North Dakota Bovine Tuberculosis Testing Requirements for Cattle and Bison Producers

North Dakota cattle and bison producers rarely see a positive bovine tuberculosis test, but the paperwork, permits, and testing rules that keep it that way apply to nearly every animal crossing the state line. Bovine tuberculosis testing requirements in North Dakota are tied directly to the state’s federally recognized disease-free status, and a single missed test or expired permit can hold up a load of cattle at the border. Whether you’re moving breeding stock, bison, or exhibition animals, knowing when a test is required, which test qualifies, and what happens if an animal reacts can save a producer time, money, and a call from the state veterinarian’s office.

This breakdown walks through North Dakota’s TB classification, who has to test, which tests are approved, and what the state does when a suspect or reactor animal turns up.

What Is Bovine Tuberculosis and Why It Is Regulated in North Dakota

Bovine tuberculosis is a chronic bacterial disease of cattle that occasionally affects other species of mammals, and it is a significant zoonosis that can spread to humans, typically by the inhalation of aerosols or the ingestion of unpasteurized milk. The disease is caused by Mycobacterium bovis, a bacterium closely related to the pathogen behind human tuberculosis. Bovine tuberculosis is a rare disease that affects mammals, including cattle, deer, goats, dogs, and humans, and Mycobacterium bovis (M. bovis) is the bacteria that causes the disease.

Infected cattle usually show no outward symptoms, which is exactly why testing matters so much. Infected cattle are typically asymptomatic, and detection usually occurs during live animal skin testing or, more commonly, at slaughter through the national slaughter surveillance program. 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.

The federal-state partnership behind this low number has been running for more than a century. In 1917, the U.S. Bureau of Animal Industry began the National Tuberculosis Eradication Program, and APHIS and State animal health agencies collaborate with U.S. livestock producers to administer the program, which has nearly eradicated tuberculosis from the nation’s livestock population since its inception in 1917. Because milk and close animal contact are the main transmission routes, owners of infected or exposed cattle and bison must be advised of the possible danger these animals present to themselves, their families, employees, and the general public, and the danger of direct contact or consuming raw milk must be thoroughly explained, with all exposed persons advised to seek medical attention.

Pro Tip: If you raise dairy cattle in North Dakota, remember that milk safety rules layer on top of TB testing requirements. Affected herds must pasteurize milk before it reaches any person or animal, so a TB investigation can affect your entire operation, not just the tested animals.

North Dakota’s TB Classification Status and Risk Zones

North Dakota holds the highest disease-free classification the federal government offers for bovine tuberculosis. North Dakota is listed among the accredited-free states under federal regulation, alongside states such as Montana, South Dakota, Minnesota, and Wyoming. That status isn’t permanent by default. Accredited-free State or zone status must be renewed annually, and to qualify for renewal, a State must submit an annual report to APHIS certifying compliance with the Uniform Methods and Rules.

Michigan is the one notable exception in the surrounding region. Michigan remains the lone state not recognized as free of tuberculosis due to infections in some deer populations in the northern part of the state. That distinction matters for anyone importing cattle or bison, since animals coming from a non-free zone face additional testing that animals from free states don’t.

North Dakota has leaned into this reciprocity system in recent years. The North Dakota Board of Animal Health officially recognized Montana, Idaho, and Wyoming among states that have earned free status, using USDA-APHIS guidelines. This recognition allows producers to buy and import beef cattle and bison from these states with reduced vaccination and testing requirements for tuberculosis and brucellosis. As State Veterinarian Dr. Ethan Andress put it, “Tuberculosis infections are rare within domestic herds across the nation, but our industries, veterinarians and slaughter facilities are constantly surveilling for any cases that may point to a herd with infected animals.”

The stakes of maintaining this status are significant. If an affected herd is detected in a State classified as accredited-free, the state must implement a management plan, and if the State does not implement such a plan within the required 6 months, the State will lose its accredited-free status and be reclassified as modified accredited advanced. That reclassification would mean every producer in the state suddenly faces heavier testing burdens on interstate sales, which is a big reason North Dakota’s brand inspection requirements and TB surveillance work hand in hand at auction markets and border crossings.

Who Must Test and Which Animals Are Covered in North Dakota

Not every animal on a North Dakota operation needs a TB test every year. Testing obligations mostly attach to movement, age, and breeding status rather than blanket annual screening. Cattle categories that typically trigger a test requirement when crossing state lines include:

• All breeding cattle, all cattle over 18 months of age, all exhibition cattle, and all bulls
• Bison 60 days of age and older, unless originating from a recognized TB-free area
• Animals from herds not currently classified as accredited
• Animals moving into or through a state or zone with a lower TB classification than North Dakota

Bison face a slightly different threshold than cattle. A negative brucellosis test is required within 30 days prior to entry on all test-eligible bison 18 months of age and older from certain designated surveillance areas, and a negative tuberculosis test is required on all bison 60 days of age and older within 30 days prior to entry from qualifying areas, though nursing calves accompanying a negative-tested dam are exempt. That nursing-calf exemption also applies more broadly. Nursing calves accompanying negative-tested dams are generally exempt from the tuberculosis testing requirement under state cattle importation rules.

