Bovine Tuberculosis Testing Requirements in Arizona: What Cattle and Bison Owners Must Know

Arizona has carried an accredited-free bovine tuberculosis classification for decades, but that status does not eliminate the paperwork, testing windows, and movement rules that apply to cattle and bison owners across the state. Bovine tuberculosis testing requirements in Arizona still govern how animals enter the state, how herds get monitored, and what happens the moment a test comes back suspect. A single positive result in a Pinal County rodeo herd was enough to trigger a quarantine, which is a reminder that “accredited-free” is a status you maintain, not one you can ignore.

This breakdown covers what the disease is, how Arizona classifies its risk, which animals and owners fall under testing rules, the specific tests regulators accept, and what happens when a herd tests positive.

What Is Bovine Tuberculosis and Why It Is Regulated in Arizona

Mycobacterium bovis is the bacterium behind bovine tuberculosis, and it does not stay confined to cattle. According to the USDA Animal and Plant Health Inspection Service (APHIS), bovine tuberculosis (TB) is a contagious, infectious, communicable disease of animals and humans caused by Mycobacterium bovis. The disease spreads efficiently between herdmates and can cross into people as well: disease is spread by direct contact, inhalation of droplets expelled from infected lungs, and ingestion of contaminated feed or milk.

APHIS also notes that bovine tuberculosis is a rare disease that affects mammals, including cattle, deer, goats, dogs, and humans. There is no cure once an animal is infected, which is exactly why testing carries so much weight in state regulation. As APHIS puts it, tuberculosis is not treated in livestock, so prevention and early detection are the only real tools available to producers and regulators alike.

The regulatory framework tracing back to this reality is not new. In 1917, the U.S. Bureau of Animal Industry began the National Tuberculosis Eradication Program due to human and livestock concerns regarding bovine tuberculosis. That program, now run jointly by APHIS and state veterinary offices, is the backbone of every testing rule Arizona enforces today. For a broader look at how this illness compares to other livestock health threats, see this overview of common bovine disease in cattle herds.

Arizona’s TB Classification Status and Risk Zones

Arizona’s testing burden is lighter than in states with active infection, largely because of its federal classification. Under 9 CFR Part 77, the following are accredited-free States: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, among others. To keep that designation, a state has to meet a strict definition: an accredited-free State or zone is a State or zone that is or is part of a State that has the authority to enforce and complies with the provisions of the “Uniform Methods and Rules—Bovine Tuberculosis Eradication,” has zero percent prevalence of affected captive cervid herds, and has had no findings of tuberculosis in any captive cervid herds in the State or zone for the previous 5 years.

Arizona does not carry any internal risk zones with weaker status, either. The federal regulation is explicit that the following are modified accredited zones: None for Arizona. Compare that to the bottom tier of the classification system, where a nonaccredited State or zone is one that does not meet the standards of the Uniform Methods and Rules or in which tuberculosis is prevalent in 0.5 percent or more of the total number of herds of cattle and bison in the State or zone.

Classification	What It Means	Testing Burden
Accredited-Free (Arizona’s status)	Zero percent herd prevalence for at least five years	Lowest; testing mainly tied to imports
Modified Accredited	Some documented cases but under active control	Higher; whole-herd testing intervals apply
Nonaccredited	0.5% or more herd prevalence, or noncompliant program	Highest; strict import and movement testing

Arizona has earned this status the hard way. Arizona has been declared free of bovine tuberculosis since 1978, and though that free status was temporarily suspended due to an incident in 1979, it was reinstated in 1981 after prompt elimination of the disease. More recently, a 2023 case tested that record: the Arizona Department of Agriculture announced a single steer in a Pinal County rodeo stock operation tested positive for bovine tuberculosis, and the event cattle operation was placed under quarantine. Notably, the affected steer had recently been imported into Arizona from Mexico and tested negative for bovine TB at the time of importation, showing how a single animal can still slip through routine screening.

Who Must Test and Which Animals Are Covered in Arizona

Testing obligations in Arizona fall into two broad buckets: whole-herd surveillance for animals already in the state, and entry testing for animals coming in. The federal whole herd test standard defines the covered population as an official tuberculin test of all cattle and bison in a herd that are 12 months of age or older, and of all cattle and bison in the herd that are less than 12 months of age and were not born into the herd, except those cattle and bison that are less than 12 months of age and were born in and originated from an accredited herd. Where whole-herd testing is required for accreditation renewal, the tests must be conducted at 9-15 month intervals.

