Bovine Tuberculosis Testing Requirements in Colorado: What Cattle Producers Must Know
August 26, 2026
If you raise, sell, or transport cattle in Colorado, bovine tuberculosis testing isn’t optional paperwork you can skip when it’s convenient. State and federal rules dictate which animals need a tuberculin test, how that test must be performed, and what happens if a cow reacts positive. Understanding these rules before you load a trailer or consign cattle to a sale barn can save you from a rejected certificate of veterinary inspection or a quarantine order at the port of entry.
This breakdown walks you through Colorado’s current bovine tuberculosis (TB) testing requirements, from who must test and which animals are covered to what happens when a suspect result shows up on the chute sheet. You’ll also find the specific timelines, forms, and penalties that apply if you move cattle without meeting the state’s disease control standards. For related disease-prevention context, see this overview of common bovine diseases affecting Colorado herds.
What Is Bovine Tuberculosis and Why It Is Regulated in Colorado
Bovine tuberculosis is a chronic bacterial disease of cattle that occasionally affects other species of mammals. The bacterium behind it, Mycobacterium bovis, is the bacteria that causes the disease, and it can survive quietly in an animal for years before producing visible symptoms.
This disease is a significant zoonosis that can spread to humans, typically by the inhalation of aerosols or the ingestion of unpasteurized milk. More broadly, disease is spread by direct contact, inhalation of droplets expelled from infected lungs, and ingestion of contaminated feed or milk. That combination of human health risk and difficulty detecting infected but healthy-looking animals is exactly why Colorado and the U.S. Department of Agriculture treat TB testing as a regulatory requirement rather than a recommendation.
The good news for Colorado producers is that the disease is uncommon. Bovine tuberculosis is a rare disease that affects mammals, including cattle, deer, goats, dogs, and humans, and the prevalence of tuberculosis in cattle, bison, and captive cervids is extremely low in the United States, with an estimated prevalence of 7 per 1 million cattle screened. That low prevalence exists because of a testing and surveillance system that has been running for more than a century: in 1917, the U.S. Bureau of Animal Industry began the National Tuberculosis Eradication Program due to human and livestock concerns regarding bovine tuberculosis.
Pro Tip: Keep copies of every tuberculin test record for your herd, even negative ones. Colorado’s accredited veterinarians are required to retain these documents for years, and having your own file speeds up import paperwork the next time you sell or relocate cattle.
Colorado’s TB Classification Status and Risk Zones
Colorado’s testing requirements exist within a national classification framework that USDA’s Animal and Plant Health Inspection Service (APHIS) uses to rate every state’s TB risk. Under federal regulation, a state or zone earns zero percent prevalence status when there is no finding of tuberculosis in any cattle, bison, or goat herd in a State or zone, and states with accredited-free standing benefit directly at the border: cattle or bison that originate in an accredited-free State or zone may be moved interstate in accordance with 9 CFR part 86 without further restriction under this part.
That status isn’t permanent. To qualify for renewal of accredited-free State or zone status, a State must submit an annual report to APHIS certifying that the State or zone within the State complies with the provisions of the “Uniform Methods and Rules—Bovine Tuberculosis Eradication.” Colorado’s own regulations echo this standard, defining an accredited free state as one that maintains full compliance with the USDA’s Uniform Methods and Rules for bovine tuberculosis eradication. You can review the federal classification language directly in 9 CFR Part 77, which governs tuberculosis control nationwide.
Risk isn’t limited to domestic herds, either. Wildlife can serve as a reservoir that reintroduces the bacteria into livestock even after a state achieves accredited-free status, which is one reason Colorado wildlife officials coordinate with agricultural regulators on surveillance near known problem areas. Producers hunting or managing land near cervid populations should also stay current on Colorado hunting license requirements, since wildlife disease monitoring often overlaps with hunting season data collection.
