In the US for further information on laws and statutes:

AnimalLaw.info – Statutes (US)

Many animal shelters in the United States will not allow a pet to be adopted unless it has a microchip implant.
Also some U.S. military bases require pets to be microchipped.

Arizona

Arizona animal statutes provides that an impounded dog or cat shall not be released to its owner from the pound unless the dog or cat receives an implantable microchip for the purpose of identification.
(http://www.animallaw.info)

Arkansas

A dog or cat owner may obtain a lifetime dog or cat license if the animal has a microchip implant. (Annual licenses do not require dogs or cats to have a microchip implant.)
(http://www.animallaw.info/statutes/stusarodeurekasprings_northlittlerock.htm#northlittlerock)

Colorado

The court shall order any owner of a dangerous dog to have the animal implanted with a microchip. (http://www.state.co.us/gov_dir/leg_dir/olls/sl2004a/sl_370.htm)

Florida

Miami-Dade County Ordinances
All cat and dogs sold in the county must be implanted with a microchip before the sale.
(http://www.animallaw.info/statutes/stusflodmiamidadecounty_sarasota.htm#sarasota)

Georgia

Savannah, Georgia
Dogs classified as dangerous or potentially dangerous are required to be implanted with a microchip.
(http://www.animallaw.info/statutes/stusgaodlincolncounty_savannah.htm)

Hawaii

Honolulu and Maui County Statutes
Dangerous dogs are required to be microchipped.
(http://www.animallaw.info/statutes/stushiodhonolulu_maui.htm)

Illinois

West’s Smith-Hurd
According to the Illinois Animal Welfare Act a shelter or animal control agency shall not adopt out a cat or dog if it has not been microchipped.
(http://www.animallaw.info/statutes/stusilstch225_605_1_22.htm)
Chicago
Animals declared to be dangerous must be implanted with a microchip.
(http://www.animallaw.info/statutes/stusilodchicago_hillside.htm#s50

Indiana

Indianapolis
Impounded dogs and cats must be microchipped prior to being returned to the owner. Crime prevention dogs are also required to be microchipped.
(http://www.animallaw.info/statutes/stusinodindianapolis_terrehaute.htm#terre)

Kansas

Each person who possesses a dangerous “regulated” animal must have the animal microchipped. The local animal control authority must be notified regarding the animal’s microchip number and microchip manufacturer.
(http://www.animallaw.info/statutes/stusksst32_1301_1312.htm)
Concordia
Owners, keepers, harborers or possessors of dangerous dogs must have the animal microchipped and provide proof to the city clerk that a microchip has been implanted in the animal.
(http://www.animallaw.info/statutes/stusksodconcordia_manhattan.htm)

Kentucky

Lexington-Fayette Ordinances
An adoption agency must microchip an animal before adoption.
(http://www.animallaw.info/statutes/stuskyodgeorgetown_lexington.htm)

Maine

According to the Maine statutes the court may order restriction on dangerous dogs, one of which includes permanent identification of the dog by tattoo, microchip or any other means directed by the court.
(http://www.animallaw.info/statutes/stusme7msra3951_53.htm)
Maine statutes direct the commissioner to establish rules for permanent identification of all wolf hybrids by using a tattoo, microchip or any other method determined by the commissioner.
(http://www.animallaw.info/statutes/stusmest3401_4162.htm)

Michigan

The owner of a wolf-dog cross must have the animal identified with an implantable microchip.
(http://www.animallaw.info/statutes/stusmi287_1001.htm)
The owner of a large carnivore (big cats and bears) shall have the animal identified with a microchip implant.
(http://www.animallaw.info/statutes/stusmi287_1101.htm)

Minnesota

Persons who possess a “regulated” animal must have the animal microchipped. The chip number and the name of the microchip manufacturer must be provided to the local animal control authority.
(http://www.animallaw.info/statutes/stusmnst346_01_347_56.htm#s347_515)

Chanhassen and Minneapolis Animal Control Ordinances
Dogs declared as being dangerous must be implanted with a microchip. The microchip number and manufacturer of the microchip must be provided to the animal control agency.
(http://www.animallaw.info/statutes/stusmnodchanhassen_minneapolis.htm)

