Livestock Disease Reporting in Montana: Rules Every Producer and Veterinarian Must Know

Montana’s livestock industry is one of the state’s most vital economic pillars, and protecting it from disease outbreaks starts with a single, non-negotiable obligation: timely, accurate disease reporting. Whether you run a cattle ranch on the high plains, manage a sheep operation in the Bitterroot Valley, or work as an accredited veterinarian serving rural producers, understanding Montana’s livestock disease reporting requirements is not optional — it is the law.

Failing to recognize and report a notifiable condition can allow disease to spread across county lines, compromise trading relationships, and trigger costly state or federal interventions. This guide walks you through every stage of the reporting process in Montana, from which diseases are on the mandatory list to what happens after your call reaches the state veterinarian’s office.

Reportable Livestock Diseases in Montana

Montana maintains a formal list of diseases that must be reported to state animal health authorities. The Montana Department of Livestock’s Animal Health Bureau is responsible for the prevention, control, and eradication of animal diseases, which includes safeguarding the health and food production capacity of the state’s livestock and poultry and preventing the transmission of animal diseases to humans. The reportable disease list is the foundation of that mission.

Diseases on Montana’s mandatory reportable list span multiple species and categories, including foreign animal diseases, zoonotic conditions, and economically significant production diseases. Key diseases that Montana producers and veterinarians must be aware of include:

• Brucellosis (Brucella abortus) — A bacterial disease primarily affecting cattle and bison, with major trade and public health implications. Regulations mandate routine health checks and vaccinations for diseases such as brucellosis and bovine tuberculosis, and all cattle over 12 months must be tested for brucellosis, with results documented and reported.
• Bovine Tuberculosis (bTB) — A respiratory bacterial disease with serious zoonotic potential, subject to ongoing state and federal eradication programs.
• Trichomoniasis (Tritrichomonas foetus) — A venereal disease of cattle caused by a protozoan parasite. Montana has designated areas with a high risk for trich exposure called Trichomoniasis Epizootic Areas (Trich EA), where testing is required for all non-virgin bulls sold, loaned, or leased within or from the Trich EA.
• Johne’s Disease (Paratuberculosis) — A chronic wasting condition in ruminants. Only 0.3% of Montana’s cattle herd was tested between 2017–2019, yet 146 premises were identified as having Johne’s disease, highlighting the importance of active surveillance and reporting.
• Chronic Wasting Disease (CWD) — Affects cervids including deer, elk, and moose. CWD was found among wild deer in Montana in 2017. Alternative livestock operations with cervids are subject to mandatory CWD surveillance requirements.
• Avian Mycoplasmosis — Including Mycoplasma gallisepticum and related strains affecting poultry flocks.
• West Nile Virus (WNV) — WNV is a viral infection that can cause encephalitis or meningitis and is spread by the bite of an infected mosquito. Confirmed equine and avian cases are reportable in Montana.
• Brucella canis — B. canis is a zoonotic reportable disease in Montana per Administrative Rule 32.3.104.
• Foreign Animal Diseases (FADs) — Including foot-and-mouth disease, highly pathogenic avian influenza, African swine fever, and other exotic conditions. Any suspicion of an FAD triggers an immediate mandatory investigation. The Department of Livestock tracks Foreign Animal Disease investigations by county; all cases in Q1 of FY25 were negative.
• Rabbit Hemorrhagic Disease Virus 2 (RHDV-2) — During Q1 of FY24, there were several investigations into potential foreign animal diseases in Montana, specifically Rabbit Hemorrhagic Disease (RHDV-2) in rabbits, with tests conducted in Park and Yellowstone Counties.
• Scrapie — A fatal prion disease of sheep and goats subject to a national eradication program.
• Equine Viral Arteritis (EVA) — A reportable equine respiratory and reproductive disease. For stallions that are known carriers of EVA in semen, the State Veterinarian must be officially notified prior to importation, and stallions testing positive must fax a copy of the lab report to the State Veterinarian’s office prior to a permit for import being issued.

