I have found a little about them:
Tattooing and Micro-chips
Tattooing is a permanent, painless procedure which allows dogs to "phone home" if lost and deters theft. It usually involves tattooing the inside of the rear leg with an ID number of some sort. Licensed laboratories are required by law to return any tattooed animals which come to them, so people who steal dogs for sale to experimental labs check for tattoos, and release dogs they have stolen allowing them to be recovered. The act of tattooing also puts the dogs under the "branded animal act" so that those caught are charged with a federal felony rather than a local misdemeanor.
Local tattoo registries do exist, but the two better known National ones are ID Pet and National Dog Registry (NDR). These two are the most widely used and recognized, have been registering dogs for over 35 years.
ID Pet has a coded number. All tattoos begin with an X, then the agent's coded letters and then the next numerical number. ID Pet charges $15 for an individual registration and $35 for a Kennel Rate (PLR #), Call 888-283-8343 for ID Pet, they have no web address, email address is :
flubaduba@aol.com changes in ownership can be sent to this address, or US postal mail address:
ID Pet,
41 Damon Ave,
Nashua, NH 03060
NDR is based on the social security number of the owner though they now have other numbers by special arrangement. NDR charges $38 for a lifetime registration for all of your pets. This registry includes the use of your social security number on all of your dogs. Single animal registration cots $15. Tattoo agents charge their own price for the tattoo application, the registry fee is in addition to that base price. Call 800-NDR-DOGS for location of lost dogs. For the authorized tattoo agent nearest you, call National Dog Registry's office, 914-679-2355. Their web address is
www.natldogregistry.com, email address is :
ndr@ulster.net. US Postal mailing address is:
National Dog Registry,
PO Box 116,
Woodstock, NY 12498
Consider tattooing to be an insurance policy. You hope you never need it, but it is priceless when your dog is missing.
Tattoo A Pet 99% Recovery Rate
www.kaleidoscopekennel.com/tattoo.html http://www.doglogic.com/pupconsd.html#33