Between 2010 and 2012, almost 20,000 abandoned and wild dogs were put down in Hong Kong, with many others left in kennels and shelters. But Millan denied that the city's pace and lack of space made it unsuitable for dogs.

"Someone who abandons their dog is likely to abandon their families as well. The difference is, the family can drive away, but the dog can't. It's left there." Owner responsibility is a strong theme in his reality TV shows and .

But owners need to be more than just responsible. Balanced dogs, Millan says, require strong 'pack leadership' from owners, in the form of exercise, discipline and affection. Most people give too much affection, and not enough exercise and discipline.

"My clients went to Harvard, but they don't know how to walk a Chihuahua. They're smart, but they don't understand nature."

He pointed to a teenage girl who was clutching her terrier protectively as it was introduced to a bulldog several times its size.

"See what she did there?" he asked, as the terrier yapped. The terrier would not naturally be afraid of the larger dog, but it had become aggressive after picking up on its owner's fear, he said. "The dog acts that way because they want to protect the human, because the human is scared."

He picked up another dog which had become alarmed by the crowd. "The best thing to do is give him a massage. Don't let him hold the experience. Change the experience."

Millan's demeanour calmed the dog instantly.

One fan, Jack Hoi, 58, a retired civil servant, admitted to having "some problems at home" with his mini-pinscher, Mickey.

Hoi said he watched Millan's YouTube show every night. "I love his philosophy on how to teach the owner," he said.