Dog owners should consider flouting new laws for mandatory microchipping, according to a specialist who warns the procedure can kill puppies and small breeds. Fines of up to 500 will be issued from April 6, the deadline for all dogs over the age of eight weeks to have the chips fitted to enable wardens to scan them for the name and address of their owner. More than a million of the country's 8.5 million dogs are still not registered and around three million more owners have failed to update their details after moving house. But Richard Allport, a senior vet and owner of the Natural Medicine Centre, said the chip can cause serious health problems for young and small dogs. I think the age by which puppies must be microchipped - eight weeks - is far too young," Mr Allport wrote in specialist magazine Dogs Today. "My advice to people who don't want their dogs microchipped is to sit tight and do nothing." The procedure involves a sterile chip, the size of a grain of rice, implanted between the shoulder blades. If the new law fails to reduce numbers of strays, wardens could eventually be deployed to patrol parks carrying out random spot-checks. Last year 110,000 stray dogs were picked up off the streets, of which 47,596 went unclaimed in council kennels. So far 86 per cent of dogs have been chipped, but the Dogs Trust said a large percentage of details on databases were out of date.