Brucellosis Laws in Pennsylvania: What Livestock Owners Need to Know

Brucellosis may be rare in Pennsylvania today, but the regulations designed to keep it that way are very much active. Brucellosis is one of the most serious diseases to affect livestock, resulting in decreased milk production, weight loss, loss of young, infertility, and lameness — and because the disease spreads rapidly and is transmissible to humans, it poses a serious public health threat. If you raise cattle, bison, goats, or swine in the Keystone State, understanding the state’s brucellosis framework is not optional.

Pennsylvania has invested decades in eradicating this disease, and the rules governing vaccination, testing, movement, reporting, and quarantine all exist to protect that hard-won status. This guide walks you through every layer of Pennsylvania’s brucellosis laws so you know exactly what is expected of you as a livestock owner.

What Is Brucellosis and Why It Is Regulated in Pennsylvania

Brucellosis is caused by a group of bacteria in the genus Brucella. Three species cause the most concern: B. abortus, principally affecting cattle and bison; B. suis, principally affecting swine and reindeer but also cattle and bison; and B. melitensis, principally affecting goats — though B. melitensis is not currently found in the United States.

Brucellosis is commonly transmitted to susceptible animals by direct contact with infected animals or with an environment contaminated by discharges from infected animals. Aborted fetuses, placental membranes or fluids, and other vaginal discharges are all highly contaminated with infectious Brucella organisms. Cows may lick those materials or ingest the disease-causing organisms through contaminated food or water.

Despite occasional exceptions, the general rule is that brucellosis is carried from one herd to another by an infected or exposed animal — most often when a herd owner purchases replacement cattle or bison that are infected or have been exposed to infection prior to purchase.

The disease is also a serious zoonotic concern. Brucellosis is a zoonotic disease, meaning humans can become infected by coming into contact with infected animals or contaminated animal products. Though uncommon in the United States, brucellosis can cause a debilitating illness in humans called undulant fever. Veterinarians, hunters, cattle farmers, slaughterhouse workers, wildlife biologists, and people who drink raw milk are at greatest risk of exposure.

Under Pennsylvania law, brucellosis — a disease primarily affecting cattle, swine, sheep, and goats caused by Brucella abortus, Brucella melitensis, or Brucella suis — has been formally declared a dangerous transmissible disease by the Department. That designation gives the Pennsylvania Department of Agriculture (PDA) broad authority to regulate testing, vaccination, movement, and quarantine across the state.

If you manage other animals in Pennsylvania, it is also worth reviewing related state animal laws, such as goat ownership laws in Pennsylvania and beekeeping laws in Pennsylvania, which may intersect with disease reporting obligations.

Pennsylvania’s Brucellosis Classification Status

States are designated brucellosis Class Free when none of their cattle or bison are found to be infected for 12 consecutive months under an active surveillance program. Pennsylvania has been classified as a Class Free state since April 1, 1983.

That classification is recognized at both the state and federal levels. Under 9 CFR § 78.43, Pennsylvania is listed among the validated brucellosis-free states, alongside all other U.S. states, Puerto Rico, and the U.S. Virgin Islands. This federal validation carries real consequences for how animals entering and leaving Pennsylvania are treated under interstate commerce rules.

The federal brucellosis regulations in 9 CFR Part 78 provide a system for classifying states according to the rate of Brucella abortus infection and the general effectiveness of a brucellosis control and eradication program. The classifications are Class Free, Class A, Class B, and Class C — and restrictions on moving cattle and bison interstate become less stringent as a state approaches or achieves Class Free status.

The PDA’s Division of Animal and Poultry Health develops test programs for regulating diseases such as brucellosis and provides disease control programs to help prevent these diseases from entering Pennsylvania. Staff members evaluate health certificates for both interstate and intrastate movement to ensure that animals in Pennsylvania are healthy and have met necessary health requirements.

To maintain certified free state status, infected herds must be tested within 6 months unless positive legal action has been taken by the state against owners to require tests. Milk ring test (MCT) reactor herds must be tested or quarantined within 30 days, and if quarantined, the herd must be tested within 6 months.

To understand how Pennsylvania’s approach compares to neighboring states, you may find it helpful to review brucellosis laws in Michigan and brucellosis laws in Minnesota, both of which also hold Class Free status.

Vaccination Requirements in Pennsylvania

Pennsylvania’s vaccination rules are specific about which vaccine is authorized and who may administer it. Under 7 Pa. Code, Strain RB 51 vaccine is designated as the only brucellosis vaccine authorized for use within the Commonwealth.

Strain 19 vaccine may only be used with the express written permission of the Pennsylvania State Veterinarian. Requests for permission to administer Strain 19 vaccine must be made in writing on a form provided by the Department. The State Veterinarian may request additional information as necessary to assure the health of the animal and to prevent disease. A written approval or denial of the request will be provided within 3 working days of receiving the written request and all necessary information.

