Semen changes in boars after experimental infection with pseudorabies virus.

Two groups of adult boars were inoculated with a field strain of pseudorabies virus (PRV) by intranasal droplet; one group was given 5 x 10(5) median tissue culture infective doses (TCID50), and the other, 5 x 10(6) TCID50. (A third group was maintained as controls.) Ejaculates were examined twice a week for volume, sperm numbers, sperm morphology, and presence of PRV. Severe clinical disease with fever followed administration of the larger virus dose. Death (one boar), testicular degeneration, and transient elevation in spermatozoa with proximal cytoplasmic droplets were seen in different members of this group. The smaller dose resulted in seroconversion, but did not produce signs of disease. In this group, volume, sperm numbers, and sperm morphology did not decline when compared with base-line values or data of control animals. The virus was not isolated from semen. Effects of PRV infection on semen quality in boars seem to be related to the associated clinical signs of systemic disease.