All non-virgin bulls in your herd should be tested for Trich unless your herd’s poor reproductive performance was limited to a specific breeding group.  If you can identify which bulls were involved with that breeding group, than only those bulls will need to be tested to determine if your herd is infected with Trich.

Testing bulls for Trich involves collecting a penile smegma sample. The bulls need to have at least 1 week of sexual rest prior to testing.  Sample collection, handling and shipment should be handled by a veterinarian. Trich is a difficult disease to test for and appropriate collection, handling and shipment of the sample is critical for accurate results.

All bulls that test positive should be sold for slaughter only and in accordance with state regulations. There is no appropriate treatment for Trich in bulls and infected bulls are considered to be infected for life.

Bulls that test negative on the first test should be tested again at weekly intervals until they have at least 3 negative test results regardless of the type of test the diagnostic lab runs.  Unfortunately, the test is not 100% accurate.  Although unlikely, it is possible even with 3 negative test results that an exposed bull could be truly positive for Trich.   

If you are able to initially test bulls from a specific breeding group, and you have a bull test positive, then all of the bulls that have ever been in contact, at any time, with any cows or bulls from a breeding pasture that contained a test positive animal will need to be tested for Trich as well.  In order to control Trich in your herd, all of the infected bulls must be removed.  This can be accomplished with a test and slaughter strategy and careful management of the remaining bulls, or by selling all potentially exposed bulls and purchasing virgin replacement bulls. 

Testing bulls to eliminate Trich from an infected herd requires a more aggressive testing strategy than may be necessary to meet state regulations or for disease surveillance purposes. Please discuss with your veterinarian what is needed to meet state regulations and make sure that you are in compliance.

BonDurant et. al., Vet Clinics, 2005. Christensen et. al., Aust Vet J, 1977. Christensen et. al., Aust Vet J, 1979.  Cobo et al., Therio, 2007.  Davidson et. al., JAVMA, 2011.  Mukhufhi et. al., Therio, 2003. Ondrak et. al., JAVMA, 2010. Parker et. al., J Vet Diagn Invest, 2003. Rhyan et. al., Vet Path, 1999.