I want to know if dog meat is illegal in USA.
Is its sale banned?
Is there any criminal law against it?
Is a fine of any kind imposed?
Note: I don't in any way support dog meat. I just want to know the law and culture.
There appear to be no explicit federal laws against the practice. Each state has its own laws and many would depend on the individual interpretation of the genera "Humane Treatment of Animals" statutes.
It appears that individual states do have laws against killing cats and dogs for food.
The California law also protects "any animal traditionally or commonly kept as a pet or companion,"
Few states have specific laws barring the use of pets for food. The ones that do typically ban the slaughter or sale of dog and cat meat. The state of New York expressly prohibits "any person to slaughter or butcher domesticated dog (canis familiaris) or domesticated cat (felis catus or domesticus) to create food, meat or meat products for human or animal consumption." It's not clear whether the eating itself is outlawed or only the butchery. If you managed to buy dog or cat flesh from someone else who broke the anti-slaughter law, you might be OK. The law also doesn't cover ferrets, gerbils, parakeets, or other less familiar pet species. (Although the general anti-cruelty law might protect exotics.)
California's anti-pet-eating law has a broader reach. It bars possession of the carcass, so having bought your cat steaks from someone else wouldn't be a useful alibi. The California law also protects "any animal traditionally or commonly kept as a pet or companion," rather than just Fido and Fluffy. The statute is somewhat untested, though, so no one really knows which animals are included. Pigs are not, even though they are commonly kept as pets, because they are farm animals. Horses are specifically covered by a different section of the code. There's no precedent on iguanas, goldfish, or boa constrictors.
In most of the country, the legality of pet-eating would come down to the specific language of the general animal cruelty statute and how a judge interpreted it. Some states, such as Virginia, bar the unnecessary killing of an animal, with a specific exemption for "farming activities." In those places, it's very likely that killing a cat for dinner would get you in trouble, because the killing wouldn't be necessary, and cats aren't commonly associated with farming.
On the other end of the spectrum are states like Missouri, where very few restrictions are placed on when, why, and how an owner can kill his pet. In these areas, it would be difficult to lock up a cat-eater, unless his chosen means of slaughter were particularly inhumane.
There was also a report that a Los Angeles restaurant had been granted permission to consume and sell dog meat (American Restaurant Granted Permission To Sell Dog Meat - link now dead).
However, according to fact checking site Snopes.com, this is not true: Fact Check - American Restaurant Granted Permission to Sell Dog Meat:
Claim: A restaurant in Los Angeles or New York has been granted legal permission to serve dog meat.
The House of Representatives in September 2018 passed this bill to ban slaughter or commerce in dog or cat parts for human consumption.