Important Note: A state’s accredited-free classification reflects herd-level testing and slaughter surveillance data, not a guarantee that no individual animal could ever test positive. Isolated suspect results can and do occur even in low-risk states, which is why routine testing requirements still apply to specific classes of cattle.
Who Must Test and Which Animals Are Covered in Colorado
Not every animal in Colorado needs an annual TB test, but several categories of cattle are required to test under state rules before they can move, sell, or enter approved programs. The federal baseline for what counts as a full herd test is broad: a whole herd test means an official tuberculin test of all cattle and bison in a herd that are 12 months of age or older, and of all cattle and bison in the herd that are less than 12 months of age and were not born into the herd, except those cattle and bison that are less than 12 months of age and were born in and originated from an accredited herd.
Within that framework, Colorado applies testing obligations to specific groups of animals, including:
- Grade A dairy herds: In Colorado, all dairies selling milk for human consumption must undergo a milk ordinance test every three years in which the whole herd is tested for TB.
- Approved dairy herds without accredited status: The herd shall have passed a negative Tuberculosis test within the last three years, and all cattle in the herd shall be tested, including any beef cattle and calves mingling with them, down to and including those six months of age.
- Imported breeding dairy cattle: A negative tuberculosis test is required for cattle 6 months of age or older within 60 days prior to entry into Colorado, according to the Colorado Department of Agriculture’s breeding dairy cattle import guidance.
- Rodeo cattle: A negative tuberculosis test is required for all rodeo cattle that are 6 months of age or older within 12 months prior to entry into Colorado, and the tuberculosis test date and results must be recorded on the CVI.
- Breeding bulls sold through auction markets: Bulls consigned to a livestock auction market must be tested within 60 days prior to the sale if being sold for breeding purposes.
Colorado also recognizes a higher testing tier for herds seeking accredited status. An accredited herd of cattle, bison, or dairy goats has passed at least two consecutive negative caudal fold tuberculin tests at an interval of not less than ten months nor more than fourteen months, with no other evidence of bovine tuberculosis. Achieving that status exempts younger animals born into the herd from some of the individual testing otherwise required on import or sale.
Approved TB Testing Methods in Colorado
Colorado recognizes a defined set of official tests, and only accredited or regulatory veterinarians can administer or interpret them. State rule spells this out directly: an “Official Tuberculosis Test” means any test for tuberculosis conducted on cattle or bison in accordance with the Uniform Methods and Rules for Bovine Tuberculosis Eradication, and the official tuberculin tests are the caudal fold test, the comparative cervical test, the single cervical test, or any other test approved by the Colorado State Veterinarian.
The caudal fold test (CFT) is the front-line screening tool. It is the first test used to detect possible carriers of bovine tuberculosis, in which a small amount of purified protein derivative tuberculin is injected into the fold of skin at the base of the tail, and the CFT is read 72 hours later, plus or minus six hours. Physiologically, if an animal is exposed to the antigens present in bovine TB, a tuberculin injection results in a delayed hypersensitivity reaction manifested by swelling and induration at the injection site, with a positive response usually beginning within 8 to 12 hours and peaking about 72 hours after injection.
Animals that respond to the CFT aren’t automatically infected. False positives happen, sometimes because of cross-reaction with related bacteria — a concern also relevant to poultry producers managing avian tuberculosis, a related but distinct mycobacterial disease. Colorado responders move to a confirmatory test: a Comparative Cervical Tuberculin (CCT) test must be performed within 10 days, or after 60 days, of the CFT by a regulatory veterinarian, consisting of two injections given in the skin of the neck — one of bovine tuberculin extract and one of avian tuberculin extract — with the response read 72 hours later and plotted on a scattergram that classifies the animal as negative, suspect, or reactor.
