Bovine Tuberculosis Testing Requirements in Oregon: What Cattle and Bison Owners Must Know

Bovine tuberculosis testing requirements in Oregon catch many cattle and bison owners off guard, especially those who assume that the state’s disease-free reputation means testing is optional. It isn’t. Oregon has held a clean bill of health for this disease for decades, but the Oregon Department of Agriculture (ODA) still enforces specific testing, identification, and movement rules to keep it that way.

Whether you’re bringing dairy cattle across state lines, hauling bison to a rodeo, or simply managing a home herd, you need to know which animals require a tuberculin test, who is authorized to give it, and what happens if a test comes back suspect. This guide walks through Oregon’s classification status, testing procedures, movement rules, and the penalties that apply when producers fall out of compliance.

What Is Bovine Tuberculosis and Why It Is Regulated in Oregon

Bovine tuberculosis (TB) is a contagious, infectious, communicable disease of animals and humans caused by Mycobacterium bovis, commonly a chronic, debilitating disease but occasionally may assume an acute, rapidly progressive course. The bacterium responsible, Mycobacterium bovis, doesn’t just infect cattle. TB is a widespread zoonosis of global magnitude that affects nearly all species of vertebrates, and it spreads by direct contact, inhalation of droplets expelled from infected lungs, and ingestion of contaminated feed or milk.

Because the disease can move between livestock, wildlife, and people, Oregon treats it as a reportable condition with mandatory oversight. 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. This reporting chain, paired with routine testing, is what has kept the disease out of Oregon’s commercial herds for more than three decades.

If you raise cattle or bison, understanding these rules matters beyond regulatory compliance. A single confirmed case can trigger herd quarantine, restrict sales, and jeopardize the state’s disease-free trading status with other states. For producers who also manage other animal health obligations, reviewing Oregon’s livestock biosecurity requirements alongside TB rules gives a fuller picture of herd-level disease prevention.

Oregon’s TB Classification Status and Risk Zones

Oregon’s official bovine tuberculosis status is accredited free, a classification it has held since January 13, 1989. That status places Oregon in the top tier of USDA’s national TB eradication framework, alongside brucellosis and swine pseudorabies classifications the state also maintains. Unlike states such as Michigan, which manage designated TB zones tied to wildlife reservoirs, Oregon does not currently operate under any internal modified accredited zones — the accredited-free designation applies statewide.

USDA’s Uniform Methods and Rules program defines several tiers that states or zones can fall into, and understanding where Oregon sits explains why its testing rules are less intensive than in higher-risk states:

Classification	Herd Prevalence Threshold	What It Means for Producers
Accredited-Free	Zero percent prevalence of affected cattle and bison herds, with no findings of tuberculosis for the previous 5 years	Minimal routine testing; Oregon’s current status
Modified Accredited Advanced	Tuberculosis prevalent in less than 0.01 percent of herds for each of the most recent 2 years	Increased surveillance testing required
Modified Accredited	Tuberculosis prevalent in less than 0.1 percent of herds	Mandatory herd testing programs
Accreditation Preparatory	Tuberculosis prevalent in less than 0.5 percent of herds	Intensive testing and movement restrictions

Oregon’s ODA also uses expected background response rates to monitor testing accuracy. In Oregon, a caudal-fold response rate of 0.5 percent or greater should be expected in beef cattle, and a response rate of 1 percent or greater should be expected in dairy cattle. A rate that falls significantly outside these expectations can prompt ODA to review testing technique before assuming a herd health problem.

Key Insight: Accredited-free status must be renewed annually and can be lost. If two or more affected herds are detected in an accredited-free state or zone within a 48-month period, the state or zone will be removed from the list of accredited-free states and reclassified as modified accredited advanced. That single change would trigger far stricter testing for every Oregon producer.

Who Must Test and Which Animals Are Covered in Oregon

Testing obligations in Oregon depend on the animal’s age, breed purpose, and whether it’s moving into or within the state. The core routine testing rule applies to established dairy herds: all dairy cattle over two years of age shall be tested for tuberculosis by an official veterinarian once every six years.

Beyond that baseline dairy schedule, testing is largely triggered by import or movement rather than a fixed statewide calendar for every animal. Categories that must test include:

• Imported beef breeding cattle from states that are not USDA accredited-free and have had a confirmed TB case or epidemiological evidence within the previous 12 months
• Dairy breed cattle imported for breeding and/or dairy purposes, over 2 months of age, within the 60-day period before entering the state
• Cattle over 2 months of age entering Oregon for rodeo purposes, which require a negative tuberculosis test within 12 months prior to entering Oregon
• Bison over 2 months of age entering Oregon for rodeo, show, or exhibition purposes, which also require a negative tuberculosis test within 12 months prior to entering Oregon

Coverage isn’t limited to cattle. For TB testing in species other than cattle or bison, such as cervidae, producers must contact the Oregon State Veterinarian’s office for additional guidance, since deer and elk are managed under a separate captive cervid TB framework. Bison owners transporting animals for exhibition should also check Oregon’s livestock trailer requirements, since transport documentation and testing paperwork often need to travel together.