The shift away from Strain 19 was deliberate. Continued use of Strain 19 vaccine results in low but significant numbers of false positive animals, which creates a regulatory burden and expense for the cattle industry and the Department. Strain 19 brucellosis vaccine can also cause infection in humans and has been a health risk that veterinary practitioners have faced over the years.

The RB51 vaccine provides a significant level of protection — approximately 70 to 80 percent effective — and is also very effective at preventing abortions, which helps prevent further disease transmission. RB51 is available only through an accredited veterinarian, state animal health official, or federal area veterinarian in charge.

The transition to RB 51 broadened the age range for vaccination of calves from the former 4-to-8-month range to a 4-to-12-month range. This gives producers more flexibility in scheduling vaccinations around other herd management activities.

One important timing rule governs when vaccinated animals can be tested. Animal herds in which a vaccine, bacterin, serum, or other biologic has been used may not be bled for a brucellosis test within 60 days of the date of use for cattle. Plan your vaccination and testing schedules accordingly to avoid compliance gaps.

Testing Requirements for Cattle and Bison in Pennsylvania

Testing is the backbone of Pennsylvania’s brucellosis surveillance system. The state’s rules specify who may collect samples, how those samples must be submitted, and what happens while results are pending.

Diagnostic tests for brucellosis must be requested using official serology and tuberculosis test report Form AAI-11. These requests must be sent with blood samples to the Department of Agriculture Laboratory in Summerdale, Pennsylvania. Form AAI-11 must contain adequate identification of the animal bled and the complete name and address of the owner.

Only veterinarians officially approved by the Department or USDA-APHIS are permitted to collect blood for an official brucellosis test from any species of animal. Animals may not be moved from the owner’s premises from the time they are bled until the report of the test results is received.

Blood for agglutination tests must be collected from animals 6 months of age and older, except for vaccinated animals between the ages of 6 and 18 months. Breeding swine over 6 months of age must be bled to qualify for herd validation or when required for brucellosis trace-back purposes.

For raw milk operations, testing requirements are even more rigorous. A raw milk permit holder must, at intervals of no greater than 13 months, provide the Department confirmation from a licensed veterinarian that the animal or herd from which raw milk is produced has been determined to be free from brucellosis by annual blood tests conducted in accordance with Chapter 7 of the Pennsylvania brucellosis regulations.

The Department reserves the right to blood test animals for brucellosis at any time. It is unlawful for a person to interfere, refuse to confine animals so as to allow testing without undue burden, or to fail to present domestic animals or poultry for testing by the Department after reasonable notice has been given.

Interstate and Intrastate Movement Rules in Pennsylvania

Pennsylvania’s movement rules vary significantly depending on where the animals originate. The state’s Class Free status simplifies some requirements for animals coming from other free states, but imposes strict conditions on animals from lower-classification states.

Importing Animals Into Pennsylvania

Tests will not be required if the animal originates from a certified brucellosis-free herd. Animals originating from a brucellosis-free state may enter Pennsylvania without prior brucellosis tests.

For cattle and buffalo (bison) imported from a herd in a free state, test-eligible animals must be tested negative within 30 days prior to entry.

The requirements escalate for animals from Class A states. Cattle and bison imported from a Class A state must originate from a herd that has been blood tested and found negative within 15 months (449 days) of entry but prior to 120 days of shipment. The individual test-eligible animals to be imported must be blood test negative within 30 days of shipment. The herd test dates and certified free herd number must appear on the health certificate.

Importing from Class B or Class C states triggers the most stringent requirements. A prior permit from the Department must be obtained by the importer. Animals must originate from and be members of a certified brucellosis-free herd. Imported animals must be quarantined upon entry, and a post-entry test of test-eligible animals must be conducted no sooner than 45 days nor longer than 120 days after importation. The herd test date, certified herd number, prior permit number, and a statement by an accredited veterinarian must appear on the health certificate.

Exhibition and Show Animals

Tests will not be required for exhibition animals if they originate from a certified brucellosis-free and accredited tuberculosis-free herd. Animals originating from a brucellosis-free state may enter without prior brucellosis tests. Test-eligible animals originating from brucellosis Class A, B, and C states must be brucellosis test negative within 60 days of the opening date of the show.

Herd Additions and Intrastate Movement

Additions to herds must be accompanied by valid health charts and verified by an accredited veterinarian on the record of herd change, and must meet the requirements for importation of cattle, goats, and buffalo. Animals officially vaccinated and under 18 months of age may enter a herd without a blood test but must be accompanied by a health certificate.

For context on how similar movement rules work in other Class Free states, see brucellosis laws in Missouri and brucellosis laws in Nebraska.

