Brucellosis Laws in Oklahoma: What Cattle and Bison Owners Need to Know

If you raise cattle or bison in Oklahoma, understanding brucellosis regulations is one of the most important compliance responsibilities you have as a livestock owner. Brucellosis is a serious bacterial disease that can spread quickly through herds and, in some cases, to humans — which is exactly why state and federal agencies treat it with such regulatory seriousness.

Oklahoma has maintained a strong disease-control track record, and the state’s brucellosis laws reflect a framework built around prevention, surveillance, and rapid response. Whether you are moving animals across state lines, vaccinating calves, or responding to a suspected case, knowing the rules in advance can save you from costly penalties and herd disruptions.

This article walks you through every major aspect of Oklahoma’s brucellosis regulations — from the state’s current classification status to quarantine procedures and the consequences of non-compliance.

What Is Brucellosis and Why It Is Regulated in Oklahoma

Brucellosis, also called undulant fever, is an infectious disease caused by various species of the bacteria Brucella. The disease primarily affects animals but occasionally causes illness in humans who have contact with infected animals or who consume food products from infected animals.

Brucellosis typically infects sheep, goats, cattle, deer, elk, pigs, dogs, and several other mammals. For Oklahoma’s agricultural sector — one of the most cattle-intensive in the nation — the disease poses a direct economic threat. Infected herds face restricted movement, mandatory testing, and potential depopulation orders, all of which carry significant financial consequences.

Brucellosis can cause a range of symptoms that may include fever, sweats, headache, back pain, and physical weakness. Severe infections of the central nervous system or lining of the brain may occur. The disease can also cause long-lasting symptoms that include recurrent fever, joint pain, and fatigue.

Brucellosis is a reportable disease in Oklahoma. This means that any confirmed or suspected case — whether in livestock or humans — must be reported to the appropriate state authorities. The Oklahoma Department of Agriculture, Food, and Forestry (ODAFF) oversees the animal health side of brucellosis regulation, working in coordination with the USDA’s Animal and Plant Health Inspection Service (APHIS).

If you also manage other livestock species in Oklahoma, it is worth reviewing related animal laws such as goat ownership laws in Oklahoma and beekeeping laws in Oklahoma, as different species carry different regulatory requirements.

Oklahoma’s Brucellosis Classification Status

Oklahoma holds the highest possible brucellosis classification under the federal system: Class Free (also referred to as Validated Brucellosis-Free status). The USDA amended brucellosis regulations concerning the interstate movement of cattle by changing the classification of Oklahoma from Class A to Class Free, having determined that Oklahoma meets the standards for Class Free status.

Under 9 CFR § 78.43, Oklahoma is listed among the validated brucellosis-free states, a designation that is confirmed in the current Electronic Code of Federal Regulations. The eCFR title covering brucellosis designations was last amended as of July 1, 2025.

Changing Oklahoma’s brucellosis status from Class A to Class Free promotes economic growth by reducing certain testing and other requirements governing the interstate movement of cattle from the state. In practical terms, this means that cattle leaving Oklahoma for other states are not automatically subject to brucellosis testing requirements that apply to animals from lower-classified states.

For initial classification or reclassification as Class Free, all cattle herds in the state or area must have remained free of Brucella abortus for 12 consecutive months, and the state must have a cattle herd infection rate of 0.0 percent, or 0 herds per 1,000.

To understand how other states approach this classification, you can compare Oklahoma’s framework with brucellosis laws in Nebraska or brucellosis laws in Missouri.

Vaccination Requirements in Oklahoma

Although Oklahoma’s Class Free status reduces the urgency of mandatory mass vaccination campaigns, brucellosis vaccination remains a regulated activity with strict procedural requirements. The rules governing how, when, and by whom vaccination can be performed are codified in Oklahoma Administrative Code (OAC) Title 35, Chapter 15.

An “official vaccinate” is defined as a female bovine or bison animal vaccinated against brucellosis with an approved brucella vaccine between four and twelve months of age. Vaccination outside this age window does not qualify an animal for official vaccinate status under state or federal definitions.

All vaccination must be conducted under the supervision of a federal or state veterinary official or accredited veterinarian. Vaccinated animals must be permanently identified as vaccinates and reported at the time of vaccination to the appropriate state or federal agency cooperating in the eradication of brucellosis.