The table below summarizes the tests you’re likely to encounter during a Colorado TB workup.
| Test | Type | Typical Timing | Purpose |
|---|---|---|---|
| Caudal Fold Test (CFT) | Screening (intradermal) | Read at 72 ± 6 hours | Initial detection of possible exposure |
| Comparative Cervical Test (CCT) | Confirmatory (intradermal) | Within 10 days or after 60 days of CFT | Distinguishes suspect/reactor status after a CFT response |
| Gamma Interferon (blood test) | Confirmatory (serological) | Performed on fresh blood samples | Alternative to CCT for cell-mediated immune response |
| Necropsy and PCR/Culture | Laboratory confirmation | Post-slaughter or post-mortem | Final confirmation of M. bovis infection at NVSL |
Gamma interferon testing offers an alternative confirmatory path. A blood test measuring cell-mediated immunity in cattle has been approved as a confirmatory test that may be used instead of the CCT, though animals classified as suspect must ultimately be evaluated further by the comparative cervical test, gamma interferon test, or sent directly to slaughter under permit. Every test also requires meticulous paperwork: veterinarians must complete VS Form 6-22, the Tuberculosis Test Record, and all cattle and bison tested shall be individually identified by official eartags, with that identification recorded in its entirety on the test record at the time of injection and confirmed at the time of observation.
Interstate and Intrastate Movement Testing Requirements in Colorado
Moving cattle into, out of, or within Colorado triggers its own set of documentation rules layered on top of TB testing. Health certificates, or Certificates of Veterinary Inspection, are required on all livestock except livestock consigned directly to federally inspected slaughtering establishments and livestock moving to an approved market in Colorado from a farm of origin in an adjacent state within the normal trade area for that market. Once you’re on the road, all livestock entering the State of Colorado upon a public highway shall clear through a port of entry, and a certificate of veterinary inspection and/or a permit shall accompany the shipment as stipulated.
A CVI has a short shelf life, so timing matters. A CVI shall be void thirty days after the date of its issuance, and once issued, one copy of such certificate shall accompany the animals, while the accredited veterinarian who issued the CVI must forward a copy to the State Veterinarian within seven days of issue, and the Colorado State Veterinarian’s office shall forward all CVIs to the state of destination within seven days of receipt. If you’re hauling cattle any real distance, make sure your livestock trailer meets Colorado’s transport requirements as well, since a valid CVI won’t help if the vehicle itself is out of compliance.
Brand inspection runs alongside these health documents, not instead of them. Brand inspection is mandatory on cattle, horses, mules, and donkeys, and inspection is required regardless of whether or not the animal is branded, on all classes of stock. Full detail on when and how that inspection applies is covered in this guide to brand inspection requirements in Colorado. Some import obligations can be waived depending on destination: import requirements may be waived if cattle are moving to a Colorado-approved tagging site or a Colorado-approved feedlot, an approved tagging site being a premise authorized by APHIS, state, or tribal animal health officials where livestock may be officially identified on behalf of their owner.
Common Mistake: Producers sometimes assume a CVI issued for one sale stays valid for a later shipment. Because the certificate voids after 30 days, a delayed sale or rescheduled hauling date can leave you at the port of entry with paperwork that no longer counts as current.
What Happens When a Suspect or Positive Result Occurs in Colorado
A CFT response doesn’t mean your herd is infected, but it does start a defined chain of events. A caudal fold responder becomes a Suspect Animal that will undergo additional field tests, and the Comparative Cervical Test will be completed by your USDA or CDA field veterinarian. Any response at all triggers a reporting duty: if the test produces any type of response, you must immediately notify your APHIS-VS Area Offices and State animal health officials.
Once the CCT results come back, the animal falls into one of three categories, and each carries a different outcome:
- Negative: The animal may be returned to the herd, and no further testing is necessary, though the VS 6-22 Tuberculosis Test form should still be submitted promptly to the regional USDA office.
- Reactor: If the animal is a Reactor, it is either slaughtered or necropsied, with the body inspected for TB lesions and samples collected and sent to the National Veterinary Services Laboratories for confirmatory testing.
