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

Brucellosis is one of the most tightly regulated livestock diseases in the United States, and South Dakota is no exception. If you raise cattle or bison in the state, understanding how brucellosis laws work is not optional—it is a core part of responsible herd management and legal compliance.

South Dakota’s regulatory framework for brucellosis spans vaccination protocols, testing requirements, movement permits, mandatory reporting, and enforcement penalties. Whether you are importing breeding stock, moving animals across state lines, or managing a herd near wildlife corridors, the rules affect you directly. This guide walks you through every layer of South Dakota’s brucellosis regulations so you know exactly what is required and why.

What Is Brucellosis and Why It Is Regulated in South Dakota

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. It has significant consequences for animal health, public health, and international trade. That combination of impacts is precisely why state and federal governments regulate it so aggressively.

In its principal animal hosts, brucellosis causes loss of young through spontaneous abortion or birth of weak offspring, reduced milk production, and infertility. It can affect both animals and humans. For South Dakota’s cattle-dependent agricultural economy, those consequences translate directly into financial losses for producers across the state.

Brucellosis is a bacterial disease of domestic and wild animals that may be transmitted to humans. Everyone is susceptible and may get the disease if exposed. It is more likely to be found in people associated with cattle, pigs, sheep and goats, or people who drink raw milk or unpasteurized dairy products.

Human symptoms of brucellosis include irregular fever, headache, weakness, sweating, chills, weight loss, generalized aching, and other nonspecific flu-like symptoms. The time period is highly variable, but symptoms usually appear within 5 days to 5 months, commonly 1 to 2 months.

There is no economically feasible treatment for brucellosis in livestock. Because infected animals cannot be cured, the entire regulatory system is built around prevention, detection, and removal—making compliance with South Dakota’s brucellosis laws essential for every cattle and bison owner in the state. You can review brucellosis laws in Nebraska for a neighboring-state comparison, or see how brucellosis laws in Minnesota approach the same framework differently.

South Dakota’s Brucellosis Classification Status

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. South Dakota holds a brucellosis-free classification, which is a status it works actively to maintain.

States are designated brucellosis-free when they have no infected cattle or bison for 12 consecutive months under an active surveillance program, or additional surveillance measures in place around areas that have brucellosis-infected wildlife to ensure early detection of any disease spillover.

It is important to note that brucellosis is present in free-ranging bison and elk in Yellowstone National Park, Grand Teton National Park, and the area around those parks. This threatens the brucellosis status of the surrounding states and the health of their cattle and domestic bison herds. While South Dakota is not immediately adjacent to the Greater Yellowstone Area, the disease risk from wildlife movement is a persistent concern that shapes how the state’s Animal Industry Board approaches surveillance and regulation.

South Dakota livestock producers and state and federal animal health officials have worked together over the years to eliminate and/or control diseases such as brucellosis, tuberculosis, and scrapie using animal traceability information. Maintaining the brucellosis-free designation is not passive—it requires ongoing testing, surveillance, and producer cooperation.

For context on how other states in the region manage their own classification status, see brucellosis laws in Michigan and brucellosis laws in Missouri.

Vaccination Requirements in South Dakota

Vaccination is one of the primary tools South Dakota uses to protect its brucellosis-free status. The state’s vaccination framework is governed by rules promulgated by the South Dakota Animal Industry Board (SDAIB), which has authority under state law to set both intrastate and importation vaccination requirements.

The Animal Industry Board shall promulgate rules concerning vaccination requirements and procedures for the intrastate sale, loan, lease, and transportation of breeding animals, as well as the vaccination requirements and procedures for the importation of breeding animals. This means that if you are selling or moving breeding stock within South Dakota or bringing animals in from another state, vaccination documentation may be required.

There is a vaccine for brucellosis called RB51. Licensed for use in nonpregnant female cattle 4 to 12 months of age, the vaccine provides a significant level of protection—about 70 to 80 percent effective. It is also very effective at preventing abortions, which prevents further disease transmission.

RB51 is available only through an accredited veterinarian, state animal health official, or federal area veterinarian in charge. You cannot purchase or administer this vaccine on your own—it must be obtained and applied through a licensed professional.

