Bovine Tuberculosis Testing Requirements in Maine: A Cattle Owner’s Compliance Guide

Maine cattle owners rarely think about bovine tuberculosis testing requirements in Maine until a health certificate gets rejected at a sale barn or a routine slaughter inspection flags an unusual lesion. Bovine TB has not disappeared from the United States, and Maine’s herds remain part of a nationwide surveillance and testing system built around the disease’s slow, quiet spread. Understanding which animals need testing, which tests are approved, and what happens after a suspect result can save a producer weeks of quarantine headaches.

This guide walks through Maine’s classification status, testing methods, movement rules, and the penalties tied to skipping required tests. It draws on federal regulations from the USDA Animal and Plant Health Inspection Service (APHIS) and Maine’s Department of Agriculture, Conservation and Forestry (DACF), so you can see exactly where state practice lines up with federal law.

What Is Bovine Tuberculosis and Why It Is Regulated in Maine

Mycobacterium bovis, the bacterium behind bovine tuberculosis, causes a chronic and sometimes fatal respiratory disease in cattle, bison, and a wide range of other mammals, including humans. According to APHIS, bovine tuberculosis is a contagious, infectious, communicable disease of animals and humans caused by Mycobacterium bovis, and it is commonly a chronic, debilitating disease but occasionally may assume an acute, rapidly progressive course. The bacteria travel through the air and through contaminated feed, which is why a single infected animal can put an entire herd at risk before anyone notices clinical signs.

Disease is spread by direct contact, inhalation of droplets expelled from infected lungs, and ingestion of contaminated feed or milk. That transmission pattern is exactly why regulators focus on herd-level testing rather than waiting for sick animals to show symptoms, since APHIS notes that if cattle or bison show clinical signs of tuberculosis, the disease has advanced to affect multiple organ systems, which is rare.

Maine has an added wrinkle that most states do not: widespread raw milk sales. The University of Maine Cooperative Extension points out that Maine allows the sale of both pasteurized and unpasteurized, raw, milk products, which means there is an elevated risk of M. bovis being spread to the public if it was ever reintroduced into dairy herds. That risk is a major reason Maine maintains its own standard operating procedure for handling non-negative screening tests in dairy herds, on top of the federal framework. For a broader look at how bovine disease surveillance works across species, see this overview of bovine disease management. Bovine TB is also a distinct condition from avian tuberculosis, which affects poultry and wild birds through a related but separate strain of Mycobacterium.

Maine’s TB Classification Status and Risk Zones

Every state carries a USDA tuberculosis classification that determines how strict its testing and movement rules are. As of April 2022, researchers writing in a peer-reviewed review noted that with the exception of four counties in Michigan comprising only 6,109 square kilometers, which were classified as Modified Accredited, the entire country was considered Accredited Free of bTB by the USDA for cattle and bison. Maine falls into that Accredited Free category, the highest tier a state can hold.

Accredited Free status is not permanent. Under federal rule, accredited-free State or zone status must be renewed annually, and a state can lose that status quickly if disease turns up. If two or more affected herds are detected in an accredited-free State or zone within a 48-month period, the State or zone will be removed from the list of accredited-free States or zones and will be reclassified as modified accredited advanced. Even a single detected herd carries risk, though the rule gives some room to recover: if an affected herd is detected in a State or zone classified as accredited-free, and the herd is depopulated and an epidemiologic investigation is completed within 90 days of the detection of the affected herd with no evidence of the spread of tuberculosis, the State or zone may retain its accredited-free status.

Classification Tier	Testing Burden	Applies to Maine
Accredited Free	Lowest — routine slaughter surveillance, movement testing mainly for interstate shipments	Yes, current status
Modified Accredited Advanced	Moderate — added whole-herd and pre-movement testing	No
Modified Accredited	Higher — more frequent herd testing, tighter movement conditions	No
Accreditation Preparatory	Highest — annual whole-herd testing plus additional pre-movement tests	No

The one persistent risk zone in the country sits in northern Michigan, where white-tailed deer act as a wildlife reservoir for the bacteria. As the same review explains, the now well-described circumstances of endemic bTB in Michigan, where white-tailed deer serve as a free-ranging wildlife maintenance host, may appear to be the principal remaining barrier to national eradication. Maine has no known wildlife reservoir for bovine TB, though the state’s wildlife agencies still monitor deer populations as a precaution — a topic connected to broader wildlife management discussed in this guide to Maine hunting license requirements.