For producers who also raise alternative livestock such as elk or deer on licensed ranches, the Alternative Livestock Program regulates alternative livestock ranches with elk, deer, and other cervidae for disease control and inspection for ownership, in cooperation with the Department of Fish, Wildlife and Parks. These operations face additional disease reporting and surveillance obligations beyond standard livestock requirements. You can also learn more about bovine diseases and zoonotic diseases that overlap with livestock reporting obligations.

Who Is Required to Report a Livestock Disease in Montana

Montana’s disease reporting obligations fall on multiple parties within the animal health system. Understanding your specific role ensures that no case slips through the cracks.

Health and safety regulations in Montana protect both animal welfare and public health, and the Montana Department of Livestock enforces measures against contagious diseases, conducting inspections and monitoring compliance to prevent outbreaks. This means the reporting obligation is not limited to veterinarians — producers themselves bear a direct legal responsibility.

The Animal Health and Food Safety Division is responsible for the prevention, control, and eradication of animal diseases, and is also responsible for the prevention of transmission of livestock diseases to humans. This dual mandate — protecting animals and people — is why the reporting net is cast so broadly across all parties who interact with livestock.

If you are a veterinarian working in Montana, your accreditation status does not exempt you from reporting; it actually increases your obligation. Cooperation with USDA/APHIS on eradication programs is conducted through the local Federal Area Veterinarian in Charge in Helena. Federally accredited veterinarians are expected to coordinate with both state and federal authorities when a reportable condition is identified. See how other states handle this same obligation in our guides to livestock disease reporting in Florida and livestock disease reporting in Colorado.

Signs and Symptoms That Trigger a Report in Montana

You do not need a confirmed laboratory diagnosis to be required to report. In Montana, a reasonable suspicion based on clinical signs is sufficient — and in many cases, legally required — to initiate contact with the Department of Livestock. Waiting for lab confirmation before reporting can cost critical days during a fast-moving outbreak.

The following clinical presentations should prompt an immediate report or consultation with the state veterinarian:

• Sudden, unexplained deaths — Especially when multiple animals in the same herd or pen are affected within a short period.
• Vesicular lesions — Blisters or erosions on the mouth, tongue, feet, or teats may indicate foot-and-mouth disease or vesicular stomatitis, both of which are foreign animal disease suspects.
• Severe respiratory distress — Rapid onset of labored breathing, nasal discharge, or coughing across multiple animals.
• Neurological signs — Circling, ataxia, seizures, or blindness in horses or cattle can indicate West Nile Virus, rabies, or other reportable encephalitic diseases. WNV is a viral infection that can cause encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord).
• Reproductive failure — Abortion storms, stillbirths, or infertility across multiple animals. When trichomoniasis is passed to cows, it can lead to repeat breeding, extended calving, early and occasional late-term abortion, and a high percentage of open cows at pregnancy check.
• Progressive wasting — Animals that lose body condition despite adequate feed, particularly in adult ruminants, may suggest Johne’s disease. Data shows how quickly Johne’s disease can spread through cattle sales and movement.
• High mortality in poultry — A sudden die-off in a poultry flock, especially combined with respiratory or neurological signs, is a red flag for highly pathogenic avian influenza or Newcastle disease. Learn more about Newcastle disease and other diseases in birds that may affect your flock.
• Unusual swellings or lameness — Swollen lymph nodes, joint effusions, or severe lameness in multiple animals warrant investigation.

For zoonotic diseases, the clinical picture extends to the people around the animals. While direct transmission of WNV between animals and people does not occur, a veterinarian’s diagnosis of WNV in an animal still warrants client education about zoonotic potential, since an infected mosquito is the route of transmission for both animals and humans, meaning a positive case in a horse or bird suggests the animal owner may have been exposed to the same infected mosquito population. Producers working with animals showing signs of zoonotic disease should also notify their personal healthcare provider.

How to Report a Livestock Disease in Montana

Montana channels disease reports through the Montana Department of Livestock’s Animal Health Bureau. Knowing the correct contact points and what information to have ready will make the process faster and more effective for everyone involved.

Step 1: Contact the Montana Department of Livestock Animal Health Bureau

The Department of Livestock Animal Health Bureau is located at PO Box 202001, Helena, MT 59620-2001, with an email contact of livpermits@mt.gov. For urgent disease reports, a phone call is always preferred over email. The bureau maintains staff available for disease emergencies outside normal business hours.

