Sniffer dogs: hot on the trail with the pet detectives
Dogs are used to detect everything from drugs to landmines, but the science behind the sniffers is surprisingly thin
A sniffer dog searches for mines along the border between Syria and Jordan. Photograph: Salah Malkawi/Getty Images
As Rosslare Europort opens at 6am, Ralph is straining to get to work. His job is to locate cash, heroin, amphetamines, marijuana and other narcotics. He will put in a long shift for what seems a pittance. When he found more than €1 million worth of heroin last summer, he sat and waited for this reward: a tennis ball.
Last month, he helped uncover 4.5kg of herbal cannabis with a street value of €90,000. Ralph is an English springer spaniel, a detection dog for the Revenue. His most important traits are a desire to work and an obsession with the ball.
Dogs like this are used to detect everything from drugs to landmines, yet the science behind sniffers is surprisingly thin. The United States invested heavily in technology after the September 2001 terrorist attacks but came to realise that a ball-obsessed dog and his nose still wins.
Dogs don’t handle or eyeball objects, and so they take a good sniff, concentrating molecules in their nose. Their nose lining is rich in receptors; while we have about six million, a sheepdog boasts 200 million receptor cells. This would allow a dog to detect a teaspoon of sugar diluted in two Olympic- sized swimming pools.
Working dogs such as labradors and spaniels are favoured, but more breeds are being recruited. There isn’t much evidence to say one breed is better than another; what is certain is that a top sniffer dog is more than a good nose or the right breed.
A certain temperament
Sniffer dog trainers say it takes a certain temperament for a dog to become a star detector – and a clue to what it takes is that, often, top sniffer dogs start out as unwanted pets.
Ralph at Rosslare was one such dog. He was sent off to the Blue Cross in England. Fortunately, someone there saw potential in the unwanted spaniel and phoned Wagtail, a dog-training company.
“The dogs we need are highly motivated and very independent and fearless. They are usually what people might call naughty dogs,” says Louise Wilson, a lead trainer at Wagtail in Wales. “These dogs are relentless, and will continue to bring you the tennis ball for hours on end.”
Denny Lawlor, Ralph’s handler in Wexford, says: “It’s the drive in him. You would know it to look at him.”
When Ralph arrived he was suffering from malnutrition and his coat and skin were in incredibly poor condition. “From Ralph’s outlook and personality you wouldn’t know it,” says Helen Evans, his trainer at Wagtail. “Ralph was always an excitable, bouncy but sweet-natured dog. He excelled in his training and is still one of the quickest dogs I ever trained.”
A rare breed
Just three or four dogs in a thousand in the pet population might have what it takes. One trainer in the US tours rescue centres looking for ball or tug-toy obsessed dogs. His best detector is a Chihuahua.
Why a dog would work hard for a mere ball might seem puzzling to us, but the ball signals an event – fun and interaction with its owner. “Some dogs are highly motivated by the game that the tennis ball indicates,” says Dr Alexandra Horowitz, a behavioural scientist and author of the book Inside of a Dog . “They might like holding the ball in their mouths and to play a game with their handler.”
Dogs have also evolved to become expert people-watchers, as Horowitz writes: “Dogs are anthropologists amongst us. They are students of behaviour, watching us in a way that the science of anthropology teaches its practitioners to look at humans.”