The infection rate of T. foetus in these herds ranged from 0 to 29 per 1000 bulls, depending on herd and year sampled. Because of the surveillance program, and stringent control measures, T. foetus has been controlled on Provincial Grazing Reserves, but the parasite remains prevalent in home bulls. Diagnosis of T. foetus is based mainly upon microscopic examination of preputial washes from bulls or cervicovaginal secretions from cows. Three weekly samples are needed from bulls that have been sexually rested for 2 weeks prior to sampling.
Cows require a minimum of six tests.
Test specificity is an important obstacle for the accurate diagnosis of T. foetus . Closely related, but pathogenic, trichomonads may be confused for T. foetus or, in the case of PCR, cross react with T. foetus resulting in a false positive diagnosis. Definitive identification of T. foetus, by culture, demands that the organism is viable. Ensuring the organism remains viable until testing is performed is a concern. PCR, on the other hand, will detect T. foetus regardless of its viability, providing the genome remains intact.