[header] How to microchip your cat [title] Avoid microchipping your cat on your own. [step] Never inject your cat with a microchip on your own. This is illegal in many states and can cause you to have legal measures taken against you. 
[substeps] There are sellers who will sell you a microchip without going through a veterinary office, but you should never implant these devices yourself. Take these to your vet to have them checked out and implanted in the right way.