Venereal shedding of ovine lentivirus in infected rams

Abstract

Objective - To assess shedding of ovine lantivirus (OvLV) in semen of infected rams with or without epididymitts. Design - Rams 1 and 2 were naturally infected with OvLV. Rams 3-6 were inoculated with OvLV strain 85/ 34 Ram 7 was inoculated with uninfected cell culture supernatatant (OvLV-negative control). 14 weeks after OvLV inoculation, rams 1-3, 6, and 7 were inoculated with Brucella ovis into the epididymis. Ram 4 was a natural case of B ovis epididymitis, and ram 5 was left noninoculated (B ovis-negative control). Blood mononuclear cells (BMNC) and semen were collected between 0 and 44 weeks after OvLV inoculation. Animals - Seven 2- to 3-year-old rams. Procedure - Infective OvLV in BMNC and semen was determined by virus isolation and subsequent OvLV-DNA amplification by polymerase chain reaction (PCR). Bronchoalveolar lavage cells collected after death were used for DNA extraction and PCR amplification. Results - OvLV was detected in the semen of rams 3 and 6, but only after B ovis inoculation. OvLV was isolated consistently from BMNC of rams 3 and 6, but only occasionally from rams 1, 2, 4, and 5. Leukocytospermia was evident in every ejaculate of all B ovis-infected rams after infection. Semiquantitative PCR determination of OvLV DNA from bronchoalveolar lavage cells revealed the highest OvLV DNA load in rams 3 and 6. Conclusions - Leukocytospermia and a high virus load in infected animals are important factors that determine shedding of OvLV in semen. Clinical Relevance - Dissemination of OvLV through contaminated semen could have important implications in the epidemiology and control of this infection.