An “approved brucella vaccine” means a product that is approved by and produced under license of the United States Department of Agriculture for injection into cattle or bison to enhance their resistance to brucellosis. You may not use unapproved products and claim official vaccinate status for your animals.

• Vaccination must be performed by or under the supervision of an accredited veterinarian
• Only USDA-licensed brucella vaccines qualify for official vaccinate designation
• Female bovines and bison must be vaccinated between 4 and 12 months of age
• Vaccinated animals must receive permanent identification markings
• Vaccination records must be reported to the appropriate state or federal agency at the time of vaccination

Certified Brucellosis-Free Herd status is valid for 12 months, meaning that even certified herds must maintain ongoing compliance with vaccination and testing schedules to retain their status year over year.

Testing Requirements for Cattle and Bison in Oklahoma

Testing requirements in Oklahoma are tied directly to the purpose of movement, the classification of the herd, and the origin of the animals. Because Oklahoma holds Class Free status, routine pre-movement testing for most cattle is not required — but specific circumstances still trigger mandatory testing obligations.

A “herd test” means a test that includes all animals over six months of age except steers and spayed heifers. This definition is important because it determines which animals in your herd are subject to testing when a herd-level test is ordered or required.

A “certified brucellosis-free herd” is a herd of cattle or bison which has qualified for and whose owner has been issued a certified brucellosis-free herd certificate signed by the appropriate state animal health official and the Veterinarian in Charge.

The following table summarizes key testing scenarios and their requirements:

Cattle entering Oklahoma require official USDA-approved identification and a Certificate of Veterinary Inspection (CVI) issued within 30 days of transport. Additional testing is needed for cattle from states with brucellosis or tuberculosis concerns.

All bulls entering Oklahoma must also meet applicable tuberculosis and brucellosis entry requirements, and the shipment must have a valid Certificate of Veterinary Inspection.

Interstate and Intrastate Movement Rules in Oklahoma

Movement rules are among the most operationally significant aspects of brucellosis law for Oklahoma livestock owners. Whether you are buying, selling, or relocating animals within or outside the state, the regulations governing how animals must be identified, documented, and tested before movement are strictly enforced.

Exposed animals — meaning animals that are part of a known affected herd or have been in contact with brucellosis reactors in marketing channels — are considered to be exposed regardless of blood test results and must be placed under quarantine and restricted pending slaughter or testing after return to the herd of origin.

These animals must be identified with a hot iron letter “S” brand on the tailhead, at least 2×2 inches in size, prior to movement from the premises. This branding requirement ensures that exposed animals are visually identifiable throughout the marketing and movement chain.

A “permit” is an official document (USDA VS Form 1-27 or comparable state form) that is required to accompany “B” branded cattle, “S” branded cattle, and exposed cattle moved under official seal, issued by a veterinary services representative, state representative, or accredited veterinarian that lists the official identification, USDA backtag, registration number, reactor tag number, owner’s name and address, origin and destination, number of animals covered, and the purpose of the movement.

For intrastate movement, Oklahoma’s rules align with the USDA Uniform Methods and Rules (UM&R), which contain minimum standards for certifying herds, classifying states and areas, and detecting, controlling, and eradicating brucellosis, as well as minimum brucellosis requirements for the intrastate and interstate movement of cattle and bison.

• Reactor cattle must be branded with a “B” on the left hip before movement
• Exposed cattle must carry the “S” brand on the tailhead
• All restricted animal movements require an official permit (VS Form 1-27 or equivalent)
• Commuter herds operating across state lines must comply with both states’ entry requirements
• Rodeo bulls have specific movement exemptions but must still meet entry requirements when changing ownership

A “commuter herd” means all cattle under common ownership or supervision, that are located on one or more premises in two or more states, with an interchange or interstate movement of animals between premises as part of the normal farming, breeding, or ranching operation without a change of ownership.

For a broader look at how neighboring states handle similar movement requirements, see brucellosis laws in Minnesota and brucellosis laws in Michigan.

Reporting and Quarantine Requirements in Oklahoma

Oklahoma’s brucellosis reporting and quarantine framework is designed to contain any potential outbreak as quickly as possible and to protect the state’s Class Free designation. If you suspect brucellosis in your herd, you are legally obligated to report it — delay is not an option.

