What changed in 2019
APHIS publishes Mexico’s entry rules as a one-line update on the country page: “Effective 12/16/2019: A health certificate for dogs and cats is no longer needed to enter Mexico.” That’s the rule.
You can drive your dog across the San Ysidro border. You can fly your cat into Mexico City. You don’t bring a USDA-endorsed health certificate, because the receiving authority doesn’t ask for one anymore.
Why so many blog posts still tell you to get a Mexico cert: because the rule changed quietly, and content sites that wrote their Mexico guides between 2015 and 2018 haven’t refreshed. When someone copies an old article, they copy the old rule.
What SENASICA still does at the port
The certificate requirement going away doesn’t mean Mexican authorities skip the inspection. SENASICA (Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria) does still inspect arriving pets:
- Visible-illness check. If your dog is visibly sick — discharge, lethargy, obvious skin issue — they can be held for evaluation or refused.
- Visible parasites. External parasite signs (fleas, ticks) may trigger treatment at owner expense.
- Visible distress from transit. Particularly for cargo arrivals, signs of dehydration or stress get flagged.
This isn’t certificate-checking. It’s a visual triage at the port. Take a healthy pet across the border — no paperwork required — and you’re through.
The 2024 screwworm rule for returning to the US
Here’s the part the 2019-era rule change didn’t anticipate, and where most “Mexico is easy” advice now gets readers in trouble:
ALERT — As of November 22, 2024, Mexico is considered to be affected with screwworm. All dogs (including U.S. origin dogs returning to the U.S. after traveling to Mexico) must meet APHIS requirements for screwworm freedom certification upon entry (re-entry).
— APHIS Mexico page, last modified 2025-07-30
In plain English: a US-origin dog that travels to Mexico for any length of time has to produce a USDA-endorsed screwworm-freedom certificate to come back into the US. Same for any dog being imported from Mexico to the US.
This is separate from CDC’s dog-import rules (which also apply to US re-entry — there’s an APHIS layer and a CDC layer). Pawvisa’s /return-to-us flow walks through what the CDC requires; the screwworm certificate is the APHIS half.
The takeaway: the outbound trip to Mexico got easier in 2019. The inboundUS-return trip got harder in 2024. If you’re planning a round-trip to Mexico with your dog, factor the screwworm certificate into the return-leg planning.
Driving across the border: edge cases
For the LA-to-Tijuana / LA-to-Rosarito / LA-to-Ensenada driver, two practical notes:
- No designated port-of-entry list for pet entry into Mexico. San Ysidro, Tecate, Otay Mesa — any land border crossing works.
- CBP (Customs and Border Protection) on the US side handles your re-entry. Their stance on the screwworm requirement might differ from APHIS by-the-book — but the safer plan is to have the APHIS certificate, not to find out at the border that yours was the day they decided to enforce.
Why old blogs get this wrong
If you Google “pet health certificate Mexico” right now, three of the first ten results will tell you to get a Mexico-specific cert from a USDA-accredited vet. Some will quote the pre-2019 USDA endorsement fee. Some will describe a process that no longer applies.
The honest answer for outbound: you don’t need any of that. The honest answer for inbound (since Nov 2024): you need the screwworm-freedom certificate, which is new paperwork most of those blogs also don’t mention.
The two-sentence summary worth taking with you: Going to Mexico — no cert. Coming back to the US with a dog — APHIS screwworm cert.