Step 2: Contact USDA APHIS Veterinary Services for Foreign Animal Disease Suspects

If you suspect a foreign animal disease — one that does not normally exist in the United States — you must also contact USDA APHIS Veterinary Services in addition to the state. USDA-APHIS Veterinary Services works to prevent, control, and/or eliminate animal diseases, and to monitor and promote animal health and productivity. The USDA APHIS emergency line operates 24 hours a day. For FAD suspects, do not move animals off the premises while awaiting investigation.

Step 3: Prepare the Information You Will Need to Report

Having the following details ready before you call will help the Animal Health Bureau respond more efficiently:

1. Your name, contact number, and physical address of the premises
2. Species affected and approximate number of sick versus total animals
3. Clinical signs observed and when they first appeared
4. Any recent animal movements onto or off the premises
5. Whether a veterinarian has already examined the animals
6. Any diagnostic test results already available
7. Vaccination history for the affected animals
8. Whether any humans on the premises are showing illness (for zoonotic disease suspects)

Step 4: Use the Montana Veterinary Diagnostic Laboratory (MVDL)

The Montana Veterinary Diagnostic Laboratory is the only accredited, full-service veterinary laboratory in Montana and provides disease diagnostic support to veterinarians, livestock producers, companion animal owners, and the Department of Fish, Wildlife and Parks, as well as other state and federal agencies. Submitting samples to the MVDL alongside your report accelerates confirmation and allows the state to begin tracing and response activities simultaneously. All data reported is from tests performed at the Montana Veterinary Diagnostic Laboratory (MVDL) and may include multiple tests for a single animal.

Producers in neighboring states can compare the process with guides for livestock disease reporting in California, livestock disease reporting in Illinois, and livestock disease reporting in Michigan to understand how Montana’s system compares regionally.

Reporting Deadlines and Timeframes in Montana

Montana’s reporting requirements are time-sensitive by design. The faster a disease report reaches state authorities, the faster containment measures can be put in place to protect your neighbors, your trading partners, and the broader Montana livestock economy.

Montana’s Administrative Rules establish tiered reporting timelines based on the severity and nature of the disease:

Changes in ownership must be reported to the Department within 30 days to maintain the registry’s integrity and support disease management efforts. While this applies specifically to ownership records, it underscores the general principle in Montana livestock law that timely notification is a non-negotiable component of disease management compliance.

For brucellosis specifically, Montana maintains a Designated Surveillance Area (DSA) around the Greater Yellowstone Area where bison and elk serve as wildlife reservoirs. Funding for Montana’s brucellosis program comes from Montana General Fund and cooperative agreement funding from USDA Veterinary Services. Producers in the DSA face additional ongoing testing and reporting timelines tied to the annual cattle production cycle. Test numbers follow the seasonality of the cattle production cycle and are useful in predicting program expenditures.

For alternative livestock operations with cervids, mandatory CWD surveillance requirements are codified under ARM 32.4.1302, with specific testing and reporting timelines tied to animal mortality events on licensed facilities.

What Happens After You Report in Montana

Filing a disease report sets a formal state response in motion. Understanding what to expect after you make that call helps you cooperate effectively and protects your operation throughout the process.

Initial Assessment and Investigation

Field operations include investigation of disease occurrence, import compliance, and enforcement of Montana Codes and Administrative Rules. After receiving your report, a DOL field veterinarian or animal health official will typically contact you to gather additional information and, in most cases, schedule an on-site investigation. For foreign animal disease suspects, this response is immediate and may involve both state and federal USDA APHIS personnel.

Quarantine and Movement Restrictions

If the investigation supports a diagnosis of a reportable disease, the DOL has authority to place the affected premises under quarantine. The department has quarantine authority; however, cases involving single animals or cases isolated to a private residence are not routinely quarantined. For herd-level diseases or those with significant spread potential, a quarantine order will restrict animal movement on and off the premises until the situation is resolved.

Laboratory Testing and Confirmation

Samples collected during the investigation are submitted to the MVDL or, for foreign animal disease suspects, to the USDA’s National Veterinary Services Laboratories (NVSL) in Ames, Iowa. Positive test results may not be confirmation of disease depending on the type of test conducted, so the DOL may require follow-up testing before issuing a formal disease status determination.

