Last updated August 20, 2026 · Independent guide — not affiliated with USDA or SENASICA
What the rule actually says
Mexico's agricultural health authority (SENASICA) now requires every pet dog arriving from the United States to travel with the “NWS Inspection Certificate for Pet Dogs Moving (Exporting) from the United States to Mexico.” The certificate confirms a hands-on inspection found no evidence of New World screwworm, a flesh-eating parasite whose outbreak has been spreading north since 2024. Three details matter:
- Who signs it: only a USDA-accredited veterinarian. Regular licensure is not enough — accreditation is a separate federal credential, and many clinics don't have an accredited vet on staff.
- The 5-day window: the certificate must be issued within 5 days of your dog's arrival in Mexico. Count backward from the day you land or cross, not the day you book.
- No endorsement needed: the signed form goes straight in your travel folder — no APHIS endorsement step, no extra government fee.
At the Mexican port of entry, officials at the OISA (Agricultural and Livestock Health Inspection Office) will also check that your dog is free of visible disease, external parasites, and fresh or healing wounds, and that the carrier is clean. Cats are exempt from the NWS rule; pet birds need their own NWS addendum.
Your 5-step checklist
- Download the NWS Inspection Certificate form from the official USDA APHIS Mexico pet travel page.
- Find a USDA-accredited vet — call and ask by name: “Do you have a USDA-accredited veterinarian who can complete the NWS Inspection Certificate for Pet Dogs going to Mexico?”
- Book the exam for within 5 days of your arrival date in Mexico.
- Bring the printed form to the appointment; the vet inspects your dog and signs.
- Carry the signed certificate with your dog's other documents and present it at the Mexican border or airport inspection.
Find a vet who can issue the certificate
The hard part isn't the exam — it's finding a clinic that (a) has a USDA-accredited vet and (b) knows this brand-new form exists. We're building the first national directory of clinics confirmed to offer NWS certificates, city by city:
Don't see your city? Read our guide to locating an accredited vet anywhere in the US, or submit a clinic that helped you.
Traveling the other direction?
The US has its own screwworm rule for dogs arriving from Mexico. If you're making a round trip, you'll need paperwork both ways — see our Mexico-to-US screwworm certificate guide.
Frequently asked questions
What is the screwworm certificate for dogs traveling to Mexico?
It is the NWS Inspection Certificate for Pet Dogs Moving (Exporting) from the United States to Mexico — a form signed by a USDA-accredited veterinarian confirming your dog was inspected and shows no evidence of New World screwworm (NWS) infestation. It became mandatory for dogs entering Mexico from the US on August 3, 2026.
How long is the screwworm certificate valid?
The certificate must be issued and signed within 5 days of your dog's arrival in Mexico. The clock runs to the day you enter Mexico, not the day you leave the US — so book the vet appointment for the same week as your trip.
Does any vet qualify to sign the certificate?
No. Only a USDA-accredited veterinarian can issue it. Many clinics have no accredited vet on staff, and many front desks don't yet know the form by name — ask specifically whether an accredited vet can complete the NWS Inspection Certificate for Pet Dogs.
Does the certificate need USDA/APHIS endorsement?
No. Unlike many international health certificates, the NWS certificate for dogs does not require APHIS endorsement. Your accredited vet signs it and you present it directly at the Mexican border or airport.
Do cats need a screwworm certificate for Mexico?
No. Pet cats are currently exempt. Dogs need the certificate, and pet birds need a separate NWS Inspection Addendum alongside their endorsed health certificate.
How do I find out if a vet is USDA-accredited?
There is no public national lookup tool. Call the clinic and ask directly, check your state veterinary medical association's accredited-vet list where one exists, or contact your USDA APHIS state Veterinary Services office. Our city directory lists clinics that advertise accredited international certificate services.