Brucellosis Laws in Washington State: What Livestock Owners Need to Know
August 24, 2026
Brucellosis may be rare in Washington state today, but the regulations designed to keep it that way are very much in force. Whether you raise cattle, own bison, or move livestock across state lines, the rules governing vaccination, testing, movement, and disease reporting apply directly to you.
Understanding Washington’s brucellosis framework is not just a matter of legal compliance — it protects your herd, your neighbors’ herds, and the state’s agricultural economy. This guide walks you through every major requirement under Washington state law so you know exactly what is expected of you as a livestock owner.
What Is Brucellosis and Why It Is Regulated in Washington
Brucellosis — also known as contagious abortion or Bang’s disease — is a costly disease of livestock and wildlife caused by bacteria in the genus Brucella. The disease has significant consequences for animal health, public health, and international trade, and it occurs mainly in cattle, bison, and swine, but can also affect other animals such as cervids, goats, sheep, and horses — as well as people.
In cattle and bison, the primary bacteria of concern is Brucella abortus. On rare occasions, humans have been infected with brucellosis, usually by drinking unpasteurized milk from infected cows or by contact with infected birthing fluids and tissues. This zoonotic risk is a core reason the disease is treated as a public health matter, not just an agricultural one.
Symptoms in humans can include fever, headache, weakness, profuse sweating, chills, weight loss, and general achiness. Infections of organs including the liver, spleen, and lining of the heart may also occur. People with weakened immune systems, young children, pregnant individuals, or those with artificial heart valves are at higher risk of severe disease.
The brucellosis statutes and regulations in Washington were enacted pursuant to the state’s police power for the “public welfare” and the “public health” of the people of Washington. The Legislature recognized that the protection of the public health necessarily depends on control and eradication of the disease in animals. For Washington livestock owners, that legal foundation translates into real, enforceable obligations. You can learn more about how Washington approaches animal disease regulation through its broader pet and animal laws in Washington state.
Washington’s Brucellosis Classification Status
Washington was declared free of swine (pig) brucellosis in 1975 and of bovine (cow) brucellosis in 1988. That milestone placed Washington among the states that achieved Class Free status under the federal classification system managed by the USDA Animal and Plant Health Inspection Service (APHIS).
The brucellosis regulations in 9 CFR Part 78 provide a system for classifying states or portions of states according to the rate of Brucella abortus infection present and the general effectiveness of a brucellosis control and eradication program. The classifications are Class Free, Class A, Class B, and Class C — with states that do not meet the minimum standards for Class C status required to be placed under federal quarantine.
Restrictions on moving cattle and bison interstate become less stringent as a state or area approaches or achieves Class Free status. Washington’s Class Free standing means your cattle and bison face fewer interstate movement hurdles than animals from lower-classified states, but it does not eliminate Washington’s own intrastate testing and vaccination requirements.
All 50 states, Puerto Rico, and the U.S. Virgin Islands are brucellosis-free, except for the occasional spillover of cases occurring in livestock near the Greater Yellowstone Area due to bison and elk having the disease. Brucellosis is present in free-ranging bison and elk in Yellowstone National Park, Grand Teton National Park, and the area around those parks, which threatens the brucellosis status of the surrounding states and the health of their cattle and domestic bison herds. Washington is geographically removed from the Greater Yellowstone Area, but vigilance remains essential.
If you are interested in how neighboring states handle brucellosis regulation, you can compare Washington’s approach to brucellosis laws in Nevada or review brucellosis laws in Nebraska for a broader regional picture.
Vaccination Requirements in Washington
Washington maintains detailed vaccination requirements for female cattle, with specific rules governing who can administer vaccines, how animals must be identified, and how vaccinations must be reported to the state.
Calfhood Vaccination
An “official calfhood vaccinate” means female cattle between four and twelve months of age that are vaccinated with brucellosis vaccine at a calfhood dose (2cc subcutaneously) and officially individually identified. Cattle vaccinated with the RB-51 strain of vaccine must be permanently identified with a tattoo in the right ear that bears the USDA registered V-shield preceded by the letter R followed by the last digit of the year of vaccination.
Adult Vaccination
An “official Washington adult vaccinate” means female cattle over the age of twelve months that have resided in Washington state for ninety days or more and are vaccinated with a dose of brucellosis vaccine (2cc subcutaneously) under directions issued by the director.
Official adult vaccinates must not be pregnant and must have prevaccination blood samples for brucellosis submitted on USDA form number VS4-33 to the office of the state veterinarian. An official adult vaccinate must be vaccinated with 2cc subcutaneous RB-51 Brucella vaccine, permanently identified with individual official identification, and permanently identified as a vaccinate by an adult vaccination tattoo in the right ear.
