Really the idea that eating dog is morally wrong while eating cows, pigs, sheep etc is socially acceptable is really just hypocritical and a reflection of people right wing social conservatism and inability to challenge tradition and assumptions of their society and inability to separate their personal individualised emotions from a internally consistent ethical framework. The only argument against eating dog that I take seriously are from vegetarian/vegans who has a somewhat coherent and internally consistent ideology where dog eating would be considered morally wrong
I get why people are emotionally against eating dog. If you personally own a pet and develop an emotional attachment to that animal to the extent that they are considered a friend or even family. The idea of someone eating such an animal would seem ghastly.
However the fact of the matter is that not everyone individual share that attachment. Hell my grandfather opinion of dogs was of stray dirty wild animals. When a family friend brought a dog over and encourage my younger cousins in hugging it. My grandfather completely lost his shit and yelled at him for getting kids to interact physically with a dirty filthy animal. The vision of dogs isn't automatically the friendly pet that western society normally think of but sometimes a pack of wild stray dogs.
Then there was this art exhibition where this Australian-Vietnamese artist created a paper mâché of a dog and had flags of many different countries in the world superimposed on it to represent international unity Now the first controversy is that it had the south Vietnamese flag side by side with the North Vietnam flag for obvious reason (traditional south Vietnamese migrants hate what the north Vietnam flag represents. If I walk around in the Vietnamese community wearing that flag, I would be high risk of getting bashed). However what was also fascinating was that the Vietnamese community leaders object in of itself to having the south Vietnam flag on a dog itself and in particular having the south Vietnam flag extending from the body to the bottom. They consider this as "desecrating" the flag of South Vietnam. Simply put dogs don't have the same affectionate reaction to the more conservative elements of the vietnames community.
You can read more about it here page 8 http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1261&context=kunapipi or watch the YouTube video here https://m.youtube.com/watch?v=Df9Lgr8aIHA (It's shit like this why I can't take any ethnic "community leaders" seriously. They represent some of the most reactionary traditionally/socially conservative right wing element of migrant groups. Majority of migrants do not participate in these groups and they are simply self-appointed "leaders" more than anything else)
Also the fact is that there is nothing intrinsic why dogs out of all the animals are exclusive from that emotional attachment/bond with humans. If someone raise a pet pig or chicken or mice or sheep. They can develop an emotional bond with that animal and treat them as a friend and family as well and that animal can reciprocate that bond as well (considering zoo keepers developed close relationship with the animals they work with). I know a person who was upset their pet chicken died. As the Karl pilkington moaning of life episode where he was amazed in seeing a "hippopotamus in a house" showed that all sorts of animals can be domesticated.
Hell certain cultures a cow is considered a "sacred animals" and they could be "offended" that we eat them (which is equally superstitious right wing nonsense as well)
The idea that dogs are especially intelligent? Well you might as well stop eating pigs who are probably smarter than dogs http://www.dailymail.co.uk/sciencetech/article-3122303/Move-Lassie-IQ-tests-reveal-pigs-outsmart-dogs-chimpanzees.html
The only reason why people eating dog is somehow ethically wrong while eating other animals is ok is because it is against the tradition and culture of Western society. As people who know me, that's not a legitimate reason in believing something to be morally wrong. The aversion to eating dog (and whale) really indicate a lack of imagination and open mindedness with food in western society (as opposed to let's eat every type of meat/animals/insects/organs/food mentality of Asian countries)
I never ate dog before. Unfortunately the two times I visit Vietnam, the first time I was a kid in primary school and my dad forbid me in eating dog as he was afraid I would go around and boast about it to people back in school. The second time I stayed with a relative who morally opposed to eating dog (probably the consequence of South vietnam is a lot more westernised than the north. South Vietnam dog eating is pretty socially unacceptable although it is possible to do it. North Vietnam there's a dog restaurant in every corner)