The Filipinos believe it makes the dogs taste better, and the meat is softer, if they're boiled to death rather than killed first. They like the dog's hide to be peeled off after the entire animal has been boiled in it.
Yes, Pro, I'd prefer to know that the meat I was eating hadn't been tied up with its front legs pinned unnaturally and painfully back, watching its mates being thrown into a cauldron of searing water before it is thrown in, but instead killed as humanely and painlessly as is possible. If people want to eat dogs, that's what they culturally (as per the chow in China) are used to. We eat cows, which is religious anathema to Hindus, so I don't propose to witter on about the morals or ethics of eating one animal in preference to another, or even any!
A boyfriend of mine ate 'doggo adobo' (dog stew) as a guest of Filipino colleagues in Manila, when there on business. He was complimenting the cook on how tasty the stew was, when he was told it was dog. He managed to politely finish the bowl, but decline any more. He was then offered what he took to be hard-boiled eggs, and after peeling the shell, found that they were in fact boiled embryonic chicks, complete with little claws and large eyes. Not really the most successful meal out he'd ever had, but he realised he was being honoured by the hospitality and the delicacies. Sometimes, you just have to swallow...