Domestic Travel (Inside the U.S.)
- No documents required for Service Dogs, PSDs, or ESAs.
- If you are flying, follow the airline’s requirements only.
International Entry Into Colorado
Required Documentation & Gear (must bring)
- ISO-Compliant Microchip (must match all documents)
- Rabies Vaccination Certificate
- Puppy must be 12+ weeks old at the time of vaccination
- High-risk countries: Rabies Titer required
- Low-risk countries (Canada, Western Europe, etc.): Titer not required
- Veterinary Health Certificate (vet letter confirming no known diseases)
Preferred Documentation (greatly facilitates acceptance and pre-clearance)
- Physical ID Card (animal + handler)
- Recognition Gear (Service Animal vest, bandana, or harness)
- Prescription Letter (ESA, PSA, or Service Animal letter from a licensed professional)
Important Notes
- A physical ID Card, Registration Certificate, and visible Recognition Gear speed up the processing.
- No airport restrictions: You do not need to enter through a special CDC-approved airport. You can enter at any U.S. airport as long as the airline accepts the animal and you have the required documents in your possession.
- Assistance Animals follow the same import rules as pets.
Deworming / Tapeworm Treatment Rules
Colorado does not require tapeworm treatment for dog entry.
Because of the large number of outdoor recreation areas, routine deworming is recommended but not mandatory.
Restricted Breeds at Entry
Colorado has no statewide breed restrictions.
However, several cities — including Denver (until 2021), Aurora, and others — have had Pit Bull–type breed rules. Some bans were lifted, some replaced with permit systems. Always check city-level regulations.
Public Transport & Transit Rules
Service Dogs are allowed on all public transportation throughout the state, including RTD (Denver area), Bustang, and local bus networks.
ESAs and pets may be restricted or allowed only in carriers, depending on the transit agency.