Brucellosis is a reportable disease in all states and territories; it is mandatory that disease cases be reported to state and territorial jurisdictions when identified by a health provider, hospital, or laboratory. On the animal health side, this obligation extends to accredited veterinarians and herd owners who observe clinical signs or receive positive test results.

An “affected herd” means a herd of cattle that has had a brucellosis reactor disclosed from an on-farm test or is the herd of origin of a market cattle identification brucellosis reactor from which a field strain Brucella abortus bio-variety has been isolated. Once a herd is classified as affected, a cascade of regulatory obligations is triggered.

Once brucellosis is confirmed or suspected in a herd, Oklahoma law and USDA UM&R require the following steps:

1. Immediate notification — The herd owner and/or attending veterinarian must notify ODAFF and USDA APHIS of the reactor finding
2. Quarantine placement — The affected premises are placed under an official state or federal quarantine order restricting all animal movement on and off the property
3. Herd investigation — A designated brucellosis epidemiologist conducts a full epidemiologic investigation to trace the source and spread of infection
4. Individual herd plan — ODAFF and APHIS develop a written herd plan specifying testing, vaccination, and movement restrictions for the affected operation
5. Retesting — All test-eligible animals in the herd are retested at intervals specified in the herd plan
6. Depopulation (if required) — In severe cases, infected herds may be subject to depopulation under state and federal authority

Disease control and eradication measures include quarantines to stop the movement of possibly infected or exposed animals, testing and examination to detect infection, destruction of infected animals to prevent further disease spread, treatment to eliminate parasites, vaccination in some cases, and cleaning and disinfection of contaminated premises.

For livestock, quarantine periods depend on disease risk. Cattle from states with brucellosis or tuberculosis concerns may be held for additional testing.

Oklahoma’s reporting obligations also intersect with human health. Brucellosis is a reportable disease in Oklahoma for both animal and human cases, meaning the Oklahoma State Department of Health coordinates with ODAFF when zoonotic exposure is suspected.

If you manage other regulated animals in the state, you may also want to review rooster laws in Oklahoma and backyard chicken laws in Oklahoma, as poultry operations can intersect with broader livestock disease reporting frameworks.

Penalties for Brucellosis Violations in Oklahoma

Failing to comply with Oklahoma’s brucellosis laws carries real legal and financial consequences. The state’s penalty framework is designed to deter non-compliance and ensure that violations are taken seriously — particularly when they risk spreading disease to neighboring operations.

Oklahoma Statutes Title 2 (Agriculture) contains the primary statutory authority for brucellosis enforcement. Key provisions include:

• Oklahoma Statutes § 2-6-99 — Governs the quarantine of livestock infected with brucellosis and their required disposition
• Oklahoma Statutes § 2-6-100 — Addresses brucellosis eradication requirements for livestock owners and indemnity payment structures
• Oklahoma Statutes § 2-6-101 — Covers the certification of brucellosis-free herds and counties

Violating Oklahoma’s animal import and movement regulations can lead to fines, quarantine, or legal consequences. The Oklahoma Administrative Code grants regulatory agencies authority to impose penalties for missing documentation, transporting animals without permits, or introducing prohibited species.

Fines can reach thousands of dollars per violation, especially for repeat offenders.

Failure to comply with quarantine orders can result in penalties, including confiscation or euthanasia if the animal poses a significant health risk.

The following table outlines the types of violations and their potential consequences under Oklahoma and federal brucellosis law:

Beyond financial penalties, violations can result in the loss of your herd’s certified brucellosis-free status — a designation that directly affects the marketability and movement freedom of your animals. Whether transporting livestock, pets, or exotic species, failing to meet Oklahoma’s requirements can result in fines, quarantine, or denial of entry.

For a broader view of how animal regulations are structured across state lines, see brucellosis laws in Nevada or explore United States laws on exotic pets for context on how different categories of animals are regulated nationally.

If you have questions about specific penalty provisions or enforcement actions, consulting with an attorney familiar with Oklahoma agricultural law or contacting ODAFF’s Animal Industry division directly is the most reliable course of action. You can also review related Oklahoma animal regulations such as dog leash laws in Oklahoma, pit bull laws in Oklahoma, and kennel zoning laws in Oklahoma to understand the full scope of the state’s animal regulatory environment.