Bovine Tuberculosis Testing Requirements in South Dakota: Rules Every Cattle Producer Should Know
August 31, 2026
South Dakota has held USDA Accredited Free status for bovine tuberculosis since 1982, yet the disease has turned up in the state’s cattle herds several times in the last decade. That gap between an official disease-free label and real-world outbreaks is exactly why bovine tuberculosis testing requirements in South Dakota exist, and why every cattle owner, hauler, and buyer in the state needs to understand them before an animal ever crosses a fence line.
You’ll find the rules scattered across federal regulations, state administrative code, and Animal Industry Board policy, which makes them easy to misread or miss entirely. This guide walks through what triggers testing, which animals are covered, which tests count as official, and what happens to your herd if a result comes back anything other than clean.
What Is Bovine Tuberculosis and Why It Is Regulated in South Dakota
Bovine tuberculosis is caused by Mycobacterium bovis, a bacterium that produces a chronic, slowly progressive disease in cattle and can infect people and wildlife under the right conditions. According to the USDA Animal and Plant Health Inspection Service, 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. Disease is spread by direct contact, inhalation of droplets expelled from infected lungs, and ingestion of contaminated feed or milk.
Regulators treat the disease seriously not because it threatens the food supply directly, but because of how easily it can move through cattle populations before anyone notices. State veterinarian statements from recent South Dakota outbreaks note that bovine TB is not currently a threat to food safety in the U.S. due to milk pasteurization and comprehensive meat inspection programs. Cattle themselves rarely show it: cattle rarely exhibit visible signs of illness, which is why testing of cattle herds is necessary to determine if animals are infected.
Pro Tip: Because infected cattle often look completely healthy, don’t rely on visual inspection alone before purchasing or moving animals. Ask for testing records and a current Certificate of Veterinary Inspection every time.
Producers who also run other livestock disease programs will recognize the pattern from other livestock biosecurity requirements in South Dakota — testing and traceability are the front line because clinical signs show up too late to prevent spread.
South Dakota’s TB Classification Status and Risk Zones
South Dakota’s federal disease status sets the baseline for every testing requirement that follows. South Dakota has officially been recognized as free of the disease since 1982, according to the South Dakota Animal Industry Board. Under 9 CFR Part 77, South Dakota is currently listed among the states classified for TB purposes, and an accredited-free designation requires zero percent prevalence of affected captive cervid herds, and no findings of tuberculosis in any captive cervid herds in the State or zone for the previous 5 years. That status is not permanent or automatic. To qualify for renewal of accredited-free State or zone status, a State must submit an annual report to APHIS certifying that the State or zone within the State complies with the provisions of the “Uniform Methods and Rules—Bovine Tuberculosis Eradication.”
Despite that status, the disease has resurfaced repeatedly. Bovine TB has been reconfirmed in cattle herds located in Harding, Hutchinson, Tripp and Yankton counties over recent years, according to South Dakota Game, Fish and Parks. As recently as January 2025, the state veterinarian confirmed bovine tuberculosis in a cow herd in Kingsbury County, with the infected herd identified through traceback efforts on a Hamlin County feedlot steer. Nationally, the disease is genuinely rare: fewer than 12 cases of bovine TB were discovered through meat inspection in each year from 2019 through the third quarter of fiscal year 2024, and the USDA estimates prevalence in cattle, bison, and captive cervids at approximately 7 per 1 million cattle screened.
These outbreak counties also function as informal risk zones for wildlife surveillance. Game, Fish and Parks has worked alongside the Animal Industry Board to test numerous deer, pronghorn, coyotes and other small mammals adjacent to these cattle outbreaks, and so far bovine TB has not been found in deer or other wildlife species in South Dakota. Anyone with hunting license requirements in South Dakota to review before a fall season near an affected county should also know that field-dressing precautions matter: hunters should wear rubber gloves when field dressing wild game, and cooking meat to an internal temperature of at least 165 degrees Fahrenheit will destroy the bacteria.
| Status | Definition | South Dakota Relevance |
|---|---|---|
| Accredited-Free | Zero prevalence in affected herds; no confirmed cases in captive cervids for 5 years | South Dakota’s designation since 1982 |
| Modified Accredited | Higher allowable prevalence threshold under 9 CFR Part 77 | Listed as a fallback category under federal rule |
| Outbreak/Risk County | County with a confirmed herd or feedlot case requiring trace-out testing | Harding, Hutchinson, Tripp, Yankton, Kingsbury (historical) |
Who Must Test and Which Animals Are Covered in South Dakota
Testing obligations depend on what kind of animal you own, where it’s going, and whether your herd already carries accredited status. An accredited herd is defined by South Dakota rule as one that has undergone tuberculosis tests of all eligible animals conducted at nine to fifteen-month intervals and has no evidence of bovine tuberculosis or exposure to it.