Pro Tip: Ask your veterinarian or the Maine DACF Division of Animal and Plant Health to confirm the state’s current classification before planning a multi-state cattle purchase. Classification status can shift if a herd tests positive anywhere in the state.

Who Must Test and Which Animals Are Covered in Maine

Not every animal on a Maine farm needs a caudal-fold test every year. Federal rule sets minimum testing eligibility by classification tier, and in Accredited Free states like Maine, most herds are exempt from routine whole-herd testing unless there’s a specific trigger — an incoming animal from a higher-risk state, a suspect lesion found at slaughter, or participation in an interstate sale that requires proof of negative status.

Cattle and bison are the primary regulated species under the federal program. The Uniform Methods and Rules define several categories that determine testing obligations, including “exposed cattle and bison,” described as cattle and bison, except reactor cattle and bison, that are part of an affected herd. Captive cervids — deer, elk, and moose kept for meat, sport, or exhibition — fall under the same federal umbrella and carry their own testing schedule, since captive cervid means all species of deer, elk, moose, and all other members of the family Cervidae raised or maintained in captivity for the production of meat and other agricultural products, for sport, or for exhibition.

Testing responsibility typically falls on:

• Herd owners bringing new cattle or bison onto their premises from another state
• Dairy and beef producers selling breeding stock across state lines
• Exhibitors moving cattle or captive cervids to fairs, shows, or sale barns
• Farms designated for follow-up testing after a suspect screening result
• Accredited veterinarians, who are required to report findings promptly

APHIS is direct about that reporting duty: all accredited veterinarians must immediately report every suspected or diagnosed bovine TB case promptly to both the Assistant District Director and the State Animal Health Official. That reporting chain applies in Maine exactly as it does everywhere else in the country, and it’s one reason producers should always use an accredited vet for any herd health work, not just for TB testing.

Approved TB Testing Methods in Maine

Maine follows the same federally approved testing menu used nationwide — there’s no separate state-specific test. According to South Dakota’s Animal Industry Board, which mirrors the national Uniform Methods and Rules that Maine also follows, there are three official TB tests for cattle and bison: CFT, CT, and CCT, and the Interferon Gamma Assay – Bovigam is an official test for cattle only, with no other tests official or approved.

The caudal-fold test (CFT) is the standard screening tool a Maine accredited veterinarian will reach for first. It works by injecting tuberculin and watching for a reaction:

1. Injection — The vet gives an intradermal injection of USDA-licensed PPD bovis tuberculin, since only bovine purified protein derivative tuberculin (PPD bovis) licensed by USDA for official testing may be used.
2. Observation window — If an animal is exposed to the antigens present in bovine TB, a tuberculin injection results in a delayed hypersensitivity reaction manifested by swelling and induration at the injection site, with a positive response usually beginning within 8 to 12 hours and peaking about 72 hours after injection.
3. Physical check — Test observation without palpation is unacceptable; the vet must physically feel the injection site, not just look at it.
4. Recording — Results go on the official VS Form 6-22, where the vet will enter “N” for negative when observing no change in the tissue, or “S” for suspect when observing or palpating any increase in caudal fold thickness, size, or sensitivity.
5. Follow-up — Any suspect or reactor result triggers a comparative cervical test, gamma interferon assay, or direct referral to slaughter under permit, since the caudal-fold test is used as a presumptive diagnostic procedure, and animals classified as suspect must be evaluated further by the comparative cervical test, gamma interferon test, or sent directly to slaughter under permit.

Because the test relies on the animal’s own immune response, timing matters. APHIS warns that the animal being tested should not concurrently be receiving other medications, vaccinations, or anthelminthic drugs, because these agents may temporarily affect the immune system and influence the result of the tuberculin test. Sick animals are excluded from testing for the same reason, since sick animals may not be injected even if they are not being medicated or treated in any fashion.

Maine’s State and Federal Diagnostics Laboratory handles the paperwork side of testing. The lab provides proficient and accurate surveillance and diagnostic testing to maintain high quality, disease free livestock and poultry industries, performing serological testing on all species of livestock for brucellosis monitoring, interstate and international exportation requirements, diagnostic purposes and breeding purposes. Producers or veterinarians can reach the lab directly, and records — including the state’s Tuberculosis Test Record form — must be filed with each official test.

