precious," as the feline was named, spent 18 days without food, and was suffering from dehydration and injuries to her eyes due to shattered glass. The cat survived and is now back with its owner.

But perhaps the most heart-wrenching dog rescue story from the terrorist attacks centered around Omar Eduardo Rivera, a blind computer technician who was working on the 71st floor of the north tower when the hijacked airliner struck the building 25 floors above him. Rivera's guide dog "Dorado" was with him.

According to Rivera, "I stood up and could hear how pieces of glass were flying around and falling. I could feel the smoke filling up my lungs and the heat was just unbearable. Not having any sight I knew I wouldn't be able to run down the stairs and through all the obstacles like other people. I was resigned to dying and decided to free Dorado to give him a chance of escape. So I undid his lead and ordered him to go."

"I hoped he would be able to quickly run down the stairs without me and get to safety. I thought he'd be so scared he'd run. Everything was in chaos."

At that point, Dorado was swept away by the fleeing crowd, and Rivera was on his own for several minutes. But then the unexpected occurred: Rivera suddenly felt Dorado nudge him.

Rivera explained, "Dorado returned to my side and over the next hour guided me down 70 flights of stairs and out into the street, amid terrorized and panicking people. It was amazing. It was then I knew for certain he loved me just as much as I loved him. He was prepared to die in the hope he might save my life."

According to Bob Sessions, a FEMA rescue worker, "If these dogs only knew what a difference they make. Certainly, there's nothing that can replace the precision of a dog's nose - and absolutely nothing that can replace a dog's heart."