Approved TB Testing Methods in Oregon

Oregon relies on the same federally standardized testing sequence used across the country’s TB eradication program, starting with a screening test and escalating only if results are unclear. Diagnosing TB in live animals depends on using an effective testing technique with an intradermal injection of tuberculin obtained through the USDA, and only bovine purified protein derivative tuberculin (PPD bovis) licensed by USDA is used for official testing.

Test	Purpose	Who Performs It
Caudal Fold Test (CFT)	Initial screening; intradermal tuberculin injection	Accredited veterinarians, who are legally responsible for properly conducting and evaluating results and must perform the test themselves rather than delegate it
Comparative Cervical Test (CCT)	Follow-up on suspect CFT results	Only federal or state regulatory veterinarians with specialized training
Gamma Interferon Test	Additional confirmatory diagnostic	State or federal laboratory personnel

Reading the test correctly matters as much as administering it. A veterinarian enters “N” for negative when no change appears at the injection site, and “S” for suspect when any increase in caudal fold thickness, size, or sensitivity is observed or palpated. A positive response usually begins within 8 to 12 hours and peaks about 72 hours after injection, which is why the recheck appointment timing matters for accuracy.

All results get documented on the same standardized paperwork regardless of which test is used. Veterinarians record all results on VS Form 6-22 or the Oregon Electronic Tuberculosis testing form, and every animal tested must 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.

Pro Tip: Give ODA a courtesy notification when planning TB testing. This allows the department to plan for possible CFT responders and subsequent CCT testing, which avoids unnecessary delays for you and your veterinarian.

Interstate and Intrastate Movement Testing Requirements in Oregon

Moving cattle or bison into Oregon almost always requires paperwork beyond a health certificate. A Certificate of Veterinary Inspection (CVI) issued by an accredited veterinarian is required for all beef cattle, must carry a unique serial number issued within 30 days prior to entry, and an import permit issued by ODA is also required within 30 days prior to entry. Dairy cattle face a similar structure, with the added TB testing window described above.

For cattle or bison already certified TB-free at the herd level, movement can skip individual retesting. Cattle of any breed originating from herds classified USDA accredited-free of bovine tuberculosis are exempt from further testing, provided the accredited herd number and date of latest herd test are shown on the health certificate. Producers importing from herds without that accredited status face a different track: a retest at 60 to 120 days from the date of the first test may in some cases be required, and imported cattle may be retested in the state of origin or imported into Oregon and held under quarantine subject to retest.

Rodeo and transient stock have their own carve-out. Cattle imported as transient rodeo stock must have had one negative tuberculosis test within 12 months before entry. Producers hauling animals under any of these categories should also confirm ownership documentation is in order — the brand inspection requirements in Oregon apply separately from TB testing but are frequently checked at the same points of sale or transport.

Within the state, movement is generally unrestricted for TB purposes as long as the animals came from a compliant source herd, though producers moving cattle to auction or slaughter should confirm current documentation. Cattle may move by direct delivery to a federally inspected slaughter establishment or by direct consignment to an auction market to be sold for slaughter only without the same import-level testing burden. If your operation regularly hauls livestock across county or state lines, pairing TB paperwork checks with a review of EIA Coggins test requirements in Oregon for any equine on the same trailer can prevent a mixed-species compliance gap.

What Happens When a Suspect or Positive Result Occurs in Oregon

A suspect reading doesn’t confirm infection, but it does trigger an immediate response chain. Here’s the general sequence Oregon follows once a test produces anything other than a clean negative:

1. Immediate notification — If the test produces any type of response, the testing veterinarian must immediately notify the Oregon State Veterinarian at (503) 986-4711.
2. Herd-level quarantine — In the event any suspects are detected by CFT, the entire herd must be held under quarantine until follow-up CCT testing has been conducted.
3. Specialized follow-up testing — Animals classified as suspect must be evaluated further by the comparative cervical test, gamma interferon test, or sent directly to slaughter under permit, and only federal or state regulatory veterinarians with specialized training may conduct the comparative cervical follow-up.
4. Reactor identification — Upon reading a test that reveals reactors, the veterinarian must notify the owner of the results, brand and tag any reactors with a reactor eartag, and quarantine the herd if reactors are found or individual animals if only suspect.
5. Source herd tracing — If a tuberculosis-infected bovine animal is found on post-mortem inspection at slaughter, the source herd is identified and tested by assistant state veterinarians or USDA veterinary medical officers under the applicable Uniform Methods and Rules procedures.

