Why is that racist? It is a simple fact that dog and cat meat is commonly used in some Asian countries especially southern China. Horse meat is common in Europe. “Bush meat” including chimps and monkeys are used all over the world. Even cannibalism was practiced within living memory and can still be found in some areas.
I can see it being an insult if someone is talking about a strip-mall American Chinese restaurant but it may be perfectly accurate if they are actually in China. Not everyone has the same attitudes about animals and meat sources that Americans do.
It has nothing to do with race. It is about location, legality and culturally sanctioned meat sources which are fairly arbitrary.
"Historically, human consumption of dog meat has been recorded in many parts of the world, including East and Southeast Asia, West Africa, Europe, Oceania and the Americas.[2] In the 21st century, dog meat is consumed in many parts of China,[3] Korea,[4] and Vietnam.[5]
Today, a number of cultures view the consumption of dog meat as part of their traditional and day-to-day cuisine, while others – such as Western culture – consider consumption of dog meat a taboo, although they have been consumed in times of war or other hardships.[6][7] It was estimated in 2014 that worldwide, 25 million dogs are eaten each year by humans.[8]