In practice, testing obligations typically apply to:
- Cattle and bison over one month of age moving into South Dakota from another state or Canada
- Animals added to herds that were previously depopulated due to TB
- Cattle in herds under an active traceback or epidemiological investigation
- Recreational and exhibition cattle subject to annual testing rules
- Captive cervid herds seeking qualified or accredited herd status
Newly restocked herds face an especially structured schedule after a depopulation event. Under South Dakota administrative rule, in a newly assembled herd on a premises where a tuberculous herd has been depopulated, two annual herd tests may be applied at the discretion of the state veterinarian, with the first test applied approximately six months after assembly, followed by two complete herd tests at three-year intervals.
Beef steers destined for immediate slaughter occupy a notable gray area. Multiple South Dakota TB investigations have been complicated by the fact that beef steers are not required to have official identification, so no official ID was collected at slaughter — a gap that has repeatedly slowed traceback efforts after a positive slaughter finding. If you’re running a mixed operation, pairing TB compliance with other livestock biosecurity requirements in South Dakota and consistent identification practices closes that gap voluntarily.
Approved TB Testing Methods in South Dakota
South Dakota recognizes a limited set of official tests, and using anything outside that list won’t satisfy import or herd-certification requirements. According to Animal Industry Board testing guidance, there are three official TB tests for cattle and bison — CFT, CT, and CCT — and the Interferon Gamma Assay (Bovigam) is an additional official test for cattle only.
| Test | Method | Typical Use |
|---|---|---|
| Caudal Fold Test (CFT) | Intradermal tuberculin injection in the tail fold; read for swelling | Routine screening and import testing |
| Comparative Cervical Test (CCT) | Two tuberculin injections in the neck, compared at 72 hours | Follow-up on suspect CFT results |
| Caudal Fold Test Retest (CT) | Repeat caudal fold procedure | Herd-level confirmation testing |
| Interferon Gamma Assay (Bovigam) | Blood-based laboratory assay | Cattle only, supplemental diagnosis |
The caudal fold test remains the workhorse of routine screening. Per federal guidance, test observation without palpation is unacceptable, and results are recorded on VS Form 6-22, with a reading of “N” for negative when no change is observed at the injection site, or “S” for suspect when any increase in caudal fold thickness, size, or sensitivity is observed or palpated. Timing matters for accuracy: a positive response usually begins within 8 to 12 hours and peaks about 72 hours after injection. The comparative cervical test uses an intradermal injection of biologically prepared tuberculins into two separate sites in the midcervical area, comparing the response of the two tuberculins 72 hours plus or minus 6 hours following injection.
Key Insight: A positive caudal fold test does not automatically mean an animal has bovine TB. Cross-reactions from Johne’s disease, avian TB, and even soil bacteria can trigger a false response in roughly 1 to 5 percent of tested cattle, according to California Department of Food and Agriculture testing guidance. That’s why suspect results always trigger a confirmatory test rather than an immediate quarantine action.
Only a licensed, USDA-accredited veterinarian can perform official testing, and the same person who administers the injection must read the result. If you also handle equine movement, the parallel is worth noting: much like EIA Coggins test requirements in South Dakota, TB testing has to be performed by an accredited veterinarian and documented on an official form before it counts for movement or sale purposes.
Interstate and Intrastate Movement Testing Requirements in South Dakota
Moving cattle into South Dakota triggers its own layer of testing rules, separate from herd-level accreditation. For animals entering from another U.S. state, Animal Industry Board policy requires a tuberculosis test conducted by a United States accredited veterinarian within 30 days prior to importation into South Dakota, with individual official identification listed on the health certificate.
Cattle and bison arriving from Canada face a longer testing window but the same underlying logic: a negative TB test within 60 days is required for all cattle and bison over one month of age, except cattle and bison designated for immediate slaughter or quarantined to a feedlot until sold to slaughter.
Cattle and bison that originate in an accredited-free state, like South Dakota’s own herds moving to other accredited-free states, generally move with fewer hurdles. Federal rule confirms that cattle or bison that originate in an accredited-free State or zone may be moved interstate in accordance with 9 CFR Part 86 without further restriction under this part. Every animal still needs a Certificate of Veterinary Inspection, and Animal Industry Board policy accepts several electronic CVI platforms for both imports and exports, including VSPS, Sale Time, and GlobalVetLink.
State law backs these requirements with real legal weight. Under South Dakota codified law, any animal brought into the state for any purpose except immediate slaughter must be accompanied by a certificate of veterinary inspection verifying it is free from signs of disease and does not originate from a quarantine area, inspected within 30 days before arrival. If you’re hauling animals across county or state lines, make sure your livestock trailer requirements in South Dakota paperwork and your CVI travel together, and confirm brand inspection requirements in South Dakota apply to your load before you leave the yard.
What Happens When a Suspect or Positive Result Occurs in South Dakota
A suspect result doesn’t end at the chute. Federal protocol requires escalation: 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. Animal Industry Board guidance narrows the CCT timeline further, calling for a suspect Comparative Cervical Test retest in 60 days or sending the suspect animal to slaughter with tissues submitted for evaluation.
Reporting is not optional for the testing veterinarian. Federal guidance is direct: 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. Any reaction to the test itself also triggers notification: if the test produces any type of response, the veterinarian must immediately notify APHIS Veterinary Services Area Offices and state animal health officials.