For animals crossing into Arizona, the rules vary by category:

• General livestock imports: all livestock require an original health certificate issued by a veterinarian within 30 days prior to importation and an import permit, except horses.
• Rodeo and exhibition cattle: tuberculosis testing is not required unless the state of origin’s status is less than Accredited Free.
• Beef breeding cattle, breeding bison, and dairy cattle: covered by dedicated rules under tuberculosis testing requirements for beef breeding cattle, breeding bison, and dairy cattle imported into Arizona from other states.
• Cattle and bison from Mexico: subject to a separate set of tuberculosis testing requirements for cattle and bison imported into Arizona from Mexico.

Owners who also haul stock across state lines should check current requirements for livestock trailer requirements in Arizona, since transport documentation and TB paperwork are often reviewed together at inspection points. Rabies control is handled separately in Arizona, but producers managing multiple animal health obligations may also want to review rabies vaccine requirements in Arizona for a fuller compliance picture.

Pro Tip: Confirm testing status before you buy. Native ranch cattle moved directly from an accredited herd, with the accreditation number documented on the health certificate, are exempt from a fresh TB test at the Arizona border.

Approved TB Testing Methods in Arizona

Arizona follows the federally standardized testing sequence used nationwide, starting with a screening test and escalating only when results warrant it. The first-line test is the caudal fold test: a small amount of purified protein derivative (PPD) tuberculin is injected into the fold of skin at the base of the tail, and the CFT is read 72 plus or minus 6 hours later. Regulators require a specific product for this step, since official testing must use only bovine purified protein derivative tuberculin (PPD bovis) licensed by USDA.

Results are not perfect. A false positive rate of 1-2% is expected during a whole herd test, which is why a single reaction does not automatically mean infection. APHIS describes the caudal fold test’s role plainly: 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.

Test	Method	Timing
Caudal Fold Test (CFT)	Tuberculin injected at base of tail	Read 72 ± 6 hours after injection
Comparative Cervical Test (CCT)	Two neck injections, bovine and avian tuberculin	Within 10 days or after 60 days of the CFT
Gamma Interferon (BOVIGAM)	Whole-blood assay on CFT responders	3 to 30 days following CFT injection

The comparative cervical test adds specificity by comparing two reactions at once: the CCT consists of two injections given in the skin of the neck, one of bovine tuberculin extract and one of avian tuberculin extract, with the response read 72 hours later and plotted on a scattergram. Because avian-type mycobacteria can cause cross-reactions on skin tests, it helps to understand how a related condition like avian tuberculosis can complicate interpretation in mixed operations.

The blood-based alternative moves faster in some cases: a whole-blood based gamma interferon test must be performed within three to 30 days following the CFT injection. If either secondary test is positive, the case does not end there. Confirmation requires tissue-level evidence, since animal necropsy and laboratory testing of samples, including microbiology, molecular biology, and histopathology, are needed to definitively diagnose bovine TB.

Interstate and Intrastate Movement Testing Requirements in Arizona

Every animal entering Arizona needs paperwork before it needs a test. State rule R3-2-602 is direct on this point: livestock may not enter the state of Arizona unless accompanied by an Arizona entry permit number documented on the Certificate of Veterinary Inspection, and all animals transported or moved into the state shall be accompanied by a valid, official Certificate of Veterinary Inspection from the state of origin. There is a narrow carve-out for animals headed straight to processing: this requirement applies regardless of species, breed, sex, class, age, point of origin, place of destination, or purpose of movement, except for livestock consigned directly to slaughter at a state or federally licensed establishment.

TB-specific testing kicks in for certain classes of breeding cattle. Unless the animal originates from an accredited herd, the owner or owner’s agent shall ensure that purebred beef breeding cattle from modified accredited states, breeding bison, dairy females, and bulls for breeding dairy cattle test negative for tuberculosis within 60 days before entry into Arizona. That said, plenty of shipments skip this step entirely because of accreditation exemptions: beef breeding cattle, breeding bison, or dairy cattle from a tuberculosis accredited herd Free State, and native commercial and purebred beef breeding cattle from an Accredited-Free State, are exempt when the accreditation or free status is documented on the health certificate.

Animals coming from a quarantined origin face tighter controls regardless of species. all conditions for the movement of animals from a quarantined area established by the quarantining authority or APHIS must be met, and animals imported from a quarantine area may be subject to additional import requirements by the State Veterinarian prior to entry into Arizona. Identification standards changed recently, too: effective November 5, 2024, the USDA animal disease traceability rule requires official ID to be both visually and electronically readable for covered classes of cattle moving interstate.

