A microchip implant is a small chip about the size of a grain of rice and contains a unique identification code. It is implanted painlessly under the skin at the back of the neck between the pets shoulders. In Ireland all dogs must be microchipped before sale by their breeder. When your pet is microchipped it is then registered to a central national database and through this vets and others in animal welfare roles can retrieve the owner details and reunite them with their lost pets. Cats are not required to be microchipped but again it is invaluable in reuniting cats with their owners as each chip is unique to that pet.