Real cases show how fast this moves once a slaughter-line finding comes in. In the most recent confirmed South Dakota case, USDA’s National Veterinary Services Laboratories in Ames, Iowa, confirmed samples were positive for TB on Nov. 5, and the culture isolate was reported Dec. 6 to be Mycobacterium bovis. From there, records from the packing plant linked the animal to a feedlot in Hamlin County, and the state veterinarian traced the steer back to a Kingsbury County herd using state records. An earlier, larger investigation in Harding County followed the same pattern at greater scale: official identification and market records were used to identify the herd of origin in Harding County, which was tested by state and federal animal health officials, revealing 38 additional infected animals.
Quarantine and Herd Depopulation Rules in South Dakota
Once a reactor is confirmed, quarantine follows automatically and without exception. Under the federal Uniform Methods and Rules that South Dakota administers, all herds in which reactor animals are disclosed shall be quarantined immediately, and exposed animals must remain on the premises where disclosed unless a state or federal permit for movement has been obtained. A quarantined herd stays that way until all requirements of an individual herd plan have been completed, unless the owner elects depopulation instead.
Getting a quarantine lifted without depopulation requires a demanding, multi-year testing sequence. The required protocol calls for:
- Two consecutive whole-herd tests where every responder to a primary test (CT or CFT) is examined postmortem with no evidence of infection
- Six consecutive herd tests where CFT responders are cleared by supplemental testing (CCT or interferon gamma) and/or postmortem review
- At least 60 days between each of the first four herd tests
- At least 180 days between later tests in the sequence
- Two additional clean annual tests after quarantine release
This structure comes directly from federal rule: the herd testing requirement shall consist of at least two consecutive tests with all responders examined postmortem, followed by six consecutive tests with responders classified negative to supplemental testing, with testing intervals of at least 60 days between the first four herd tests and at least 180 days between later tests.
Depopulation is faster but far more disruptive, and it remains the path most South Dakota outbreaks have actually followed. In the 2025 Kingsbury County case, officials worked with the USDA and the herd owner to depopulate the herd after multiple cows tested positive. In the 2017 Harding County outbreak, the index ranch of roughly 650 head was depopulated, and the Tripp County index herd of approximately 340 head, linked through official animal identification records, was also depopulated after laboratory confirmation revealed 39 additional infected animals.
Important Note: Feedlots face a related but distinct process. Federal rule specifies that cattle known to be exposed in a feedlot setting must be quarantined and shipped under permit directly to slaughter, and the affected pens must be vacated, cleaned, and disinfected before restocking can begin.
Owners who depopulate may qualify for federal indemnity, though eligibility comes with strings attached. Federal regulation notes that to be eligible for federal indemnity, other exposed livestock must be identified by tagging with a serially numbered metal eartag, and all such animals must be transported under permit in vehicles closed with official seals or accompanied by a federal or state representative. Indemnity claims can also be denied outright if there is substantial evidence that the owner or the owner’s agent has in any way been responsible for any attempt to obtain indemnity funds unlawfully or improperly.
Penalties for Non-Compliance in South Dakota
South Dakota backs its import and testing rules with criminal penalties, not just civil paperwork consequences. Bringing an animal into the state without a valid Certificate of Veterinary Inspection is treated seriously: any person who brings animals into the state in violation of that certification requirement is guilty of a Class 6 felony. That’s the same tier of consequence attached to several other unauthorized-import scenarios under South Dakota livestock law.
Lesser violations still carry real teeth. If an animal does arrive without proper certification, state law provides that it shall be detained at its destination or another suitable place under quarantine until it has been examined by the Animal Industry Board and a certificate of veterinary inspection issued, and releasing that animal from quarantine before inspection is itself a chargeable offense. South Dakota code separately makes it a misdemeanor to remove or release animals shipped under false billing, and a misdemeanor for a veterinarian to certify an animal without actually inspecting it.
Common Mistake: Producers sometimes assume a permit obtained in place of a CVI removes all further obligations. It doesn’t — animals brought in under a notice-and-permit arrangement instead of a CVI are still subject to Animal Industry Board inspection and can still be quarantined if the board has reason to suspect exposure.
Beyond statutory penalties, non-compliance carries indirect financial costs that often outweigh the fines themselves. A herd found in violation of an approved plan risks losing eligibility for federal indemnity, extended quarantine timelines, and the reputational cost of a documented outbreak on a public traceback record. Producers who keep rabies vaccine requirements in South Dakota and other mandatory animal health obligations current tend to build the same clean documentation habits that make TB compliance far less painful when a routine slaughter check flags a traceback.
Bovine tuberculosis testing requirements in South Dakota exist because eradication is never truly finished — it’s maintained, year after year, through consistent testing, honest documentation, and fast reporting when something looks wrong. Whether you’re importing a single bull or managing a multi-generation cow-calf operation, the safest approach is the same: work with an accredited veterinarian, keep your CVI and identification records current, and contact the South Dakota Animal Industry Board directly whenever a movement or herd situation falls outside the routine.