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Animal Diseases and Biosecurity

​Trichomoniasis is a venereal disease of cattle, caused by the protozoa Trichomoniasis foetus, commonly referred to as "Trich". Trich causes devastating economic losses in infected herds because of reduced calving rates or increased length of calving season. Trichomoniasis has been recognized in all major cattle-producing countries during the past 100 years. Because most infected animals do not show any symptoms, the first sign of trouble may be a lower than normal calving rate in herds using natural breeding. In 1990, a random survey of California beef herds showed that more than 15% of the herds had at least one infected bull. The organism that causes Trichomoniasis in cattle is related to the protozoa Trichomonas vaginalis that causes a similar venereal disease in humans. Another similar organism also causes Trichomoniasis in birds, but this infection is primarily a skin and lung infection. 

S​ymptoms and transmission: 

Bulls are typically asymptomatic for this disease. They spread the organism cow to cow via breeding. The infection in cows then causes early abortions and trouble with fertility until they are able to clear the infection. It takes months before a cow is able to clear the infection and maintain a healthy pregnancy. Infected bulls are not able to clear the infection, and continue to infect cows each breeding season. They need to be identified and removed from the breeding herd. ​


Buy virgin bulls or test any new bulls before adding to the herd. Do not comingle herds. Test all bulls annually to ensure your herd remains clean.  

Currently Oregon’s highest risk areas for trich are present in the public grazing areas of Malheur, Harney, Lake, Klamath, and Jackson counties. 

Oregon Test-Positive Program 

Bovine Trichomoniasis is a reportable disease in Oregon. Notification of disease diagnosis should be immediately reported to the Oregon State Veterinarian. 

Veterinarians working within the trichomoniasis program that are testing bulls in Oregon need to be “trich certified”. Certification requires training in trichomoniasis sample collection and laboratory procedures. Oregon is currently accepting the certification of veterinarians certified in states that have a certification process. Recertification is currently due every 5 years, but it can be more often if new information about trich testing or lab procedures becomes available. Any veterinarian  interested in becoming Trich certified in Oregon, should contact the animal health office at 503-986-4680. 

Once trichomoniasis is diagnosed in a herd, all further testing within that herd and in the exposed herds must be done by a trich certified veterinarian. Retesting of the herd and all exposed herds are required to be tested for trich by PCR and the positive index herd is further required to test annually until negative. An epidemiologic disease investigation is started. Positive bulls will be removed from the herd to prevent further spread of disease. Positive bulls must be disease branded and can only be transported using a VS 1-27 Movement of Diseased Livestock form that is issued by the State Veterinarian's office. Veterinarians will need to work with the State Veterinarians office to obtain this form prior to movement of infected animals off the property.  

Veterinarians not using the ODA laboratory should fax their test/tag report forms to ODA as soon as the testing is complete. Those reports are filed by clinic and their immediate access greatly facilities the work up of a positive case. This includes reporting any virgin bulls that were identified for grazing purposes but not tested for trich.  Additionally, such reports often aid in the identification of the owner of strayed bulls or the reassurance to a concerned stock grower that testing has been done. 

At least one county in Oregon, Malheur, requires the OR official trich tag on all bulls that will go to public grazing in that county. Additionally, some grazing associations require the same identification.  Frequently, the testing veterinarian does not know the grazing destination of the bulls being tested, so tagging of all bulls tested can facilitate the management of bulls.  

Surrounding states (specifically ID, CA, MT, WY, and NV) have strict regulations in place regarding trichomoniasis. In order to meet CVI, import permit, or pasture-to-pasture permit requirements, some identification system needs to be in place. Oregon’s official trich tag, combined with a USDA official identification device provides such documentation. 

Trichomoniasis Ear Tags 

The trich program year begins September 1 and runs through August 31, and a different tag color applies for each trich year. For example, the 2022 trich year will begin September 1, 2021. As of that date, the test tags applied should be White and the button will be printed 2022. 

The Oregon Trich Ear Tag must be tamperproof, 3” wide x 2 1/4” tall with a self-piercing male button printed with the current trich year. The female portion of the tag will have OR TRICH printed above a four or five-digit number.   

Tags meeting the identification requirement are in stock at MWI Veterinary Supply (1-800-8243703, specify TRICH TAG OREGON) and available for immediate shipment. The tags come in bags of 25. Due to the very specific nature of these tags, they are non-returnable to the supplier. Veterinarians are free to order their own tags so long as they meet the size, color, and printed information specifications of the program. There might be considerable time lag for such custom tag orders so they should be planned well in advance.  Any leftover program tags can be utilized on the next color tag cycle.   

Trich tag colors change each year in a 5-year rotation as follows: 

  • ​2021 – Green 
  • 2022 – White 
  • 2023 – Orange 
  • 2024 – Blue  
  • 2025 – Yellow   

Continuity of identification of the bull from year to year should be maintained either by a ranch tag, tattoo, EID or a silver alphanumeric USDA tag.  

Trich Tags are not considered a form of official ID 


Animal Health
635 Capitol Street NE
Salem, OR 97301
Phone: 503-986-4680
Fax: 503-986-4734