Key Insight: Only accredited or regulatory veterinarians may perform official TB tests, and per federal guidance, veterinarians are legally responsible for properly conducting and evaluating the results of tuberculin tests, so they should perform the test themselves rather than delegate it to a technician.

Interstate and Intrastate Movement Testing Requirements in Maine

Most Maine producers encounter TB testing rules for the first time when they try to buy or sell cattle across state lines. A federal permit and health paperwork system governs that movement, and Maine layers its own import permit requirement on top.

Under federal rule, cattle originating from states with a lower classification than Accredited Free face extra conditions before they can cross into Maine. For animals coming from a modified accredited advanced state or zone, one accepted path requires that the cattle or bison are from an accredited herd, are officially identified, and are accompanied by an ICVI stating that the accredited herd completed the testing necessary for accredited status with negative results within 1 year prior to the date of movement. Animals from an accreditation preparatory state face a stricter timeline, needing proof that the herd from which they originated was negative to a whole herd test conducted within 1 year prior to the date of movement and that the individual animals to be moved were negative to an additional official tuberculin test conducted within 60 days prior to the date of movement.

On the Maine side, DACF requires paperwork regardless of the origin state’s classification. The state’s import rules confirm that a permit is required for all cattle imported into the state, with a narrow exception: this permit rule does not apply to cattle imported from Canada consigned to a slaughter establishment. Beyond the permit, Maine’s import office flags that additional documentation is often necessary — the state advises producers to consult Chapter 206 or InterstateLivestock.com or call Animal Health to determine if additional paperwork, such as a Certificate of Veterinary Inspection, USDA VS 9-3 form, NPIP certification, or additional health tests or vaccines, are required to import animals to Maine.

A few practical notes for anyone moving cattle in or out of Maine:

• Cattle, goats, sheep, and swine all require official USDA approved ID when imported.
• Import permit requests tied to weekend transport, such as fair season, generally need to be submitted several business days ahead — check current DACF guidance before travel.
• Federal law bars interstate movement of animals actively affected with TB except under specific permit conditions, since animals or poultry affected with tuberculosis shall not be moved to another State except as provided for in the CFR.
• Maine’s own Livestock Importation page lists categories of animals that do not require an import permit — always verify your specific class of animal before assuming an exemption applies.

Intrastate movement — cattle sold or transported within Maine — carries lighter testing requirements since the whole state shares Accredited Free status, but official identification and standard herd health documentation are still expected at sale barns and fairs.

What Happens When a Suspect or Positive Result Occurs in Maine

A “suspect” result on a caudal-fold test does not mean an animal has tuberculosis — it means the injection site reacted enough to warrant a closer look. Maine’s standard operating procedure was written specifically to manage this gray area given the state’s raw milk sales, and the University of Maine Cooperative Extension notes that it is necessary to create a scientifically based standard operating procedure for animals that are found to be suspect animals on screening TB tests because of the elevated public health stakes.

Once a test produces any response, the clock starts immediately. Federal guidance is unambiguous: if the test produces any type of response, immediately notify your APHIS-VS Area Offices and State animal health officials. From there, only specially trained personnel can move the case forward, since only Federal or State regulatory veterinarians who have had specialized training may conduct the follow up testing.

Follow-up testing runs on a strict schedule. The comparative cervical test must happen quickly or not at all for a while: follow-up CCT testing must be performed within 10 days of the initial caudal-fold injection in cattle and bison, or the herd owner must wait 60 days after the injection of the CFT before a follow-up CCT can be attempted. This gap exists because tuberculin itself can temporarily desensitize the animal’s immune response, making an early retest unreliable.

If a reactor is confirmed, movement restrictions kick in immediately. Federal rule requires that reactors shall remain on the premises where they were disclosed until a State or Federal permit for movement has been obtained, and movement for immediate slaughter shall be within 15 days of classification and shall be directly to a slaughtering establishment where approved State or Federal inspection is maintained. Reactors are also physically marked so no one down the supply chain mistakes them for a healthy animal: reactor cattle and bison shall be identified by branding the letter “T” on the left hip near the tailhead, not less than 2 inches and not more than 3 inches high, and by tagging with an approved metal eartag bearing a serial number and inscription “U.S. Reactor” or a similar State reactor tag.

