In most cases the chip is fine and the scanner was wrong. Microchips are passive — no battery, no moving parts, nothing to wear out. Actual chip failure is rare. Scans that miss a working chip are not.
So before you accept “no chip found,” work through these in order.
1. Was it a universal scanner?
This is the first question and most people never ask it.
Pet microchips run on three frequencies — 125 kHz, 128 kHz and 134.2 kHz. A scanner that does not read the frequency of your pet’s chip reports nothing at all. Not an error, not a warning. It says no chip found, and it looks exactly like a dead chip.
Ask directly: does this scanner read 125, 128 and 134.2? If they do not know, ask them to try a different unit before anything else.
2. Was the whole animal scanned?
Chips migrate. They are implanted between the shoulder blades and they do not always stay there — they can travel down a leg, along the side, or toward the chest.
A quick pass over the shoulders misses a migrated chip completely. A proper scan covers neck, shoulders, both sides, chest and front legs, slowly, in overlapping passes. Migration affects readability, not your pet’s health.
3. Was anything interfering?
- Metal examination table. A known source of interference — scan on a different surface.
- The collar. Take it off, tags included.
- Other electronics nearby. Move away and try again.
- Scanning too fast. The most common handling error. A few inches per second, not a sweep.
- Low battery in the scanner. Read range drops before the unit stops working.
4. Is the chip actually the problem?
If a universal scanner has covered the whole animal slowly, on a non-metal surface, with the collar off, and still returns nothing — then the chip may genuinely have failed or was never successfully implanted.
Your vet can confirm with an X-ray, which will show a chip that is present but not reading. If there is no chip, have one implanted and register it the same day.
The failure that is far more common
People say “the microchip didn’t work” about two completely different situations, and the second one is the frequent one.
The scan worked perfectly and the number led nowhere. The chip read, the number displayed, and the registry returned no owner — because the record was never completed after the implant, or never updated after a move or a new phone number.
From the shelter’s side those two outcomes feel identical. Technically they are opposites: one is a hardware problem, the other is an empty database row.
Look your pet’s number up right now and see which situation you are actually in. It takes ten seconds and it is the only way to know.
Common questions
Do microchips stop working?
Rarely. They are passive with no battery and nothing to wear out. Failed scans are far more often a scanner, frequency or technique problem.
Can a microchip be deactivated or removed?
There is no way to switch one off remotely. Physical removal requires a surgical procedure and is uncommon.
My pet was scanned and they said no chip, but I know it has one.
Ask for a universal scanner and a full-body scan, slowly, with the collar off and away from a metal table. That resolves most of these.
Should I have a second chip implanted?
Not before a proper scan and an X-ray. Two chips in one animal creates conflicting records, which is worse than one.
Related from Peeva
- Pet microchip frequencies explained
- Universal microchip scanners
- How to scan a pet’s microchip
- Look up a microchip number
Microchip resources
Find the registry by microchip prefix · Look up a microchip number · Universal microchip scanners · Register your pet’s microchip
