Border Crossing Requirements for Dogs and Cats — Mexico and US (2026)

The Complete Guide to Crossing the Border With Pets

Understanding border requirements is one of the most common concerns for pet owners considering veterinary care in Tijuana. The regulations have been updated in recent years, and there is a lot of outdated or conflicting information online. This guide provides current, accurate requirements as of March 2026.

The most important thing to know: CBX Pet Care handles all border documentation for you. Our coordinators are experienced in crossing with pets and manage all paperwork, forms, and compliance. You do not need to become an expert in import regulations — that is our job.

Dogs Entering Mexico — What Is Required

Taking a dog from the United States into Mexico is straightforward. The primary requirement is:

Mexico does not require a microchip, health certificate, or import permit for dogs entering from the United States for short stays (veterinary appointments). Our coordinators carry proof of vaccination for your dog during the border crossing.

If your dog’s rabies vaccine is expired, have it updated at your San Diego veterinarian before the appointment. The rabies vaccine must be given at least 30 days before the border crossing for it to be considered valid by some enforcement officials, so plan accordingly.

Dogs Returning to the United States — What Is Required

Bringing a dog back into the United States from Mexico involves more specific requirements than entering Mexico. The current CDC regulations (updated August 2024) require:

1. Microchip (ISO 11784/11785)

Every dog entering the United States must have an ISO-compatible microchip that can be scanned by CBP (Customs and Border Protection) officers. The microchip must be an ISO 11784/11785 standard chip — this is the international standard and is the type most commonly used worldwide.

If your dog already has a microchip: Verify that it is an ISO-compatible chip. Most microchips placed by US veterinarians in recent years are ISO-compatible. Provide us with the microchip number when you book.

If your dog does not have a microchip: No problem. Our partner clinic can place an ISO-compatible microchip during your pet’s appointment. This takes seconds, is minimally invasive (similar to a vaccine injection), and ensures your dog meets the return requirement. The microchip also provides permanent identification for your pet going forward.

2. CDC Dog Import Form

The CDC Dog Import Form is an online form that must be completed before a dog enters the United States from another country. This form creates a receipt that is presented to border officials. Key facts about the CDC form:

• The form is submitted online through the CDC website
• There is a $5 fee per dog
• The form requires basic information: owner name, dog description, microchip number, vaccination status, and countries visited
• A receipt is generated that serves as your import documentation
• CBX Pet Care fills out this form for you. Our coordinators are experienced with the form and handle it as a standard part of our service.

Cats — No Requirements in Either Direction

This makes cross-border veterinary care particularly simple for cat owners. If your cat needs dental cleaning, chemotherapy, or any other treatment, there is zero paperwork involved in the border crossing.

The CDC Dog Import Form — A Detailed Guide

Even though CBX Pet Care handles this form for you, many pet owners want to understand what it involves. Here is a complete breakdown:

What the Form Asks

• Owner information (name, contact details)
• Dog information (breed, color, sex, age)
• Microchip number (ISO 11784/11785)
• Rabies vaccination status and date of last vaccine
• Country or countries the dog has been in
• Purpose of entry (returning US-resident dog)
• Port of entry

How It Is Submitted

The form is submitted online through the official CDC import system. Once submitted and the $5 fee is paid, a receipt is generated. This receipt is what border agents review when the dog enters the US. The receipt must be available (printed or on a phone) at the time of border crossing.

Why It Exists

The CDC Dog Import Form was implemented to help prevent the reintroduction of canine rabies into the United States. The US has been free of the dog-specific rabies virus variant since 2007, and these import requirements help maintain that status. For dogs returning from short veterinary appointments in Tijuana, the form is a straightforward process.

Microchip Details — What You Need to Know

ISO 11784/11785 Standard

The required microchip standard — ISO 11784/11785 — is a 15-digit chip that operates at 134.2 kHz. This is the global standard and is the most commonly used type worldwide. Most microchips placed by US veterinarians in the past decade are ISO-compatible.

Checking Your Dog’s Existing Microchip

If your dog already has a microchip, you can verify the chip number and standard by:

• Checking your dog’s vaccination records (the chip number is usually recorded)
• Having your veterinarian scan the chip at your next visit
• Checking your microchip registration account (AVID, HomeAgain, AKC, etc.)

If the chip is a 9 or 10-digit number, it may be an older, non-ISO chip. In this case, an ISO chip can be placed alongside the existing chip at the clinic during your pet’s appointment.

If Your Dog Needs a Microchip

Microchip placement is quick and simple. A veterinarian injects the chip (about the size of a grain of rice) under the skin between the shoulder blades using a hypodermic needle. It takes seconds, requires no anesthesia, and is comparable to a routine vaccination in terms of discomfort. The chip is permanent and does not need to be replaced or recharged.

What CBX Pet Care Handles for You

To summarize exactly what our coordinators take care of regarding border documentation:

• Collecting proof of rabies vaccination before the appointment
• Verifying microchip status and noting the chip number
• Completing and submitting the CDC Dog Import Form ($5 fee)
• Carrying all documentation during the border crossing
• Presenting documentation to border agents on your behalf
• Coordinating microchip placement at the clinic if your dog does not have one

All you need to provide is proof of current rabies vaccination and your dog’s microchip number (if they already have one). We handle everything else.

Common Myths and Misconceptions

Myth: You need a USDA health certificate to bring a dog back from Mexico

This is not true for dogs returning from Mexico to the US. A USDA-endorsed health certificate (APHIS 7001) is required for some other countries, but the CDC Dog Import Form has replaced this requirement for dogs entering from Mexico and most other countries.

Myth: Dogs need a rabies titer test

A rabies titer test is required for dogs entering from high-risk rabies countries. Mexico is not classified as high-risk, so no titer test is needed for dogs crossing between the US and Mexico.

Myth: There is a waiting period after microchipping

Unlike some other countries’ import requirements, there is no waiting period between microchip placement and border crossing for dogs entering the US from Mexico. A microchip placed the same day at the clinic meets the requirement.

Frequently Asked Questions About Border Requirements

What if my dog’s rabies vaccine expires next month?

The vaccine must be current (not expired) at the time of the appointment. If it expires soon, we recommend getting a booster from your San Diego veterinarian before the appointment. This also resets your vaccine validity period.

My dog has a HomeAgain microchip from years ago. Is that okay?

It depends on the chip type. Many HomeAgain chips are ISO-compatible (15-digit, 134.2 kHz). Check your registration or have your vet scan it to confirm. If it is not ISO-compatible, an ISO chip can be placed at the clinic alongside the existing chip.

Do puppies need the same requirements as adult dogs?

Yes. All dogs, regardless of age, need a microchip and CDC Dog Import Form to return to the US. Puppies should have at least their initial rabies vaccine (given at 12-16 weeks) before crossing into Mexico.

What about emotional support animals or service dogs?

The same border requirements apply regardless of the dog’s designation. Microchip and CDC Dog Import Form are required for all dogs entering the US from Mexico. There are no exemptions for service animals or emotional support animals.

Does my pet need a passport?

No. Pet passports are a European standard and are not required for travel between the US and Mexico. The CDC Dog Import Form receipt serves as the import documentation for dogs. Cats need no documentation at all.

Has CBX ever had a problem at the border with a pet?

Our coordinators are experienced border crossers who maintain all documentation in proper order. By ensuring every dog has a valid microchip, current rabies vaccine, and completed CDC Dog Import Form, we meet all requirements every time. Proper preparation prevents border issues.

Last updated: March 2026