Bovine Tuberculosis Testing Requirements in Washington: What Cattle Owners Need to Know

Bovine tuberculosis testing requirements in Washington exist because a single infected animal can trigger a statewide investigation, herd quarantine, and months of retesting. In October 2025, state veterinarians traced a Washington-tagged cow to a New Mexico dairy herd infected with the disease, showing how quickly a records gap can put a producer’s herd under a microscope.

Washington cattle owners, dairy operators, and anyone moving livestock across state lines need to understand exactly which animals require testing, which tests are approved, and what happens if a test comes back positive. This guide walks through the rules that keep Washington’s herds protected and explains where quarantine, depopulation, and civil penalties come into play.

What Is Bovine Tuberculosis and Why It Is Regulated in Washington

Bovine tuberculosis is caused by Mycobacterium bovis, a bacterium closely related to the one that causes human tuberculosis. According to USDA APHIS, bovine tuberculosis is a contagious, infectious, communicable disease of animals and humans that is commonly chronic and debilitating, and it affects nearly all species of vertebrates, spreading through direct contact, inhalation of droplets, and ingestion of contaminated feed or milk.

The disease is rare in the United States today. 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 number is the direct result of a coordinated federal-state program: APHIS and State animal health agencies collaborate with U.S. livestock producers to administer the National Tuberculosis Eradication Program, which has nearly eradicated tuberculosis from the Nation’s livestock population since its inception in 1917.

Infected cattle rarely show visible symptoms, which is part of 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. Because the disease is zoonotic, Washington’s rules exist to protect both the state’s livestock economy and public health. You can compare how the state manages this bacterial disease against a related respiratory illness in the avian tuberculosis overview, or review broader herd health concerns in the guide to common bovine diseases.

Pro Tip: Keep every Certificate of Veterinary Inspection (CVI) on file for at least two years. Incomplete or inaccurate animal records were the exact problem that triggered Washington’s 2025 tuberculosis trace-back investigation.

Washington’s TB Classification Status and Risk Zones

Washington currently holds accredited-free status under the federal tuberculosis program, the highest tier a state can achieve. Under federal regulation, an accredited-free State or zone has the authority to enforce and comply with the provisions of the Uniform Methods and Rules for Bovine Tuberculosis Eradication, has zero percent prevalence of affected cattle and bison herds, and has had no findings of tuberculosis in any cattle or bison herds in the State or zone for the previous five years. That status must be renewed every year, and accredited-free State or zone status must be renewed annually, requiring the State to submit an annual report to APHIS certifying compliance.

State officials have confirmed this status remains solid. Following the 2025 trace-back case, WSDA stated that Washington has been TB-free for decades, and there are no confirmed cases of TB in Washington cattle or wildlife, while also noting that the premises involved was placed under temporary quarantine while records were sorted out. Officials emphasized that Washington’s TB-free status remains intact, and WSDA is taking proactive steps to ensure it stays that way.

The federal classification system that determines these risk tiers uses herd-prevalence thresholds rather than geography alone. The table below shows how APHIS defines each tier under 9 CFR Part 77.

Classification Tier	Herd Prevalence Threshold	Testing Age Requirement
Accredited-Free	Zero affected herds for 5 years	Cattle or bison 24 months of age and older
Modified Accredited Advanced	Less than 0.01% of herds affected	Cattle or bison 18 months of age and older
Modified Accredited	Less than 0.1% of herds affected for the most recent year	All cattle or bison 12 months of age and older
Accreditation Preparatory	Tuberculosis prevalent in less than 0.5% of herds	All cattle and bison regardless of age

Because Washington sits in the top tier, its own testing rules for animals born and raised in-state are relatively light. The stricter requirements in Washington’s regulations target animals entering from other states or countries with lower TB status, which is covered in the next section.

Who Must Test and Which Animals Are Covered in Washington

Washington’s domestic bovine tuberculosis rules, found in WAC 16-54-085, apply differently depending on the animal’s origin, age, and intended use. Dairy cattle, including steers and spayed heifers, twelve months of age or older and originating from a tuberculosis-free state must test negative for bovine tuberculosis within sixty days before entering Washington state.

Broader categories of cattle face testing requirements tied to risk factors rather than just age. All dairy cattle and beef cattle six months of age or older must have a negative bovine tuberculosis test within sixty days before entry into Washington state and must be officially individually identified when originating from a state or country with an active epidemiological investigation within the past twenty-four months, from a state or country where tuberculosis is endemic in wildlife, or from a modified accredited advanced or lower state.