Reporting Requirements for Vaccinations
An official vaccination report of all brucellosis vaccinations must be made to the department within thirty days of vaccination by the accredited veterinarian who performed the vaccination. The vaccination report must be made on an approved report form (USDA form number VS 4-26) issued by the department for the purpose of individually identifying the cattle and recording official brucellosis vaccinations.
All vaccinations must be performed by a licensed accredited veterinarian or federal or state employed veterinarian and are not official until they are reported to the department. Veterinarians must record all vaccinations in a ledger that records the owner of the animal, official individual identification numbers, and the date of vaccination. These records must be maintained for seven years.
In addition to the rules adopted in Washington’s brucellosis chapter, the Washington State Department of Agriculture adopts the procedures and methods of the USDA Brucellosis Eradication Uniform Methods and Rules, effective October 1, 2003. This means federal standards set a floor that Washington’s rules build upon. You can review the USDA APHIS bovine brucellosis program for additional context on national vaccination standards.
Testing Requirements for Cattle and Bison in Washington
Washington’s testing requirements apply both to cattle and bison already within the state and to animals entering from other states or countries. The requirements differ based on the animal’s sex, age, and intended use.
Testing for Cattle and Bison Within Washington
Under WAC 16-86, any cattle or bison in Washington may be subject to official brucellosis testing as part of the state’s ongoing surveillance program. If owners refuse to allow the department to test for diseases provided for in the brucellosis chapter, all cattle or bison will be regarded as a menace to the health of livestock, and the premises on which they are kept will be immediately quarantined and no animals or products of these animals may be removed from the premises.
Testing Requirements for Animals Entering Washington
When you bring cattle into Washington from another state, testing requirements depend on the animal’s characteristics:
- All females over the age of 20 months require a negative brucellosis test listed on the Certificate of Veterinary Inspection (CVI).
- All bulls over the age of 6 months require a negative brucellosis test listed on the CVI.
- The cattle need to be tested no more than 60 days before entry.
- Cattle going to exhibition and then returning home must meet the same requirements as cattle going to private ownership. Rodeo stock are not exempt from testing requirements.
Cattle that have not met the department’s brucellosis requirements may enter a Category 1 Restricted Holding Facility in Washington state with an entry permit, a Certificate of Veterinary Inspection, and official individual identification when required, until testing and vaccination requirements have been met. The Category 1 Restricted Holding Facility must be approved by the director and operated in accordance with chapter 16-30 WAC.
For livestock owners who also import other types of animals, Washington’s pet import laws in Washington cover the requirements for non-livestock species entering the state.
Interstate and Intrastate Movement Rules in Washington
Moving cattle and bison — whether into Washington from another state or within Washington itself — triggers specific permitting and documentation requirements under state law.
Interstate Movement Into Washington
All cattle and bison coming into the state of Washington are required to enter with a permit. Permits can be obtained by veterinarians or brand inspectors online or by calling 360-902-1878. All cattle require a CVI and an entry permit. All sexually intact cattle over the age of 18 months must be individually identified on the CVI.
Adult vaccinated domestic cattle that are identified by a legible vaccination tattoo and official individual identification will be allowed entry into Washington state if the state of origin allows adult vaccination and is of the same brucellosis class or higher. This means you cannot simply bring adult-vaccinated cattle from a lower-classified state and expect them to qualify for entry without additional scrutiny.
The following table summarizes the key testing and documentation requirements for cattle entering Washington from domestic sources:
| Animal Category | Brucellosis Test Required | Additional Documentation |
|---|---|---|
| Females over 20 months | Yes — negative test on CVI | CVI, entry permit, official ID |
| Bulls over 6 months | Yes — negative test on CVI | CVI, entry permit |
| Heifer calves (4–12 months) | No — vaccination required instead | CVI, entry permit; may go to approved sale yard |
| Cattle to exhibition/rodeo | Yes — same as private ownership | CVI, entry permit |
| Cattle to Category 1 RHF | Not required at entry — must meet requirements while at facility | CVI, entry permit, official individual ID |
Interstate Movement Out of Washington
All cattle leaving Washington state must be accompanied by a brand inspection. The receiving state’s rules will then govern any additional testing or documentation requirements. You should contact the destination state’s department of agriculture to confirm what those requirements are before moving animals across state lines.
Intrastate Movement Within Washington
Washington’s brucellosis rules under WAC 16-86 also govern the movement of cattle and bison within the state, particularly when those animals have been quarantined or are subject to an active herd plan. Cattle or bison that test positive to the brucellosis test must not be sold or offered for sale except for immediate slaughter, and quarantined cattle and bison may only be moved when accompanied by an official USDA form number VS1-27.
If you move livestock within Washington and want to understand the broader legal landscape for animal ownership in the state, resources on goat ownership laws in Washington and rooster laws in Washington provide useful context on how the state regulates different livestock categories. For a comparison of how other states structure interstate movement rules, see brucellosis laws in Minnesota and brucellosis laws in Missouri.
