Your Dog's ID

Tattooing is a permanent means of identification. Your dog would be tattooed with a series of numbers (for example, some people use their Social Security number) or letters and numbers. Your contact information is registered with an organization such as the National Dog Registry, ID Pet, or the American Kennel Club (which registers tattoos of purebreds only).

Dogs are tattooed with similar tools to those used for humans, and the procedure appears to be relatively painless, though the noise may upset some dogs. The insoluble dyes in tattoo inks or pastes will not react with blood or tissues. On light-skinned animals, black ink is preferred; green ink is better for darker-skinned dogs.

The comparatively hairless inside of the earflap and inside of the hind legs or belly are the most common places to tattoo a dog. Some owners avoid ear tattoos if their dog's ears will be clipped later, and others are concerned that thieves may cut off the tattooed ear so they can sell the dog to a research facility. (Research facilities are not permitted to accept tattooed dogs.)

If you want to have your dog tattooed, consult your vet, breeder, or local humane society to find out more about the various registries and the tattoo they suggest. Each registry has pros and cons, and fees vary. In addition, animal hospitals generally maintain records of dogs they have tattooed.

If practical, keep the tattooed area shaved for maximum visibility.

• A tattoo can be hard to see or find; the individual who finds a lost pet has to be aware of tattooing and look for the tattoo.

• A canny crook can alter a tattoo.

• When you move, you must remember to update your contact information with the registry.

• Tattoos are not completely reliable as the only method of identification; they're best when combined with collars and tags and/or microchipping.