● Field note · Sequencing

Why the microchip must predate the rabies vaccine

By Pawvisa Field Desk · Last verified 2026-06-27

For almost every international destination, the microchip must be implanted before the rabies vaccine — not after. A rabies vaccination given before the microchip is treated as invalid, because the chip is what ties the vaccine record to the specific animal. It is one of the most common, most expensive resets we see.

Why the order matters

The microchip is the identity anchor. Border authorities require that the chip predates the rabies vaccine so that the vaccine record provably belongs to the animal in front of them. If the rabies shot came first, there is no way to prove the vaccine and the pet are the same record — so the destination rejects the rabies history.

The chip should be an ISO 11784/11785-compliant 15-digit microchip. Non-ISO chips (some older US chips) may not be readable at the destination, so bring your own scanner-readable record or have a compliant chip implanted.

What happens if you got it wrong

A rabies shot given before the microchip simply doesn’t count — but it doesn’t poison a later one. What matters is having a valid rabies vaccination administered AFTER the microchip, with no lapse since. So if your pet was vaccinated before being chipped but then re-vaccinated after the chip and kept current, that post-chip vaccination is the one that counts — you’re likely fine.

The problem case is when the ONLY rabies vaccination predates the chip. Then you microchip (if not already), vaccinate after the chip, and start the 21-day primary-immunity wait. For FAVN destinations the titer must sit on a valid post-chip rabies record, so if you do need a fresh post-chip primary, the titer and its waiting period restart from that point.

FAQQuick answers
Common questions
My pet was chipped as a puppy — am I safe?

Almost certainly yes. If the chip was implanted at birth or as a puppy, the first rabies vaccine necessarily came after it, so the sequencing rule cannot be violated.

Does the chip need to be a specific type?

It should be an ISO 11784/11785 15-digit chip. If yours is a non-ISO chip, either have an ISO chip implanted (before the next rabies dose) or be prepared with a compatible scanner record.

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