On the contrary, the destinction between livestock and pets is very important to this thread. Simply because other societies do not view dogs as we do doesn't make us 'right' and them 'wrong'. IF you view all animal life the same way (as say a vegetarian or vegan) and can say that is wrong to eat any animal, then I suppose you can say that those in China and other countries who eat dogs are doing something wrong. However, if you are going to try to make a distinction and say that eating dogs is wrong, but eating chicken, pigs, or deer is right or okay, then yes, it does boil down to the distinction between livestock and pets.
That said, of course I don't like that people eat dogs; however, it is a bit holier than thou for a person to say that the animals that their society eats are okay for consumption yet to say that the consumption of a different species in another society is 'wrong' unless that person is not actively participating in the consumption of any animal species. (There is probably some argument for the consumption of fish if you want to draw the line at a species fit for consumption not having a limbic system.) Saying you don't like it is one thing (opinions are different than passing moral judgement), but to say that they are 'wrong' for it is xenocentric.
Again, I don't like that they eat dogs, and of course, it's great if people want to voice their opinions. I just think that it is important to say that our Western distinction between pets and livestock is at the heart of this issue and something to consider.