Tracing and Contact Notification

Once a disease is confirmed, the DOL initiates a trace-forward and trace-back investigation to identify animals that may have been exposed or that may have moved disease to other premises. In one documented Johne’s disease case in Montana, a single source operation sold cattle to 225 individual customers — 139 in-state and 86 out-of-state — with a total of 1,795 cattle sold over a four-year period. This illustrates why tracing is so critical: a single infected operation can seed disease across an entire region.

Control and Eradication Measures

The Disease Control Program functions to protect the Montana livestock industry from disease loss by providing for the diagnosis, prevention, and control of listed conditions. Depending on the disease, control measures may include depopulation of affected animals, mandatory testing of herd contacts, vaccination programs, or enhanced biosecurity requirements. Participating producers work with their local veterinarian to develop a herd health plan addressing biosecurity, herd testing, and management of high-risk animals, and then obtain a level of certification based on the health status of their herd and their testing plan.

Coordination with Public Health

For zoonotic diseases, the DOL coordinates with the Montana Department of Public Health and Human Services (DPHHS). Positive WNV cases are reported to the Department of Public Health and Human Services to support identification of positive mosquito pools within Montana and to help with messaging for WNV prevention in humans. This cross-agency coordination ensures that both animal and human health authorities are acting on the same information simultaneously.

Penalties for Failing to Report in Montana

Montana takes non-compliance with livestock disease reporting requirements seriously. The penalties for failing to report are designed both to punish non-compliance and to deter producers and veterinarians from delaying or avoiding their reporting obligations.

Civil and Criminal Penalties Under Montana Law

Under Montana Code Annotated (MCA) Title 81, violations of livestock disease control laws — including failure to report a known or suspected reportable disease — can result in both civil penalties and criminal charges. Willful violations may be prosecuted as misdemeanors, carrying fines and, in serious cases, potential imprisonment. The specific penalty amount is determined by the nature of the violation and whether it is a first or repeat offense.

Quarantine and Mandatory Testing Orders

Beyond direct financial penalties, failing to report can trigger involuntary quarantine orders and mandatory testing programs imposed on your entire operation. The Montana Department of Livestock enforces measures against contagious diseases, conducting inspections and monitoring compliance to prevent outbreaks. If a disease spreads because of a failure to report, the scope of the mandatory response — and its associated costs — falls largely on the non-reporting producer.

Loss of Market Access and Trade Privileges

A failure to report can also have significant indirect consequences. Montana’s livestock trading relationships depend on the state maintaining disease-free status for key conditions. Department reimbursement for testing has helped to minimize producer costs for program compliance while protecting the remainder of the state from unnecessary testing due to loss of Brucellosis class status or trading partner confidence. If non-reporting contributes to a loss of disease-free status, affected producers across the state — not just the one who failed to report — bear the economic consequences through restricted market access and reduced prices.

Penalties Specific to Zoonotic Disease Non-Reporting

For zoonotic diseases with direct public health implications, the consequences of non-reporting extend beyond livestock regulations. Failure to comply with management recommendations and to disclose a B. canis diagnosis will lead to a continued increase in positive cases, devastating disease in dogs, and potentially cases in humans. Regulatory authorities can pursue additional enforcement actions when non-reporting creates a demonstrable public health risk.

Veterinarian-Specific Consequences

Licensed veterinarians who fail to report face additional professional consequences beyond criminal or civil penalties. The Montana Board of Veterinary Medicine can pursue disciplinary action, including license suspension or revocation, for practitioners who knowingly fail to report a required condition. This professional accountability layer exists because veterinarians occupy a uniquely trusted position in the disease surveillance system.

Understanding the full scope of Montana’s livestock disease reporting requirements protects your operation, your neighbors, and the broader industry. The mission of the Montana Department of Livestock is to control and eradicate animal diseases, prevent the transmission of animal diseases to humans, and to protect the livestock industry from theft and predatory animals. Your timely report is a direct contribution to that mission. For more context on disease management across species, explore resources on Lyme disease in dogs and tick-borne disease prevention, as tick vectors that affect livestock can also affect companion animals on your property.