LONDON - Dog owners who refuse to fit Fido with a microchip may find themselves fetching a hefty fine, the British government said Wednesday.

All dogs in England will have to be fitted with microchips by 2016, authorities said. Britain's Environment Department said that the chips would help reunite owners with lost or stolen pets, promote animal welfare and take pressure off of animal shelters.

"It's a shame that in a nation of dog lovers, thousands of dogs are roaming the streets or stuck in kennels because the owner cannot be tracked down," Environment Secretary Owen Paterson said. "Microchipping is a simple solution that gives peace of mind to owners."

Many British pet owners already have veterinarians insert chips under the skin of dogs, cats, and rabbits in a bid to keep track of their animals. The Environment Department says 60 percent of Britain's 8 million pet dogs already have microchips, which can be scanned and matched to their owners' details. But officials say that what was once an optional extra will become mandatory in three years. Owners who do not fit their dogs with chips face fines of as much as $800.

Horse owners have had to chip their animals since 2009, a spokeswoman said. The chips will remain optional for cats -- because dogs are out in public more often than their feline counterparts, a spokeswoman said.

Different parts of the United Kingdom have different rules: The chips are compulsory in Northern Ireland; Wales is considering such a move; Scotland has no such rule.