For herds that want to maintain the lightest testing burden, accredited herd status is the goal. To establish or maintain accredited herd status, the herd owner must comply with all provisions of the Uniform Methods and Rules regarding accredited herds, and all cattle and bison in the herd must be free from tuberculosis. Producers hauling animals between accredited herds, sale barns, or out-of-state buyers should also review livestock trailer requirements before loading, since disease documentation and transport rules are often checked together at weigh stations and brand inspection points.

Approved TB Testing Methods in North Dakota

North Dakota follows the same federally approved testing menu used nationwide. There are three official TB tests for cattle and bison: the caudal fold test (CFT), the comparative test (CT), and the comparative cervical test (CCT), and the Interferon Gamma Assay (Bovigam) is an official test for cattle only. Only one tuberculin product is authorized for these tests: official testing must use only bovine purified protein derivative tuberculin (PPD bovis) licensed by USDA.

Test	Type	Typical Use	Read Time
Caudal Fold Test (CFT)	Presumptive screening	Initial herd or import screening	Read at approximately 72 hours
Comparative Cervical Test (CCT)	Follow-up confirmatory	Resolving CFT suspects	Read at approximately 72 hours
Gamma Interferon Assay (Bovigam)	Laboratory blood test	Cattle only, faster confirmatory result	Lab-dependent turnaround

The caudal fold test is the workhorse of routine screening. It’s performed by injecting tuberculin into the skin fold under the tail, and the injection is made in the middle of the clipped area, with a distinct bleb noted at the site when the injection is made properly. Reading the result requires more than a glance. Test observation without palpation is unacceptable, and the veterinarian must physically feel for swelling at the injection site. 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, with a positive response usually beginning within 8 to 12 hours and peaking about 72 hours after injection.

The veterinarian who gives the injection has to be the one who reads it. The veterinarian who makes the tuberculin injection must be the one who “reads” (determines) the results of that test. Timing on follow-up testing is also strict: follow-up CCT testing must be performed within 10 days of the initial caudal-fold injection in cattle and bison, or the herd owner must wait 60 days after the injection of the CFT before a follow-up CCT can be administered.

Pro Tip: Because the tuberculin test relies on an immune response, avoid scheduling it around vaccinations or deworming. The animal being tested should not concurrently be receiving other medications, vaccinations, or anthelminthic drugs, since these agents may temporarily affect the immune system and influence the result.

Interstate and Intrastate Movement Testing Requirements in North Dakota

Getting cattle or bison across the North Dakota border starts with paperwork, not just a test result. Cattle imported into the state must generally be accompanied by an official certificate of veterinary inspection, and certificates for cattle must include an importation permit number issued by the state veterinarian before entering the state. Some movements are exempt from the CVI requirement, including cattle originating directly from a producer’s premises and consigned to an approved auction market, cattle consigned to a state or federally inspected slaughtering establishment, and cattle returning after less than thirty days out of state for exhibition with the same valid certificate.

North Dakota does not give producers a grace period on lab results. The ND State Board of Animal Health does not accept “test pending” for any testing requirements, and test results must be listed on the Certificate of Veterinary Inspection. That means a load can’t cross the border while a lab still has a sample in process.

Bison movement carries its own layer of documentation. A permit is required on all bison entering the state, except those for immediate slaughter or entering on an approved electronic certificate of veterinary inspection, and a CVI is required for all bison entering the state. Individual identification by official USDA metal eartags or approved radio frequency identification tags is required for all bison, except those for immediate slaughter. Canadian bison shipments have their own carve-out: bison coming from areas in Canada designated as tuberculosis and brucellosis free no longer need to be tuberculosis and brucellosis tested.

The state veterinarian’s office also retains broad discretion to deny entry. The state veterinarian may deny a request for an importation permit number if the cattle have not met disease testing, vaccination, or identification requirements, have not met pre-entry quarantine conditions, have been exposed to a contagious or infectious disease, or may be a threat to the health of the human or animal population of the state. Anyone moving cattle across county or state lines commercially should also confirm current brand inspection requirements, since ownership documentation and disease paperwork are usually checked at the same stop.

