Thirty years after China adopted its infamous one-child-per-family policy, some of its cities are placing the same restriction on family dogs. While Guangzhou and Chengdu have already put the measure into force in "designated control areas," Shanghai (population: 20 million) is considering a one-dog policy. Here's a concise instant guide:

Why is Shanghai considering this move?

Shanghai officials say that the city's estimated 800,000 dogs are becoming a barking, poop-generating menace, responsible for a growing number of attacks on humans. Almost 140,000 dog-inflicted wounds were reported in 2009, a significant number of which left Shanghai residents fatally infected with rabies.

How would the ban work?

Dog owners will be urged to spay or neuter their dogs. If a dog has puppies, owners would be obligated to donate the puppies to a dogless household or a government-approved adoption center before the puppies turn three months old. When dogs die, their owners would be required to send the corpses to a state-approved disposal center.

What happens if you have more than one dog?

Violators would be fined about $150. Understandably, dog owners are worried about crackdowns: In cities that have already implemented one-dog rules, authorities have allegedly swooped into neighborhoods, clubbing dogs to death in front of their owners. An old lady named Huang, quoted in China Daily, expresses a typical fear: "If you can't find any adopters and the shelters are full, where would the puppies go?"

Is there an upside for dog lovers?

Shanghai's proposed law would lower annual registration and vaccination fees from $150-300 a year to about $45, a change presumably designed to encourage more citizens to register their dogs (only about a quarter of the city's canines are currently registered). "I doubt whether the government [would] be able to discover any violations if owners keep their dogs secretly," says another resident.

Has the one-child policy worked?

Yes, to the point where — somewhat ironically — Shanghai officials started encouraging eligible couples to start having more than one child last year. Although China plans to continue with the one-child policy, it said, in September, that about 35 percent of couples will get a pass.

Sources: AFP, China Daily, CNN, AOL News, Daily Telegraph