Major factors associated to persistence of bovine trichomoniasis in a mandatory control plan: A eight year retrospective study in La Pampa, Argentine.

Bovine trichomoniasis is a venereal disease caused by the flagellate protozoan Tritrichomonas foetus. Infection is related to low conception rates and would have significant impact on calf crop. The state of La Pampa started in 2006 an unprecedented mandatory control program for eradication of bovine trichomoniasis. The compulsory participation of all cattle producers and the yearly control of every bull should be followed by culling of every positive animal. This retrospective study on data from eight years of the control plan showed that 80% of farms had a single year of positive tests. In these farms, positive tests showed a strong decay of disease during the first years that reached a baseline by 2012. A non negligeable proportion of positive bulls in this group can be attributed to false positive tests. Oppositely, farms with two or more years of positive diagnosis accounted for a great proportion of recent cases. These farms were more likely related to less intensive control measures. The non exclusion of carrier bulls is the major factor contributing to the persistance of bovine trichomoniasis.