Missouri

Kansas City
In order to register a dangerous or potentially dangerous dog, it must be implanted with a microchip.
(http://www.animallaw.info/statutes/stusmoodkansascity_springfield.htm#springfield)

Nebraska

When a dog is declared as dangerous it must be implanted with a microchip within the next thirty days. Once the procedure is done, proof of the procedure and microchip identification number shall be provided to the animal control authority.
(http://www.animallaw.info/statutes/stusnest54_617_624.htm)

Nevada

Las Vegas and Reno
Dangerous animals must be microchipped.  Owners and keepers of wild animals (permit required) must have the animal implanted with a microchip.
(http://www.animallaw.info/statutes/stusnvodlasvegas_reno.htm#reno)

South Dakota

City of Sioux Falls Ordinances
An animal declared vicious must be permanently identified with an implantable microchip.
(http://www.animallaw.info/statutes/stussdodaberdeen_siouxfalls.htm#aberdeen)

New Mexico

Dangerous and potentially dangerous dogs must be chipped.
(http://www.animallaw.info/statutes/stusnmst77_1_1_19.htm)

New York

If a dog is proven to be dangerous, the judge or justice shall order the microchipping of the dog..
(http://www.animallaw.info/statutes/stusnyagri_mkts_121.htm)

Oregon

A dog that is not put to death because of killing, wounding, injuring or chasing livestock shall be implanted with an identifying microchip.
(http://www.animallaw.info/statutes/stusorst433_340_609_994.htm#s609_168)

South Dakota

City of Sioux Falls Ordinances
An animal declared vicious must be permanently identified with an implantable microchip.
(http://www.animallaw.info/statutes/stussdodaberdeen_siouxfalls.htm#aberdeen)

Utah

Salt Lake City
Dangerous or vicious dogs must be microchipped. The chip number must be registered with the division.
(http://www.animallaw.info/statutes/stusutodmoab_saltlakecity.htm#saltlakecity)
If an animal is impounded two or more times without wearing an identification tag, the owner may be required to have the animal microchipped.
(http://www.animallaw.info/statutes/stusutodmoab_saltlakecity.htm#saltlakecity)
Guard dogs must be microchipped.
(http://www.animallaw.info/statutes/stusutodmoab_saltlakecity.htm#saltlakecity)

In Canada for further information see:

Canadian Federation of Humane Societies
Canadian Food Inspection Agency

Canada

After purchasing a new dog one of the first things you should do is make sure it has proper identification, and ensure it is licensed if required by your municipality.

While microchipping is increasing in popularity among dog and cat owners and is advocated by the CFHS, Canada does not require a microchip or tattoo identification for pet dogs. For reasons why it’s important to microchip your pet see what the Ontario SPCA and Humane Society has to say.

Dogs that are being imported for breeding or commercial purposes must have a microchip implant.

In each sterile pouch we include a syringe implanter with removable needle/canula and protective cap. The microchip is enclosed within the needle and encoded with matching barcodes provided.
In every dispenser carton we provide 20 individually packed ergonomic syringe/implanter devices with needle/canula attached.
Post application the needle is unscrewed, the cap re-applied and the needle assembly unscrewed and disposed of in a sharps container separately from the implanter/syringe.

In order to reduce sharps waste we created the double plunger syringe implanter. This means the microchip is delivered in its own sterile canula (needle) pack, a sterile sealed pouch which includes a protective cap and a set of matching barcodes.
In every dispenser carton we provide 30 individually packed canula’s together with 3 re-usable ergonomic syringe/implanter devices.
Post application the needle is unscrewed, the cap re-applied and the needle assembly unscrewed and disposed of. This means that the syringe element can be re-used multiple times, reducing waste.

In every SwissPlus iD ziplok pack we provide everything you require. regardless of the microchip size (8mm or 12mm).

10 x Sterile Pouch Syringe Packs

30 x Sterile Bulk Needle/Canula Packs PLUS 3 re-usable syringe handles

Ziplok packs are shipped in outers of 20 for syringe packs and 10 for needle/cannula packs.