AZDA Update: Understanding the Trich Rule Changes

As a veterinarian or rancher, you know how devastating trichomoniasis (trich) can be. It has been known to reduce a ranch’s calf crop between 10 percent and 50 percent in the first year, depending on transmission rate, according to Livestock Market Digest. That is a potentially ruinous event for a ranch. And yet, at less than $50 per bull, testing for trich is cost-effective and worthwhile.

As of June 2020, the Arizona Department of Agriculture has clarified its rules regarding trich testing for bulls upon change of ownership. Here’s a summary:

Official Trich Test

While previous rules allowed for trich cultures, bulls now must receive an individual polymerase chain reaction (PCR) test to check for trich prior to importation into Arizona or a change of ownership. (Annual cultures and pooled PCRs are still useful for herd preventive health; they’re just not recognized as official testing for AZDA purposes.) Official testing must be conducted by an accredited veterinarian. 

Testing Age

All bulls 12 months of age and older must undergo PCR testing for trich prior to being imported into the state or changing ownership. 

Test Validity

Trich test results are applicable for up to 30 days prior to importation and up to 60 days for in-state change of ownership as long as the bull is isolated from female cattle after testing.


All trich test submission forms must include the animal’s ear tag ID. If a bull does not have an ear tag at the time of testing, the veterinarian should apply one and then include the tag ID on the submission form. 

Positive Results

The testing lab and the veterinarian must immediately report all positive test results to the State Veterinarian’s Office. Include the official animal ID ear tag, brand, as well as the owner’s name, address and phone number. The veterinarian then needs to verify the bull’s ID and brand the bull with an “S” on the right hip adjacent to the tailhead. (These bulls are then sent immediately for slaughter.)

To learn more, read the full AZDA announcement on trich testing