Several categories of cattle are exempt from these requirements. According to WAC 16-54-085, dairy cattle qualify for exemption if they:

• Originate from an accredited bovine tuberculosis-free herd, with the accredited herd number and last test date shown on the certificate of veterinary inspection
• Are consigned to federally inspected slaughter facilities for immediate slaughter
• Are consigned to slaughter through state and federally approved public livestock markets, or enter a category 2 restricted holding facility to be fed for slaughter

Rodeo and timed-event cattle face their own testing window. All cattle used for rodeo or timed events, except those imported directly from Mexico, must be accompanied by proof of a negative bovine tuberculosis test within twelve months before entry into Washington state, though calves under six months old that were born and have continuously resided in Washington are excluded from this requirement. Anyone hauling these animals to an event should also check livestock trailer requirements in Washington before departure, since transport documentation is checked alongside health paperwork.

Cattle imported from Mexico face the strictest standard of any category. All Mexican cattle must be accompanied by proof of two negative bovine tuberculosis tests conducted in the United States after entry from Mexico, with the second negative test a minimum of sixty days after the first and within thirty days before entry into Washington state. Once inside the state, all Mexican cattle that remain in Washington shall be tested annually for tuberculosis.

Approved TB Testing Methods in Washington

Only USDA-approved tests count toward Washington’s entry and herd-testing requirements, and only accredited veterinarians may perform them. All TB testing of cattle or bison in Washington state is performed by a veterinarian accredited by USDA’s Animal and Plant Health Inspection Service, and those veterinarians must complete specific training. All accredited veterinarians who test cattle or bison in Washington for TB are required to successfully complete training in tuberculosis testing procedures provided by USDA or WSDA, and veterinarians who do not meet this deadline may not perform official TB testing until training is completed.

The presumptive screening test used most often is the caudal fold test. 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, gamma interferon test, or sent directly to slaughter under permit. Testing relies on a specific biological reaction, so timing and animal condition both matter:

• Only bovine purified protein derivative tuberculin (PPD bovis) licensed by USDA may be used for official testing
• The animal being tested should not concurrently be receiving other medications, vaccinations, or anthelminthic drugs, since these may temporarily affect the immune system and influence the tuberculin test result
• A positive response from tuberculin injection is a delayed hypersensitivity reaction that usually begins within 8 to 12 hours and peaks about 72 hours after injection
• The gamma interferon test is not approved for use in bison or captive cervidae

Follow-up confirmatory testing has its own strict timeline. Follow-up comparative cervical 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 (90 days for cervidae) after the CFT injection before a follow-up test can be applied. All results must be documented properly, since the testing veterinarian must complete VS Form 6-22, the Tuberculosis Test Record, identifying the animal by its official identification, and all cattle and bison tested shall be individually identified by official eartags.

Pro Tip: Schedule TB testing separately from routine vaccinations. Since medications and vaccines can suppress the immune response the tuberculin test relies on, testing too close to a vaccination appointment can produce an unreliable result.

Interstate and Intrastate Movement Testing Requirements in Washington

Moving cattle into, out of, or within Washington triggers its own paperwork trail separate from the TB test itself. All beef cattle 12 months of age or older must have a negative bovine tuberculosis test within sixty days before entry into Washington state and must be officially individually identified, and all cattle require a CVI, an entry permit, and must be individually identified on the CVI.

Bulls and breeding females face additional layered testing beyond TB alone. Bulls over the age of 18 months must also have a negative trichomoniasis test result within the last 60 days on the CVI, and all female beef cattle over 4 months of age require bangs vaccination and a legible tattoo. Cattle that don’t meet requirements aren’t necessarily turned away at the border; they can be redirected. Cattle that have not met the tuberculosis requirements may enter, with approval from the director, a category 1 restricted holding facility in Washington state until testing requirements have been met, provided the facility is approved by the director and operated under a written agreement, with all inspections and testing done at the owner’s expense.

Leaving the state carries its own compliance step entirely separate from TB testing. All cattle leaving Washington State must be accompanied by a brand inspection. If you’re planning to sell or relocate cattle across state lines, review the brand inspection requirements in Washington well before the move date, since both documents typically need to be current at the same time.

Cattle passing through Washington en route to slaughter follow a more streamlined path. Cattle need to be tested no more than 60 days before entry, and cattle coming from Canada to a Category 2 Restricted Holding Facility must remain in slaughter channels once in Washington and must not be commingled with breeding cattle. Rodeo stock gets no special pass on this front: cattle going to exhibition and then returning home must meet the same requirements as cattle going to private ownership, and rodeo stock are not exempt from testing requirements.

What Happens When a Suspect or Positive Result Occurs in Washington

A response to the caudal fold test doesn’t automatically mean an animal has tuberculosis, but it does trigger a defined chain of events. If the test produces any type of response, the veterinarian must immediately notify the APHIS Veterinary Services Area Office and state animal health officials. Reporting isn’t optional or delayed:

1. 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
2. Suspect animals must be evaluated further by the comparative cervical test, the gamma interferon test, or sent directly to slaughter under permit
3. Only Federal or State regulatory veterinarians with specialized training may conduct the confirmatory follow-up testing
4. Any animal that responds to the comparative cervical test is classified as a reactor

Classification carries real consequences for the individual animal. Reactor cattle and bison must be identified by branding the letter “T” on the left hip near the tailhead, or tagged with an approved metal eartag inscribed “U.S. Reactor,” and such reactors may be shipped to slaughter under permit. There’s also a firm deadline on that movement. Reactors shall remain on the premises where they were disclosed until a state or federal permit for movement has been obtained, and movement for immediate slaughter shall be within 15 days of classification, directly to a slaughtering establishment where approved inspection is maintained.