- Suspect: If the result is a Suspect, the owner has the option of either euthanizing the animal or quarantining the herd for 60 days, after which the cow can be retested. If it is found to be suspect or a reactor on the second test, it is slaughtered or necropsied.
Reporting obligations don’t stop with the testing veterinarian. All accredited veterinarians must immediately report every suspected or diagnosed bovine TB case promptly to both the Assistant District Director and the State Animal Health Official. The Colorado Department of Agriculture’s own tuberculosis program page outlines this coordinated state-federal response in more detail.
Quarantine and Herd Depopulation Rules in Colorado
When a herd is confirmed infected rather than merely suspect, Colorado and APHIS shift from individual animal management to herd-level control. When health officials find tuberculosis in a herd, it is managed by either depopulating the herd or by testing and removing reactor animals, and there’s no middle path involving treatment, because tuberculosis is not treated in livestock.
Quarantine doesn’t stop at the fence line of the infected premises. Colorado regulation defines an adjacent herd as a group or groups of animals having potential direct contact with the affected herd, with herds separated by a single fence considered adjacent herds. That means neighboring operations can be pulled into testing and monitoring even if none of their own animals ever leave the property. Producers reassessing exposure risk after a nearby TB finding should also review Colorado’s livestock biosecurity requirements, which cover fencing, shared equipment, and other contact points regulators scrutinize during an investigation.
Release from quarantine isn’t automatic once a herd is depopulated and restocked, either. General state quarantine standards specify that animals under quarantine for noncompliance may be released only after the State Veterinarian is satisfied by inspection, testing, treatment, or through observation over time, that the animals are not a threat to Colorado’s livestock industry. Colorado also provides some financial backstop for producers facing depopulation, since an infected herd may be eligible for indemnification pending available federal or state funds, though availability depends on program budgets at the time of the event.
Penalties for Non-Compliance in Colorado
Skipping the CVI, missing a required test, or hauling cattle without proper documentation carries real consequences at the Colorado border and beyond. Animals entering Colorado without a valid CVI or permit number, or both if required, may be held in quarantine at the owner’s expense until released by an authorized official.
If imported cattle fail to meet requirements, the State Veterinarian has several enforcement options. The State Veterinarian may order that an imported animal failing to meet import requirements be returned to its state of origin, consigned directly to slaughter, or confined to a Colorado Approved Feedlot, and the person responsible for the livestock at the time of entry shall comply with that order within five working days of its issuance. Extensions aren’t handled informally: any extension to the five-day deadline may be approved in writing and only by the State Veterinarian.
Ignoring a return order escalates the situation quickly. If the owner or owner’s agent fails to comply with an order to return livestock to the livestock’s state of origin within the required timeframe, the Department may require that the livestock be immediately gathered at the owner’s expense, and the State Veterinarian may also require that livestock ordered returned to their state of origin be returned by a commercial livestock conveyance. Colorado’s broader transport rule leaves no ambiguity about diseased animals crossing the border in the first place: no animal affected with or recently exposed to any infectious or contagious disease, or which originated from a quarantined herd or area, shall be shipped or in any manner transported into the State of Colorado, except for immediate slaughter.
The financial and logistical cost of non-compliance almost always exceeds the cost of testing on schedule in the first place. Full text of Colorado’s certificate of veterinary inspection standards, including these enforcement provisions, is available through the Colorado Code of Regulations, Title 8, Agency 1201, Division 19. Because these rules are periodically updated, confirm current requirements with the Colorado Department of Agriculture or your accredited veterinarian before you finalize any sale or shipment. For additional Colorado livestock and wildlife compliance topics, browse the broader Colorado animal regulations archive.
Important Note: This article summarizes publicly available state and federal regulatory language for general informational purposes. It is not a substitute for consulting the Colorado Department of Agriculture’s State Veterinarian’s Office or an accredited veterinarian, since specific requirements can change and may vary by herd type, origin state, and current disease status.