Because false positives do occur with the initial screening test, producers shouldn’t panic at a suspect reading. Cross-reactions from related organisms are a known limitation of caudal fold testing, which is exactly why the confirmatory CCT and gamma interferon steps exist before any destruction order is considered.

Quarantine and Herd Depopulation Rules in Oregon

When a reactor is confirmed, ODA’s authority extends well beyond isolating the animal. The State Department of Agriculture may order and compel the destruction or treatment of any livestock that may be infected with, exposed to, or may be a carrier of a disease, along with destruction of contaminated feed, bedding, and equipment that cannot be adequately disinfected.

Depopulation carries financial consequences that ODA partially offsets through indemnity. If the owner of livestock destroyed at the order of the department is eligible for indemnity payable by the federal government, the owner may also be indemnified by the State of Oregon, though the state only pays the difference between its statutory maximum and the amount payable by the federal government.

Important Note: Depopulation timing directly affects Oregon’s accredited-free status. If an affected herd is detected in an accredited-free state and the herd is depopulated with an epidemiologic investigation completed within 90 days of detection, with no evidence of spread, the state may retain its accredited-free status. Delays beyond that window put the entire state’s classification — and every producer’s testing burden — at risk.

Restocking a depopulated premises isn’t unrestricted either. If any livestock other than captive cervids are included in a newly assembled herd on a premises where a tuberculous herd has been depopulated, the state must apply the herd test requirements contained in the Uniform Methods and Rules to those animals. ODA also retains broader summary quarantine authority for any livestock suspected of exposure, independent of a confirmed depopulation order. The department may impose summary quarantine on any livestock which may be infected with, exposed to, or a carrier of a disease, and may subject that livestock to any test, treatment, or other action as a condition for release from quarantine.

Penalties for Non-Compliance in Oregon

Oregon’s enforcement structure for livestock disease violations changed significantly heading into 2026. Senate Bill 832, passed in 2025, granted the Oregon Department of Agriculture civil penalty enforcement authority beginning January 1, 2026, shifting many violations away from the older criminal citation model. Rulemaking adopted a civil penalty enforcement framework allowing violations of existing animal health regulations to be handled as civil matters, shifting enforcement from the criminal court system to an administrative process without creating new substantive compliance requirements.

Violation Category	1st Violation	2nd Violation	3rd Violation
Category I (Major)	$500	$1,500	$2,500
Category II (Moderate)	$250	$750	$2,500
Category III (Minor)	$125	$375	$2,500

Violations tied directly to TB and other reportable-disease controls carry their own escalated exposure. Category 1 violations include failing to test, treat, examine, or otherwise comply with import regulations or the conditions of an import permit, and failing to comply with rules adopted under the statutes governing disease control and reporting. Notwithstanding the standard category maximums, any violation resulting in substantial harm to human or animal health, the spread of disease to non-infected premises, or costs the department must incur to address the violation may draw a civil penalty of up to $5,000 per violation. Each 24-hour period that elapses can constitute a separate and distinct violation under the same classification.

Older statutory penalties under ORS chapter 596 remain relevant for quarantine-specific violations that predate or fall outside the new civil framework. Violation of specified provisions or any lawful ODA order is a Class A violation, while violation of the chapter’s quarantine provisions is a specific fine violation punishable by a fine of not more than $5,000. Importing livestock without the required permit carries its own automatic consequence regardless of penalty category: livestock transported into Oregon without an import permit and Certificate of Veterinary Inspection, when required, shall be held in quarantine at the owner’s risk and expense until released by the department.

Important Note: Enforcement categories and penalty amounts described here reflect Oregon’s animal health rulemaking as adopted for the civil penalty framework taking effect January 1, 2026. This article is for general informational purposes and is not legal advice — producers facing a specific compliance question or enforcement action should consult ODA’s Animal Health Program or qualified legal counsel directly.

Staying ahead of these requirements is far less costly than responding to a violation after the fact. Producers who build TB testing into routine herd management — alongside rabies vaccine requirements in Oregon and other reportable-disease obligations — typically avoid the quarantine delays and civil penalties that catch unprepared operations off guard. Oregon’s accredited-free status is a genuine asset for the state’s cattle and bison industry, but it only holds as long as producers keep doing their part at the herd level.