Cambodian dog meat traders drown, strangle and stab thousands of canines a day in a shadowy but sprawling business that traumatises workers and exposes them to deadly health risks like rabies.Khieu Chan bursts into tears when describing a job that haunts him as he goes to sleep: he kills up to six dogs a day, slicing their throats."Please forgive me. "If I don't kill you, I can't feed my family," the 41-year-old tells the 10 dogs awaiting their fate in a cage.A cheap source of protein, dog meat is still eaten in several Asian countries from China and South Korea to Vietnam and non-Muslim communities in Indonesia.Animal welfare activists say consumption has declined as the region's middle class has grown - more people own pets, and there's greater stigma associated with eating dog. But the brutal trade has flown under the radar in Cambodia where new research shows a thriving business involving roving dog catchers, unlicensed slaughterhouses and many restaurants in cities selling so-called "special meat".An estimated two to three million dogs are slaughtered annually in Cambodia, according to the NGO Four Paws, which identified more than 100 dog meats restaurants in the capital Phnom Penh and about 20 in the temple town of Siem Reap."It has this massive trade," says Katherine Polak, a Thailand-based veterinarian who works with the NGO, which recently presented findings to the government.Officials were "shocked" by the magnitude, she claims. Rabies crisisMotorbike riders criss-cross northern Cambodia trading pots, pans and cookware for unwanted dogs, loading them into a heavy rectangular cage on the back seat and making deliveries to middlemen.Live specimens fetch $2 to $3 per kilo, incentivising suppliers to collect as many as possible.Researchers say the dog meat trade is a public health crisis because it carries potentially infected animals all over the country.Cambodia has one of the highest incidence rates of rabies in the world and most cases are from dog bites.The trade also undermines local canine immunisation efforts by removing and killing vaccinated dogs.Unsanitary slaughterhouses have no safety regulations as they aren't overseen by the government, and workers wear no protective gear."I got bitten by a dog but I did not get vaccinated because when I returned it was late at night," Pring That told AFP in a village in Siem Reap as he cooked dog meat stew with fermented fish paste.Instead, the 33-year-old cleaned the wound with soap and lemon.Industrial-scale slaughterhouses in developing countries put some distance between workers and animals.But the Cambodian dog trade is hands on.After receiving delivery, shirtless men poke dogs with sticks into holding cages.They are then hung, strangled with rope, clubbed over the head or drowned in a pit filled with fetid water.Just after sunrise in a village in Siem Reap, one worker pulled a dog out of a cage and hung it on the branch of a tree near drying laundry.After gasping for breath for several minutes, it stopped moving.It was then placed in boiling water to remove fur and chopped into parts."On a good day, I kill 10 dogs or 12 dogs," says former soldier Hun Hoy."I also feel pity for them, but I have to strangle them," the 59-year-old adds. 'Hear their cries'Suppliers can earn from $750 to $1,000 in a country where wages in garment factories are under $200.Productivity is crucial."It's faster to hit them," explains Dara, 30, a collector, trader and butcher."I know it's a sin," he adds. Drowning is the preferred method of slaughter a few hours away in Kampong Cham and Kandal provinces. "By putting them in the cage and drowning them in a pit, we don't have to hear their cries," said one woman.Meat and parts are sold onto restaurants, where they are a popular with day labourers as a barbecued snack or a $1.25 soup.The psychological trauma to bring cheap meat to the table is immense and those who find a better job take it.Next to his dog cage in Takeo, Khieu Chan spoke about meeting Four Paws during their investigation of the trade.In an unconventional twist, they gave him land for farming if he would close his restaurant.One recent afternoon he helped the NGO gingerly take the sickly dogs out of the cage placed under a tree.But before they were removed and sent to Phnom Penh for treatment, he knelt by the bars to say goodbye. He says: "Now you have freedom. You are spared from death."