What Happens When a Suspect or Positive Result Occurs in North Dakota

A “suspect” reading on a caudal fold test doesn’t mean an animal has tuberculosis, but it does trigger a defined response chain. If the test produces any type of response, the veterinarian must immediately notify the APHIS-VS Area Office and state animal health officials. The caudal-fold test is used as a presumptive diagnostic procedure, and animals classified as suspect must be evaluated further by the comparative cervical test, the gamma interferon test, or sent directly to slaughter under permit.

Reporting isn’t optional for the veterinarian involved, either. 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. Follow-up confirmatory testing is handled by specially trained officials only: only Federal or State regulatory veterinarians who have had specialized training may conduct the follow-up testing.

When APHIS and state officials confirm infection in a herd, the response typically follows one of two paths:

1. Test-and-removal: Reactor animals are removed from the herd while the rest of the herd is monitored and retested under a management plan.
2. Herd depopulation: The entire herd is removed to eliminate the source of infection and support a faster return to disease-free status.

When health officials find tuberculosis in a herd, it is managed by either depopulating the herd or by testing and removing reactor animals, since tuberculosis is not treated in livestock. National investigators track these outcomes closely at the federal level, and APHIS maintains ongoing summary reporting on bovine TB investigations across all states, including any that touch North Dakota herds through interstate trade.

Quarantine and Herd Depopulation Rules in North Dakota

Once a herd is confirmed affected, movement restrictions kick in immediately, and the clock starts ticking on how quickly the state must resolve the case to protect its accredited-free status. If an affected herd is detected in a state classified as accredited-free, the herd must be depopulated and an epidemiologic investigation completed within 90 days of the detection, with no evidence of further spread, in order for the state to keep its status.

That 90-day window is why depopulation is often the faster path for accredited-free states compared to test-and-removal, which can stretch on for months or years of retesting. In states or zones previously accredited free where all affected herds were depopulated, the required period of freedom from tuberculosis before herds can be considered clear again is 2 years from depopulation, compared to 3 years in other states or zones. Quarantined animals aren’t simply held in place and forgotten, either. Movement out of a quarantined premises is tightly restricted to specific channels, such as licensed feedlots or direct-to-slaughter permits, until the herd is cleared or removed entirely.

Important Note: Bovine TB quarantine and depopulation decisions in North Dakota are made jointly by the State Board of Animal Health and APHIS Veterinary Services on a case-by-case basis. Because actual affected herds are rare, producers should contact the State Veterinarian’s office directly at the first sign of a suspect test rather than relying on general guidance.

Wildlife surveillance factors into these decisions too, particularly for operations near areas with known spillover risk. Herds are usually affected in one of two ways: purchasing infected animals or being exposed to infected wildlife. This is part of why the management plan requirement for any state at risk of losing free status includes provisions for increased surveillance for tuberculosis in animals held for exhibition and wildlife, alongside eradication of tuberculosis from individual herds.

Penalties for Non-Compliance in North Dakota

Non-compliance with North Dakota’s TB testing rules carries consequences at both the individual and statewide level. At the individual level, the most immediate penalty is a denied or revoked movement permit. As noted above, the state veterinarian may deny a request for an importation permit number if the cattle have not met disease testing, vaccination, or identification requirements set forth in state law. A denied permit effectively stops a shipment at the border until the animal is tested, retested, or turned back.

Cattle that arrive without proper documentation or testing face additional restrictions rather than automatic entry. Cattle infected, or recently exposed to any contagious or infectious disease, may not be imported into the state at all. Animals already inside the state that are found to be affected or exposed face herd-level restrictions on sale, similar to how herds infected with certain reportable diseases must be quarantined, with the quarantine prohibiting sale of intact bulls and females except to licensed, monitored feedlots or for immediate slaughter under written permit, held separate and apart from unaffected stock.

The bigger, statewide penalty for widespread non-compliance is losing accredited-free status altogether. As covered earlier, if a state or zone does not implement a required management plan within 6 months of an affected herd detection, the state or zone will lose its accredited-free status and be reclassified as modified accredited advanced. That reclassification raises testing costs and paperwork burdens for every cattle and bison producer in North Dakota, not just the herd where the infection was found, which is exactly the outcome the state’s testing and movement rules are designed to prevent.

Important Note: This article summarizes publicly available USDA-APHIS and North Dakota Department of Agriculture guidance as a general reference. It is not a substitute for consulting your accredited veterinarian or the North Dakota State Board of Animal Health for a specific herd or shipment situation, since requirements can change and individual circumstances vary.

For the most current permit forms, recognized free-state lists, and species-specific import rules, North Dakota’s Animal Health Division import requirements page is updated directly by the State Board of Animal Health. Federal test protocols and the full Uniform Methods and Rules are maintained on the APHIS NVAP reference guide. Producers moving cattle regularly should bookmark both, since a permit denied over an outdated testing requirement is far more disruptive than a five-minute call to the state veterinarian’s office beforehand.