Colorado’s rabies vaccine law is set at the county level, not statewide. Under Colorado Revised Statutes 25-4-607, county and district boards of health are authorized to require rabies vaccination for dogs, cats, ferrets, and other mammals within their jurisdiction, and most Colorado counties have done exactly that. If you live in one of them, your pet needs a current rabies vaccination from a licensed veterinarian. If you don’t, the stakes still matter: an unvaccinated pet exposed to a rabid animal faces a 120-day quarantine or euthanasia, while a vaccinated pet gets 45 days of observation at home.
How the County-Based System Works
Colorado has no statewide mandate. A 2016 bill that would have created one was postponed indefinitely in the state Senate. Instead, local boards of health decide whether to require vaccination, and their orders only take effect after being published in a local newspaper of general circulation.
State law puts one limit on local authorities: no county can require vaccination more often than the National Association of State Public Health Veterinarians recommends in its Compendium of Animal Rabies Prevention and Control. A county cannot, for example, demand annual boosters when the Compendium calls for a three-year interval. The statutory enforcement and impoundment provisions in CRS 25-4-610 and 25-4-611 only apply where a local vaccination order is in effect.1Justia Law. Colorado Code Title 25 – Section 25-4-609 – Effect of Order Requiring Inoculation of Animals
Because the specifics vary, call your county health department or animal control office to confirm what applies where you live. The schedules, fines, and licensing rules below reflect what most Colorado counties enforce, along with the statewide protocols that apply regardless of local vaccination orders.
Vaccination Schedule and the Certificate You Need
Counties that require rabies vaccination generally follow the Compendium schedule. For dogs and cats, that means a first vaccination by four months of age, a booster one year later, and boosters every three years when a three-year vaccine product is used. If you take ownership of a pet older than four months that has never been vaccinated, your county will set a window for getting it done.
Ferrets are on a different timeline. Their first vaccine is given at three months of age, with annual boosters after that. Ferrets over three months old entering Colorado must have proof of current rabies vaccination through the state Department of Agriculture.2Colorado Department of Agriculture. Bringing Small Animals into Colorado
The vaccine must be given by a licensed veterinarian using a USDA-licensed product. You will receive a rabies vaccination certificate and a tag for the pet’s collar. Keep the certificate somewhere you can grab quickly. You will need it for licensing, boarding, travel, and any bite or wildlife-exposure investigation, often on short notice.
Licensing, Fines, and Impound Costs
Many Colorado counties and municipalities tie pet licensing directly to rabies vaccination status. Boulder requires a current rabies vaccination certificate issued by a licensed veterinary clinic before issuing or renewing a dog license, and photos of rabies tags are not accepted.3City of Boulder. Dog Licensing Jefferson County similarly requires a current rabies vaccine certificate at licensing.
Fines for failing to vaccinate vary widely. Denver charges $100 for a first rabies vaccination violation, $250 for a second, and $500 for a third within 12 months.4City and County of Denver. Administrative Citations Pueblo County starts at $25 for a first offense and escalates to $300 for five or more violations.5Pueblo County. Title 06 – Animal Control
An unvaccinated pet picked up at large can be impounded. Getting the animal back usually means paying boarding fees, the citation fine, and sometimes a licensing fee on the spot. The total almost always exceeds what the vaccine itself would have cost. Low-cost rabies clinics in many Colorado communities charge between $10 and $45 per shot.
What Happens If Your Pet Is Exposed to Rabies
This is where vaccination status matters most, and the gap between the two outcomes is wide.
If Your Pet Is Unvaccinated
An unvaccinated pet that has contact with a known or suspected rabid animal faces two options: euthanasia or a 120-day strict quarantine. The quarantine runs 90 days in a facility approved by the local health department, followed by 30 days of home observation, with rabies vaccinations given on days 0, 21, and 60. The owner pays all costs.6Weld County Government. CDPHE Rabies Prevention and Control Policy – Algorithm for Domestic Animals Exposed to Wildlife
Quarantine is not guaranteed. The Colorado Department of Public Health and Environment says strict facility quarantine may not be available in every circumstance, and the call is made case by case. If quarantine isn’t available, the exposed pet must be euthanized. The same is true if the animal becomes severely ill or shows rabies signs during quarantine, or if the owner can no longer maintain confinement.7Colorado Department of Public Health and Environment. Colorado Rabies FAQ
If Your Pet Is Vaccinated
A pet with current, or even overdue, rabies vaccination documentation gets a booster within 96 hours of exposure and then 45 days of observation at home. The pet can leave the property under the owner’s physical control during that period but cannot be sold, given away, or boarded without prior approval.6Weld County Government. CDPHE Rabies Prevention and Control Policy – Algorithm for Domestic Animals Exposed to Wildlife
Bats and skunks are the main sources of rabies in Colorado, and bat bites can leave almost no visible mark. Any pet found in close contact with a bat, skunk, fox, raccoon, or coyote is treated as at risk unless the wild animal tests negative. Call your veterinarian and local health department right away if that happens.7Colorado Department of Public Health and Environment. Colorado Rabies FAQ
If Your Pet Bites a Person
Any animal bite on a person in Colorado must be reported to the local health department or health officer under CRS 25-4-603.8Justia Law. Colorado Code Title 25 – Section 25-4-603 – Report of Person Bitten by Animal to Health Department or Health Officer The biting animal is then quarantined for ten days and observed for signs of rabies. If the animal shows symptoms, it may be euthanized and its brain tissue tested. The owner pays quarantine costs, and if the animal was unvaccinated, the owner may also face civil liability for the bite victim’s medical expenses.
Medical Exemptions
Colorado allows veterinarians to issue medical exemptions when the vaccine poses a significant health risk to the animal, such as a severe allergic reaction or a compromised immune system. The veterinarian completes an Exemption from Rabies Vaccination form provided by CDPHE and includes a written statement of the medical concerns. Exemptions are reviewed and renewed periodically rather than granted permanently.
One alternative that does not qualify: a rabies antibody titer. Within the United States, a titer is not recognized as proof of immunity in place of vaccination, and veterinarians do not have legal discretion to substitute a positive titer for a current vaccine. Some local authorities have accepted titers case by case for animals with documented vaccine reactions, but no Colorado statute guarantees that option.
Traveling With Your Pet
Most states require a current rabies vaccination certificate, and many require a Certificate of Veterinary Inspection issued within 30 days of travel. Check the destination state’s rules before you leave.
Federal rules for bringing a dog back into the United States tightened in August 2024. All dogs entering the country must be at least six months old, microchipped, appear healthy on arrival, and have a CDC Dog Import Form receipt.9Centers for Disease Control and Prevention. CDC Updates Dog Importation Regulation Dogs returning from countries with a high risk of dog-maintained rabies also need a Certification of U.S.-issued Rabies Vaccination form, completed by a USDA-accredited veterinarian before departure and endorsed through USDA’s electronic system. The initial rabies vaccine must have been given at least 28 days before the form is issued, and only vaccines given at 12 weeks of age or older count.10Centers for Disease Control and Prevention. Instructions for USDA-accredited Veterinarians Completing the Certification of U.S.-issued Rabies Vaccination Form
If your dog’s vaccination has lapsed, the next shot is treated as an initial vaccination, which means a 28-day wait before the federal form can be issued. That alone can derail a trip booked last minute.