Important Note: A “suspect” classification is not a confirmed diagnosis. Washington relies on the comparative cervical or gamma interferon test to confirm or clear a suspect result before any quarantine or reactor status is applied, consistent with USDA’s national protocol.

Quarantine and Herd Depopulation Rules in Washington

Once a reactor is confirmed in a herd, the entire herd’s status changes immediately. All herds in which reactor animals are disclosed shall be quarantined, and the rules don’t allow selective movement of the rest of the herd. The remaining exposed animals must remain on the premises where the disease was disclosed unless a state or federal permit for movement to slaughter has been obtained.

Federal guidance treats depopulation as the preferred outcome for an affected herd. Every effort shall be made to ensure the immediate elimination of the disease from all species of domestic livestock on the premises, and the first consideration in affected herds is depopulation of the entire herd; if depopulation cannot be accomplished, the herd shall be handled under quarantine procedures instead. Herds that avoid depopulation face a demanding retest schedule before release. Herds in which Mycobacterium bovis infection has been confirmed and the herd has not been depopulated will remain under quarantine and must pass two tuberculin tests at intervals of at least sixty days and one additional test after six months, and following release from quarantine these herds are also subject to five annual tests on the entire herd.

Sales out of a quarantined herd are heavily restricted, not eliminated entirely. Sale of feeder calves from quarantined herds shall be restricted, though feeder calves under 12 months of age that have passed a caudal fold test within 60 days may be permitted to move intrastate to a quarantined feedlot. Newly assembled herds on previously affected premises aren’t automatically clear either. Negative annual herd tests shall be applied to all cattle, bison, and other livestock on the premises, with the first test applied approximately 6 months after assembly of the new herd.

Nearby herds don’t escape scrutiny during an active investigation. All livestock herds within a 10-mile radius will be tested within 6 months of any diagnosis of bovine tuberculosis. Producers managing mixed livestock operations should also check rabies vaccine requirements in Washington, since a disease investigation on one species can prompt closer review of a property’s overall animal health compliance.

Penalties for Non-Compliance in Washington

Washington treats tuberculosis testing violations as a serious regulatory matter, not a paperwork technicality. State law classifies these violations severely: violation of the state animal health laws is a gross misdemeanor and also authorizes civil enforcement actions. WSDA’s civil penalty schedule under WAC 16-90-030 spells out specific dollar amounts tied to specific violations.

Failing to test before bringing cattle into Washington falls into the most serious penalty category. A “disease violation” is a violation of animal health statute and rules that causes a threat to Washington’s livestock industry and includes the failure to obtain required testing and vaccinations prior to entry into Washington state, and WAC 16-54-085’s domestic bovine tuberculosis requirements are explicitly listed under this category. Some violations carry a fixed civil penalty regardless of history: a one-thousand-dollar civil penalty will be issued regardless of the number of prior violations for violations including restricted feedlot rules, importation of a foreign or transboundary animal disease, and all quarantine and hold order violations.

WSDA doesn’t need to give advance warning before assessing these fines in the most severe cases. The department may assess a civil penalty for these violations without first issuing a notice of correction. There is some flexibility for producers who come forward on their own, though. The department reserves the right to decrease the civil penalty assessed for a violation by up to one hundred dollars in circumstances that include voluntary disclosure of a violation or voluntary taking of remedial measures.

State officials also hold short-term enforcement tools that can be deployed immediately, before any hearing takes place. The WSDA Director may issue hold orders for up to seven days for disease control purposes, require permits for import of animals with or exposed to reportable diseases, and require immediate reporting of livestock infected with or exposed to certain diseases. Given the stakes, producers importing cattle for a hunting camp, ranch operation, or exhibition should treat testing documentation with the same seriousness as their hunting license requirements in Washington paperwork — both are checked, and both carry real penalties for gaps.

Key Insight: A single missing test result can trigger both a disease violation and a procedural violation simultaneously — one for the untested animal, and another for incomplete CVI documentation. WSDA’s penalty structure treats these as separate infractions.

Washington’s accredited-free status is not a permanent guarantee; it depends on continued compliance from every cattle owner who moves an animal across the state line. Understanding which animals require testing, using only approved methods performed by accredited veterinarians, and keeping accurate CVI paperwork are the three habits that keep both individual herds and the entire state out of quarantine and penalty territory. When in doubt about a specific animal’s testing status, contact WSDA or an accredited veterinarian before the animal moves, not after.