I thought it was just some breeds of dogs like German Shepards that were not allowed. I saw a poster some where about dogs. Many Chinese are afraid of dogs, including the police. Dogs like Golden Retrievers, Collies are not guard dogs. I saw many of these dogs. I met my girl friend when I went to see her Collie.

It is the shoulder height of the dogs that are relevant rather than bread. I do not remember the actual number, but luckily Google does 

http://www.doctorsbeckandstone.com/index.php/pet-regulations

Not sure how square they would be in enforcing these rules, but I would probably get a bread that has a bit of wiggle room in case it grows above average for its bread. 

 Dogs in many cities aren't allowed in parks etc. No one picks up after them. I tried explaining to my GF about poop scooping. No luck, oh well only Chinese will walk in it.

 Part of it comes from a fear of rabies. Many people die from rabies every year in China. There have been posts about rabies in China.  In 2009, more than 20,000 dogs were slaughtered in ten weeks in the northwest town of Hanzhong in an "irrational" reaction after eight humans were infected with rabies.

 Pet ownership in China was once rare because the Communist Party condemned it as bourgeois and most people could not afford to own cats or dogs. Now it is booming, especially in the bigger cities. Pets are seen by some as status symbols. Pedigree animals can bring big bucks. I found a Polish Maine Coon cat breeder in Gz and talked her about helping me import my MC cats. In the end I decided it was too much of a trip for them. I have shipped cats to other countries. Thats where you can make money if you aren't running a puppy/kitten mill. I never did it for money, I lost $$$, just fun. But breeding cats go for 12,000 Y or more. The markets are there for dogs and cats.