Dogs are the perfect example, not because of xenophobia, but because they are such a plain example of hypocrisy that can be refuted on every point.
Of course xenophobia is nothing new to most internet veganists, their whole thing is being intolerant to the culture of billions of people around the world, so a little additional intolerance to a few Asian countries (and a few Swiss people) probably seems like no biggie.
Saying that dog meat is an example of "depravity of meat eaters" makes no sense because the "depravity of meat eaters" is demonstrable... with any meat? That's the entire point of veganism! If a vegan believes that meat eaters are depraved, they believe they are depraved whether they eat cats, dogs, cows or pigs.
You may find some xenophobic people who are vegans but what you're much more likely to find is meat eaters who think that eating dog meat in Wuhan is depraved while eating pigs in New York is totally acceptable. Who do you think is signing the "end dog meat" petitions? Western meat eaters!
I have personally never met a vegan in person or online who thought that dog meat was more depraved than pig meat. The go to argument that vegans make is that pigs and dogs are of equivalent intelligence, that you could raise a pig as you raise a dog and have the same bond. Framing the dog meat argument as xenophobic makes absolutely no sense whatsoever and requires either a wilful ignorance or... I don't know. I cannot even understand how you contorted yourself into believing this.
You apparently have never heard or seen the fairly widespread 'the only difference is your perception' line of vegan merchandise which uses dog meat it in the opposite way: it calls out the hypocrisy of all meat-but-not-dog people. Not of a select group of people eating dog meat.