Important Note: Milk from a reactor animal cannot enter the food supply. Industry testing guidance confirms that milk from TB reactors must not be used for human or animal consumption, and owners of reactors must be advised to segregate tuberculin reactors from non-reactors and dispose of their milk in a safe manner. Given Maine’s active raw milk market, this step is treated as a top compliance priority by state investigators.

Quarantine and Herd Depopulation Rules in Maine

When a herd is confirmed affected — meaning at least one animal has tested positive for M. bovis — Maine works within the same federal quarantine framework used across the country. The definition of quarantine under federal rule is straightforward: it means prohibition from interstate movement, except for slaughter or necropsy. In practice, that means no animal leaves the affected premises for any purpose other than direct shipment to an approved slaughter facility under permit.

Whole-herd depopulation is the standard response to a confirmed affected herd, and it’s the fastest route back to good standing for the state. As noted earlier, Maine’s Accredited Free status can survive a single detection if officials move quickly: an affected herd must be depopulated and an epidemiologic investigation completed within 90 days of the detection of the affected herd with no evidence of the spread of tuberculosis for the state to keep its top classification. That 90-day window puts real pressure on state and federal officials to coordinate depopulation, indemnity payments, and epidemiological tracing simultaneously.

If a farm restocks a depopulated premises with other livestock species, those animals don’t get a free pass. Federal rule extends the same herd test requirements to any newly assembled herd on the site: if any livestock other than cattle or bison are included in a newly assembled herd on a premises where a tuberculous herd has been depopulated, the State or zone must apply the herd test requirements contained in the Uniform Methods and Rules to those other livestock in the same manner as to cattle and bison.

Investigators also look outward from the affected farm, not just at the herd itself. National surveillance planning documents describe this as tracing how the herd became infected in the first place, since herds are usually affected in one of two ways: purchasing infected animals or being exposed to infected wildlife. Wildlife surveillance around any Maine detection would follow the same national playbook used elsewhere, and APHIS maintains wildlife TB surveillance guidelines for exactly this scenario, even though Maine currently has no known wildlife reservoir.

Penalties for Non-Compliance in Maine

Skipping required testing, moving cattle without proper certificates, or falsifying import paperwork carries consequences beyond a rejected sale-barn entry. Veterinarians who fail to follow reporting protocol risk their federal accreditation, since testing guidance states plainly that all tuberculin tests conducted for any purpose on cattle and bison are official tests and must be reported to the cooperative State-Federal program officials, and failure to report a tuberculin test is sufficient grounds for the removal of an accredited veterinarian status.

For producers, the practical penalty often comes through blocked movement rather than a courtroom fine. An animal without proper TB documentation simply cannot legally cross state lines, be sold through a regulated sale barn, or enter a fair or exhibition. Maine’s import office is explicit that permits and paperwork are a prerequisite, not a formality, warning producers to confirm requirements by consulting Chapter 206, InterstateLivestock.com, or calling Animal Health directly to determine if additional paperwork or health tests are required before transport.

Maine’s broader animal health enforcement structure mirrors how the state handles other regulated disease and licensing programs — the same compliance logic that governs rabies vaccination requirements for cats or leash law enforcement applies to livestock health documentation: missing paperwork creates liability, delays, and in some cases civil penalties under Maine’s animal disease statutes. Producers who import cattle for exhibition, 4-H programs, or breeding stock without confirming species-specific health requirements ahead of time are the ones most likely to face last-minute rejections at a fairground gate.

Pro Tip: Keep copies of every ICVI, import permit, and TB test record for at least two years. Federal rule requires states to retain movement certificates for a similar period, and having your own paper trail speeds up any compliance review considerably.

Bovine tuberculosis testing requirements in Maine ultimately protect a status the state has held for years: freedom from a disease that once infected a meaningful share of American cattle. Staying compliant is less about avoiding fines and more about keeping that status intact for every producer in the state, since one lapsed herd can trigger downgrades and testing burdens for everyone. Work with an accredited veterinarian, confirm import paperwork before any cattle cross state lines, and treat suspect results as the urgent matter federal and state officials already do.