Reporting and Quarantine Requirements in Washington
Washington’s brucellosis framework includes mandatory reporting obligations and a structured quarantine process that activates the moment a positive test result is confirmed in your herd.
Mandatory Reporting
Animal health professionals — including veterinarians, diagnostic laboratories, and public health and wildlife personnel — are required to report diagnosed or suspected cases of nationally listed reportable animal diseases to APHIS Area Veterinarians in Charge and to the state animal health official as applicable under state reporting regulations.
Brucella canis infections in animals are reportable by veterinarians to the Washington State Department of Agriculture. For bovine brucellosis, the same reporting obligations apply. If your veterinarian suspects or confirms brucellosis in your herd, they are legally required to notify the WSDA without delay.
Quarantine Process
Any herd of cattle or bison in which brucellosis reactors are found will be quarantined. Positive or reactor classification is based on standards listed in the USDA Brucellosis Eradication Uniform Methods and Rules, effective October 1, 2003.
Once your herd is quarantined, the path to release is clearly defined:
- The quarantine will be released when the entire quarantined herd has passed two consecutive negative blood tests without reactors.
- The first test must be not less than thirty days following removal of all reactors from the herd.
- The second test must not be less than ninety days nor more than one year following the date of the previous test.
Steers, spayed heifers, officially vaccinated dairy cattle under twenty months of age, and officially vaccinated beef animals under twenty-four months of age need not be tested as part of the quarantine release process.
Director’s Authority to Order Slaughter
As provided under RCW 16.36.090, the director may order the slaughter or destruction of any cattle affected with or exposed to brucellosis. Under RCW 16.36.096, subject to the availability of amounts appropriated for this specific purpose, owners whose animals are slaughtered under such an order may be eligible for indemnity payments.
Washington’s broader animal disease framework also intersects with wildlife management. If you encounter sick or dead wildlife on or near your property, the WSDA and Washington Department of Fish and Wildlife have protocols in place. You can learn more about how Washington handles wildlife-related issues through its wildlife removal laws in Washington.
Penalties for Brucellosis Violations in Washington
Washington takes brucellosis compliance seriously, and the penalty structure under WAC 16-90-030 reflects that. Violations are categorized by severity, with disease-related violations — including brucellosis — treated as among the most serious offenses in the state’s livestock regulatory framework.
Disease Violations
A “disease violation” is a violation of animal health statute and rules that causes a threat to Washington state’s livestock industry and includes the failure to obtain required testing and vaccinations prior to entry into Washington state. Disease violations include, but are not limited to, violations of specific statutes and rules. WAC 16-54-083, governing domestic and foreign bovine brucellosis requirements, is explicitly listed among those disease violations.
Civil Penalty Structure
The following table outlines Washington’s civil penalty tiers for livestock-related violations under WAC 16-90-030:
| Violation Type | Penalty | Notes |
|---|---|---|
| Disease violations (first offense) | Scaled civil penalty | Includes failure to vaccinate or test prior to entry |
| Quarantine and hold order violations | $1,000 minimum civil penalty | Applies regardless of number of prior violations |
| Importation of a foreign animal disease or transboundary diseased animal | $1,000 civil penalty | Issued regardless of prior violation history |
A one thousand dollar civil penalty will be issued regardless of the number of prior violations for the importation of a foreign animal disease or “transboundary” diseased animal — defined as a disease that has been eradicated within the borders of the United States that would cause an economic loss if detected — and for all quarantine and hold order violations under chapter 16.36 RCW.
Criminal Penalties and Injunctive Relief
Beyond civil penalties, Washington law provides for criminal enforcement and court-ordered injunctions. Upon learning of violations of state regulations pertaining to the movement of cattle restricted by state quarantine, the Director is under a duty to enjoin the violator from continuing such violations and/or bring a criminal action. This means that serious or repeated violations can escalate from administrative penalties to criminal prosecution.
Washington’s enforcement approach to brucellosis violations mirrors its broader stance on animal health compliance. For context on how the state handles other animal-related legal matters, you can review dog bite laws in Washington or explore beekeeping laws in Washington for examples of how the state structures regulatory obligations and penalties across different animal categories. If you want to see how neighboring states structure their penalty frameworks, brucellosis laws in Michigan provides a useful point of comparison.
Washington’s brucellosis regulations represent a coordinated effort between state and federal authorities to protect the livestock industry, public health, and the state’s Class Free status. Your obligations as a livestock owner — from vaccinating calves and testing imported animals to reporting suspected cases and complying with quarantine orders — are the practical foundation of that protection. Staying current with WSDA requirements and working with a licensed accredited veterinarian for all official vaccinations and testing is the most reliable way to remain in compliance and keep your herd, and Washington’s agricultural standing, secure. You can reach the Washington State Department of Agriculture’s animal health division at agr.wa.gov for the most current permit and entry requirement information.