Important Note: Import rules are updated periodically by species and by origin state. Before moving cattle, bison, or trailer loads across state lines, call the Arizona State Veterinarian’s Office directly, since staff there can confirm the exact testing window that applies to your shipment.

For day-to-day compliance questions, Arizona’s own guidance tells producers to call (602) 542-4293 from 8 a.m. to 5 p.m. Arizona time, Monday through Friday, before finalizing any shipment. Owners transporting cattle should also double-check hauling rules, since improperly documented livestock trailer requirements in Arizona can compound problems at an inspection stop even when the animals themselves are TB-negative.

What Happens When a Suspect or Positive Result Occurs in Arizona

A reaction on the caudal fold test does not mean an animal is infected, but it does trigger a mandatory chain of events. Federal rules require rapid reporting: 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. From there, the animal moves into secondary testing, either the comparative cervical test, the gamma interferon assay, or direct shipment to slaughter under permit for post-mortem confirmation.

Arizona’s 2023 Pinal County case shows how this plays out in practice. The positive diagnosis was determined when the steer was retested to meet another state’s entry requirement, meaning the animal had already passed one screening before the second test caught the infection. The state’s then-Acting State Veterinarian used the case as a warning to the industry, noting the value of keeping high risk imported steers and spayed heifers separate from domestic beef and dairy breeding cattle.

Because there is no cure, options narrow quickly once infection is confirmed. As officials explained after that case, since there is no treatment for cattle infected with bovine tuberculosis, exposed cattle must be either tested or depopulated. APHIS describes the same two-path response nationally: when health officials find tuberculosis in a herd, it is managed by either depopulating the herd or by testing and removing reactor animals.

Quarantine and Herd Depopulation Rules in Arizona

A confirmed positive does not stop at one animal. Federal rules require a much wider look at exposure, defined as an investigation that is conducted by a State in conjunction with APHIS representatives, in which an official test for tuberculosis is conducted on all livestock in any tuberculosis-affected herd in a State or zone, all livestock in any herd into which livestock from the affected herd have been moved, all potential tuberculosis source herds, and all livestock herds and animals that are likely to have been exposed to the affected herd. This is why one positive steer led to a full quarantine of the Pinal County operation rather than removal of a single animal.

Once an affected herd is identified, the owner faces a choice rather than a mandate on method. Producers and regulators can apply for whole herd depopulation or develop a herd test and removal plan. If a reactor is removed and later confirmed clear, the herd is not automatically released; instead, the herd must still be evaluated and may be tested a minimum of 60 days after removal of the reactor.

1. Suspect or reactor animal identified on screening test
2. Case reported to State Animal Health Official and APHIS
3. Secondary testing or direct slaughter under permit
4. Epidemiologic investigation of the full herd and any exposed herds
5. Owner selects depopulation or a test-and-removal plan
6. Herd retested at minimum 60-day intervals until cleared

Movement restrictions apply throughout this process. Any animal leaving a quarantined operation, or originating from one, needs sign-off first: the owner or owner’s agent shall obtain prior permission from the State Veterinarian to ship or move into the state of Arizona any animal from a lot or herd from which an animal shows clinical signs of disease or positive reaction to a test required for admission to Arizona.

Penalties for Non-Compliance in Arizona

Arizona’s import rules are backed by an enforcement mechanism that kicks in the moment paperwork or testing falls short. The administrative code is unambiguous: any violation of this article is subject to a hold order pursuant to R3-2-605. In practice, that means animals moved without a valid Certificate of Veterinary Inspection, a proper entry permit, or required TB testing can be stopped and held at the point of discovery rather than allowed to continue on to their destination.

Owners moving animals from a quarantined origin carry extra exposure to enforcement. All conditions for the movement of animals from a quarantined area established by the quarantining authority or APHIS shall be met, and failing to secure prior clearance from the State Veterinarian’s Office before shipping an exposed or reactor-positive animal is treated as a separate compliance failure under the same rule set that governs clinical-sign and positive-test animals.

Common Mistake: Assuming an accredited-free label means no testing is ever required. Exemptions apply only when accreditation numbers are properly documented on the health certificate and import permit; missing paperwork can trigger the same hold order as a missing test.

Because rule numbers and testing windows can be updated by the Arizona Department of Agriculture, this article should be treated as a starting point rather than a final legal reference. Producers with an active shipment, a suspect test result, or a quarantine notice should contact the Arizona State Veterinarian’s Office directly to confirm current requirements before making any decisions about testing, movement, or herd management.