Letting dogs off the leash too early, before they've learned to respond to your calls, also increases that risk. Dog trainer Mark Peters says leadership training is the key to getting your dog to come back when called. "It's easier to train your dog to come back to you on a long extendable lead first," says Peters. "If it doesn't come every time with those, then it shouldn't be coming off the lead. A dog will only come back if it respects you as its leader."

The first thing we did that evening was to split up into pairs and scour our neighbourhood on foot, calling Fung Fung's name. I was with Maximo, our three-year-old son. He was tired and hungry, so we didn't get very far and I decided to take him back home for a charred, distracted dinner. My husband and our elder son, Hugo, returned exhausted not long after.

After putting the children to bed, we took turns to continue the search. The first 24 hours are crucial, as the dog is still likely to be within a short radius of where you lost him, and Janice Jensen, director of Hong Kong Animal Speak, recommends searching the area for at least a few hours.

"Call people who know the dog to help, as the dog will respond more quickly to a familiar voice. Retrace your steps and talk to everyone you meet about what he looks like, offering your phone number in case they see him."

If a search fails, report the loss immediately to the SPCA, the Agriculture, Fisheries and Conservation Department, the local police station and nearby vet clinics, advises Jensen. "The AFCD will have a record of the microchip and will often be called to pick up a stray dog. The SPCA often picks up stray dogs, too. Many people will take a dog to a vet to see if the dog is microchipped and for advice on how to return the dog to the owner."

The next step is to make a poster. Keep it concise, ensure that it's legible from a distance and include a large, recent photo of your dog, and your phone number. It's up to you whether to offer a reward, but we followed advice not to specify the amount.

Hong Kong has strict billposting rules, so be strategic about where you place them to avoid wasting paper and effort. Use Blu-Tack instead of difficult-to-remove tape, and ask permission. You would be surprised how accommodating some business owners are, and vets and pet shops all have noticeboards you can use.

Macalister recommends encouraging people to photograph the poster, so that they can carry a record with them and share it with others. One lady called from a nearby village saying she'd shared a photo of our poster via WhatsApp with all her neighbours. We received dozens of phone calls from that village as a result.

Jill Robinson, founder and CEO of Animals Asia, spotted our poster and called to remind us to make use of social media. "Using social media such as Facebook to spread the word about a missing pet can be incredibly effective," she says. "Once you've posted a photograph, you'd be surprised how quickly word spreads. It can be really helpful to have text embedded onto the image with your contact details."

If several days go by without a result, you may want to widen your search. "How far a dog will wander depends on its personality, the weather and the terrain in which the dog was lost," says Jensen. "Dogs who are not desexed, or are driven by scent, often travel farther. Shy or fearful dogs lost in a populated area will stay away from people and hide, while outgoing dogs will approach anyone who seems friendly."

Dogs will seek shelter from rain or heat and will be on the lookout for food. "Bins and shelters can be places to look, as well as places that are familiar to the dog," says Macalister. "Also, many dogs retrace their steps. If you lose your dog during a walk, make sure you cover the area where the walk first started."

Wandering the streets calling your dog's name can be emotionally and physically exhausting. My husband and I took breaks and did search shifts each night after the children fell asleep. But it helps to have a little moral support.

You'll also have to be thick-skinned. The first day we lost Fung Fung, a neighbour suggested he'd probably been abducted and eaten. Brace yourself, too, for false leads. We had plenty, including one well-meaning young man who called at one in the morning to say he'd found our dog. When we tracked him down, he showed us a photo taken on his mobile - the dog he'd spotted was twice as big, older and brown.

"Don't be disheartened," says Jensen. "Never give up hope and look as long as you emotionally can. Your dog will respond best to you if he or she is still out there." If several weeks go by, and you tire of searching, at least maintain your campaign. Check posters are still up in key locations and talk to people who are on the street during the day, like dog walkers and street sweepers.

The hardest thing about losing Fung Fung was seeing it through our children's eyes. They were deceptively cheerful at first, but their sense of loss emerged in odd ways. One night, when I was late coming home from work, my helper overheard Maximo asking his six-year-old brother where mummy was. "Maybe she's dead," was the reply. Both asked frequently after Fung Fung's well-being and it was hard to know what to say.

"It is never easy, but the best policy is to be honest with them," says Macalister. "Try to make it a learning experience and obviously never attribute blame to the children."

"It makes us sad to think our dogs are not eating their dog food and sleeping in their beds, but they can do very well surviving outside of the home for some time," adds Jensen. "Dogs are smart and people are friendly. Even if the dog is not with you, he or she is at least usually safe."

Nearly a month after we lost Fung Fung, we got another phone call about a nearby sighting. I drove over and, once again, returned empty handed. I half-heartedly asked my husband to take Mora, our other dog, with him for one last search.

I was upstairs when I heard them return. A black dog came up the stairs and lolloped around the room in front of me; it took me several seconds to realise it was Fung Fung. I had imagined that moment so many times, it seemed surreal to actually see him again. They'd found him near our old house.

Since coming home, Fung Fung has chewed up the novel I'm reading, broken a favourite toy, and peed on our new carpet. He has a brand-new collar and shiny name tag, and wrestles daily with Mora. He's been hugged, squeezed and patted almost to death. And we're keeping him on a tight leash.