Reporting and Quarantine Requirements in Pennsylvania

When brucellosis is detected — or even suspected — Pennsylvania law requires swift, specific action. The quarantine and reporting framework in 7 Pa. Code Chapter 7 leaves little room for delay.

Mandatory Quarantine on Infected Herds

Herds where a brucellosis reactor has been disclosed on an official test will be placed under quarantine. Brucellosis-infected herds shall be placed under quarantine, and animals may not be moved from the herds for addition to other herds until the herds are credited with at least two consecutive negative blood tests. The first test shall be conducted 30 days after the removal of reactors and the cleaning and disinfecting of the premises. The second test shall be conducted at least 90 days after the first test.

A brucellosis quarantine is cancelled when the owner receives a quarantine release letter from the Department following completion of the required negative tests.

Reporting to State and Federal Authorities

Animal health professionals — including veterinarians, diagnostic laboratory personnel, public health officials, zoo and wildlife personnel, and others — must 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.

Pennsylvania law also requires that all brucellosis activities conducted privately or under agreements with program officials — such as performing vaccinations or serologic tests — be reported immediately to cooperating agencies and to the herd owner of record.

Herd Certification and Loss of Status

Herd certification status will be lost if reactors are disclosed in the herd and will not be renewed until the next annual negative test after quarantine revocation.

If suspicious vaccinates over 18 months or unvaccinated suspects are revealed by the annual blood test for brucellosis, the certification shall be void until the suspects are retested and found negative. If suspects are not available for retest, the entire herd shall be retested with negative results.

Certified herds classified as brucellosis ring test suspicious herds shall retain their status if a complete herd blood test is negative when applied within 30 days. Animals are ineligible for health charts during this period until a negative blood test is obtained.

Pennsylvania’s animal disease reporting framework is part of a broader set of animal laws in the state. For related compliance topics, you may also want to review animal cruelty laws in Pennsylvania and kennel zoning laws in Pennsylvania, which reflect the state’s wide-ranging approach to animal welfare and regulation.

Penalties for Brucellosis Violations in Pennsylvania

Pennsylvania takes enforcement of its brucellosis regulations seriously. Violations of the state’s Domestic Animal Law and the brucellosis-specific regulations in 7 Pa. Code Chapter 7 can result in civil penalties, criminal charges, and mandatory corrective action.

Interference With Testing

The Department reserves the right to blood test animals for brucellosis at any time. It is unlawful for a person to interfere with testing, refuse to confine animals so as to allow testing without undue burden, or to fail to present domestic animals or poultry for testing after reasonable notice has been given. Violations of this provision expose owners to enforcement action under the Domestic Animal Law, 3 Pa. C.S. Chapter 23.

Unauthorized Vaccine Use

Using Strain 19 vaccine without the express written permission of the Pennsylvania State Veterinarian is a direct violation of 7 Pa. Code § 7.31. Because Strain 19 can cause false positives on standard brucellosis tests and poses a human infection risk, unauthorized use is treated as a serious regulatory offense. Continued use of Strain 19 vaccine results in continued low but significant numbers of false positive animals, which creates a regulatory burden and expense for the cattle industry and the Department. Strain 19 brucellosis vaccine can also cause infection in humans and is a health risk that veterinary practitioners have faced.

Unlawful Movement of Animals

Moving animals in violation of quarantine orders or without required health certificates is among the most serious brucellosis violations under Pennsylvania law. Animals may not be moved from the owner’s premises from the time they are bled until the report of the test results is received. Moving animals during this window — or from a quarantined herd without a permit — is a direct violation of Chapter 7 and subject to penalties under the Domestic Animal Law.

Animals that originate in a herd in which brucellosis infection has been disclosed may not be eligible for importation into the Commonwealth unless the herd has passed two consecutive negative blood tests. Importing non-compliant animals exposes both the buyer and seller to enforcement action.

Penalties Under the Domestic Animal Law

Under 3 Pa. C.S. § 2389, violations of the Domestic Animal Law — which encompasses brucellosis regulations — can result in civil penalties of up to $1,000 per violation per day. More serious violations, particularly those involving willful interference with disease control efforts or fraudulent health certificates, may be prosecuted as misdemeanors under Pennsylvania law. The Department also has authority to seek injunctive relief to stop ongoing violations and to order the quarantine or destruction of animals presenting a disease risk.

For a broader picture of how Pennsylvania enforces its animal laws, see animal cruelty laws in Pennsylvania. You can also compare enforcement approaches in other states by reviewing brucellosis laws in Nevada.

If you have questions about your specific compliance obligations, contact the Pennsylvania Department of Agriculture’s Bureau of Animal Health and Diagnostic Services or consult with an accredited veterinarian familiar with the state’s livestock disease regulations. Staying current with 7 Pa. Code Chapter 7 and the Pennsylvania Department of Agriculture’s brucellosis page is the most reliable way to ensure your herd remains in full compliance.