When a lost dog is picked up by a warden or brought into a vet surgery, the first thing that happens is a scan. If a microchip beeps and the details are correct, the phone call to the owner can happen within minutes. Without one, many lost pets are never reunited with their families.
What a microchip is
A microchip is about the size of a grain of rice. It contains a unique number and has no battery; it is powered briefly by the scanner. It is not a GPS tracker and cannot show where your pet is. The number links to a database where your contact details are stored.
Does it hurt?
The chip is injected under the skin between the shoulder blades, like a vaccine with a slightly larger needle. Most pets react no more than they would to a routine injection. It can be done at the same time as neutering, under anaesthetic, if you prefer.
Is it a legal requirement?
In many places, yes. In England, Scotland and Wales, dogs must be microchipped by eight weeks old, and since June 2024 cats in England must be chipped by 20 weeks. Many other countries and regions have their own rules, and microchips are needed for international pet travel.
The thing most owners forget
A chip with an old phone number or address is almost useless. Update the database whenever you move house or change your number — and if you adopted or bought your pet, check that the chip was transferred into your name.
Ask your vet to scan your pet at its annual check-up. This confirms the chip is still readable and lets you check the number against your records.
Complications
Problems are rare. Chips occasionally move a little under the skin, and very rarely stop working. Occasionally a small swelling appears at the site and settles. The benefits far outweigh these small risks.
Microchip cat flaps and feeders
Many cat flaps and feeders read your cat’s chip, keeping neighbourhood cats out — or stopping one cat from eating another’s prescription diet. They are especially useful in multi-cat homes.
Belt and braces
A collar tag with your phone number helps whoever finds your dog contact you directly, without a scanner. In many places dogs must wear a tag in public by law. For cats, choose a quick-release safety collar.
Questions owners ask
Can a microchip track my pet?
No. A microchip only stores an ID number. For tracking, you would need a separate GPS collar device.
How do I find out which database my pet’s chip is registered on?
Many countries have a free online look-up that tells you which database holds a chip number. Your vet can also help.
Do indoor cats need microchipping?
Yes. Indoor cats do escape — through open windows, during house moves or when a door is left open — and indoor cats that get out are often confused and hide close to home.
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