• Vaccination applies to nonpregnant female cattle between 4 and 12 months of age
• The RB51 vaccine is the standard used in the United States for calfhood vaccination programs
• Female cattle or bison vaccinated as official calfhood vaccinates must be permanently identified by a tattoo and by an official vaccination eartag in the right ear
• Some states do not allow cattle or domestic bison to be moved interstate for breeding without a record of brucellosis vaccination—check destination-state requirements before any breeding-stock movement

Vaccination of calves with B. abortus Strain 19 or RB51 increases resistance to infection. Resistance may not be complete, and some vaccinated calves may become infected depending on severity of exposure. Vaccination reduces risk significantly but does not eliminate it, which is why ongoing testing and surveillance remain required even for vaccinated herds.

Testing Requirements for Cattle and Bison in South Dakota

Testing is the backbone of South Dakota’s brucellosis surveillance system. The South Dakota Animal Industry Board maintains an adequate surveillance system for disease by testing blood and tissue samples for brucellosis and tuberculosis from cattle and swine slaughtered. This slaughter surveillance is one of several layers of testing the state uses to detect any disease presence early.

VS Form 4-54, the Brucellosis Test Record for the Market Cattle Testing Program, is used for brucellosis tests conducted as part of the Market Cattle Testing Program. This program governs the testing of cattle and bison at markets (first point of concentration) or slaughter.

For individual herd testing, the standard federal form applies as well. VS Form 4-33, the Brucellosis Test Record, must be completed for each animal or herd tested, with a separate form required for each species tested.

When a complete herd blood test is required, the scope is clearly defined. A complete herd blood test must include all cattle or bison six months of age and older, except steers and spayed heifers, unless otherwise specified by a Designated Epidemiologist.

A certified brucellosis-free herd is one whose owner has been issued a certified brucellosis-free herd certificate signed by the appropriate state animal health official and the Veterinarian in Charge. Qualification methods include conducting at least two consecutive negative herd blood tests not less than 10 months nor more than 14 months apart.

Supplemental tests using more sensitive screening methods may be used in cattle in which the brucellosis status is unclear. Use of various tests improves the probability of detecting infected cattle that have remained in some herds as possible reservoirs of infection. If a standard test result is ambiguous—particularly in vaccinated animals—your veterinarian may recommend confirmatory testing.

Interstate and Intrastate Movement Rules in South Dakota

Movement rules are among the most practically important brucellosis regulations you will encounter as a South Dakota livestock owner. They apply whether you are bringing animals into the state, sending them out, or transporting them within South Dakota’s borders.

Importing Livestock into South Dakota

Import permits are valid for 15 days. All livestock entering South Dakota must have an official Certificate of Veterinary Inspection (CVI) stating the name, address, and phone number of the consignor; the name and address of the point of origination if different from the consignor; and the name, physical address, and phone number of the consignee.

No import permit is required on CVIs issued for domestic livestock using approved electronic systems such as GlobalVetLink, VSPS, VetSentry, and Sale Time Systems. Animals must be free of signs of infectious or contagious diseases.

Interstate Movement and Federal Traceability

Effective as of March 11, 2013, USDA’s animal disease traceability rule established general regulations for livestock that move interstate. Under the rule, unless specifically exempted, livestock moved interstate must be officially identified.

Livestock moved interstate must be officially identified and accompanied by an interstate certificate of veterinary inspection. For cattle and bison specifically, official identification options in South Dakota include RFID “840” tags (USDA-approved Animal Identification Number tags), breed registration tattoos when accompanied by a registration certificate, and National Uniform Ear Tagging System (NUES) tags.

Before testing for interstate shipment, obtain state-specific regulations by contacting the state animal health official’s office in the importing state. Requirements vary significantly by destination, and what South Dakota requires of incoming animals may differ from what another state requires of animals you are sending out.

Movement of Reactor and Exposed Animals

Each livestock auction agency must maintain one or more pens separate and apart from other pens for holding animals that show symptoms of any contagious, communicable, or infectious disease and for cattle branded and tagged as brucellosis reactors. These animals must be sold from these quarantine pens for slaughtering purposes only. Such pens must be marked as quarantine pens with the top rail painted yellow.

This rule directly affects how you handle any animal that tests as a brucellosis reactor at a South Dakota sale barn. The animal cannot be sold for any purpose other than slaughter, and it must be physically segregated from the rest of the sale population. You can find related South Dakota livestock compliance information in our guide to goat ownership laws in South Dakota.

