LOS ANGELES — It’s an easy law to break, and dog cheats do. By strapping a vest or backpack that says “service animal” to their pet, anyone can go in stores and restaurants where other dogs are banned, creating growing problems for the disabled community and business owners and leading to calls for better identifying the real deal.

Those with disabilities are worried about privacy and the safety of their highly trained service dogs, while business owners are concerned about health violations and damage to merchandise from impostors abusing the system.

Under the Americans with Disabilities Act, it’s a federal crime to use a fake dog. And about a fourth of all states have laws against service animal misrepresentation. But privacy protections built into the laws make it nearly impossible to prosecute offenders. It’s even more difficult because no papers are legally required for real service dogs.

Often, people who want to take their pets into restaurants or retail stores just go online to buy vests, backpacks or ID cards with a “service animal” insignia.

The law says those entering businesses with animals can be asked just two questions: Is this a service dog? What is it trained to do for you?

Efforts to make the law more prosecutable have begun, but few agree on what will work best. Ideas range from ditching privacy to doing nothing.

Corey Hudson, chief executive officer of Canine Companions for Independence in San Rafael and president of Assistance Dogs International, a coalition of training schools, is leading the effort to get the U.S. Department of Justice involved. He started writing to the agency 18 months ago but has not received a response.

There needs to be a standard, said Jennifer Arnold, founder of Canine Assistants in Atlanta.

An ID card might be the simplest answer, she said, adding that she doesn’t think the loss of privacy will be the big issue that some think it will be.

Real service dogs can be the victims of unruly fakes, said Wallis Brozman, 27, of Santa Rosa. She has dystonia, a movement disorder that left her unable to walk and barely able to talk. She needs a wheelchair, voice amplifier and her service dog, Caspin, who responds to English and sign language.

“When my dog is attacked by an aggressive dog, he is not sure what to do about it and looks to me. It becomes a safety issue, not only for my dog ... but for me if I am between the dogs.”