Reporting and Quarantine Requirements in South Dakota

South Dakota’s disease reporting and quarantine system is designed to contain any brucellosis outbreak as quickly as possible. Both state and federal obligations apply once a case is suspected or confirmed.

Animal health professionals—including veterinarians, diagnostic laboratories, public health, zoo, or wildlife personnel, and others—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. If you are a veterinarian or livestock owner who suspects brucellosis, you are required to report it promptly.

An approved individual herd plan is a herd management and testing plan designed by the herd owner, the owner’s veterinarian if requested, and a state representative or APHIS representative to determine the disease status of animals in the herd and to control and eradicate brucellosis within the herd. The plan must be jointly approved by the state animal health official and the Veterinarian in Charge.

Once infection is confirmed, the quarantine process begins immediately. Once a herd is affected, animal health officials quarantine all infected and exposed cattle and bison and limit their movement to slaughter only. This quarantine is not discretionary—it is a mandatory regulatory action that removes your ability to sell, breed, or move animals until the situation is resolved.

• Brucellosis reactors must be branded and tagged as reactors before any movement
• Reactor animals may only move to federally inspected slaughter facilities or USDA-approved feedlots under permit
• If infection is suspected or confirmed, regulatory officials will contact you, the owner, or both, to develop a herd plan
• Exposed animals that are not confirmed reactors may also be subject to movement restrictions pending further testing

Maintenance of an efficient, reliable system of animal disease traceability is essential to decrease negative effects and to preserve animal health when a disease outbreak occurs in an area. Effective traceability can also limit the number of animal owners impacted by an outbreak and reduce the economic impact to herd owners and affected communities, as well as the livestock industry as a whole.

South Dakota’s reporting infrastructure is coordinated through the South Dakota Animal Industry Board in partnership with USDA APHIS. The SDAIB maintains a reportable disease list and current restriction notices on its website. You can also review how neighboring states handle similar obligations—see brucellosis laws in Nevada for a western-state comparison.

Penalties for Brucellosis Violations in South Dakota

South Dakota takes brucellosis compliance seriously, and the penalties for violations reflect the severity of the disease’s potential impact on the state’s livestock industry. Violations can arise from failure to test, improper movement of reactor animals, failure to report, or non-compliance with quarantine orders.

The regulations of the APHIS Brucellosis Eradication Program vary based on the brucellosis status of each state. Minimum standards are set forth in the Brucellosis Eradication Uniform Methods and Rules; however, some states have more restrictive requirements. South Dakota’s Animal Industry Board has authority to enforce both state-level requirements and applicable federal standards.

Under South Dakota Codified Laws Title 40, the Animal Industry Board is empowered to issue permits, conduct inspections, and enforce compliance across all aspects of the brucellosis program. Violations of the board’s rules—including those governing vaccination, testing, movement, and reporting—can result in:

• Civil fines assessed by the Animal Industry Board for regulatory non-compliance
• Mandatory quarantine of your entire herd at your expense pending investigation
• Loss of certified brucellosis-free herd status, requiring full re-qualification testing
• Seizure and condemnation of animals found to be in violation of movement or disposition rules
• Criminal misdemeanor charges under South Dakota law for knowing violations of livestock disease control statutes

Because treated animals cannot be distinguished from untreated carriers and pose ongoing transmission risk, antibiotic treatment of brucellosis is not permitted under regulatory programs in most countries. This means that once an animal is confirmed as a reactor, there is no pathway to treatment and return to the herd—the only legally compliant outcome is slaughter. Attempting to conceal a reactor animal or move it outside of permitted channels is a serious violation.

The only means of eliminating infection from individual cattle is removal of those animals from the herd. Management of brucellosis cases therefore centers on regulatory compliance and biosecurity rather than treatment of infected individuals. Understanding this reality helps explain why South Dakota’s enforcement approach is structured around strict documentation, movement controls, and mandatory reporting rather than treatment-based remediation.

For more information on South Dakota animal regulations that may intersect with your livestock operations, explore our guides on roadkill laws in South Dakota, beekeeping laws in South Dakota, and backyard chicken laws in South Dakota. If you have questions specific to your operation, contact the South Dakota Animal Industry Board directly or reach out to a USDA APHIS accredited veterinarian in your area.