Effect of dexamethasone administration on bulls with a localized testicular infection with bovine viral diarrhea virus.
The objective of this research was to evaluate reactivation of bovine viral diarrhea virus (BVDV) following dexamethasone treatment in 4 bulls that had previously been inoculated with BVDV, 3 of which had been demonstrated to have a localized testicular infection. Bulls were housed in an isolated pasture with in-contact steers. Beginning on day 0 of this study, all bulls received a daily dose of 0.1 mg/kg body weight (BW) of dexamethasone intravenously for 5 consecutive days. Blood was collected from the in-contact steers and semen, blood, and cerebrospinal fluid were collected from the bulls during and following dexamethasone treatment. Samples were assayed for BVDV using virus isolation and reverse transcription-nested polymerase chain reaction (RT-nPCR). Serum was assayed for antibody using standard virus isolation. Virus was not isolated from blood, cerebrospinal fluid, or semen from any of the 4 bulls during the study period. One of the bulls was positive for BVDV in semen by RT-nPCR throughout the study period. The BVDV was not recovered from any in-contact control steers during the 28-day study period, nor did any of the in-contact control steers seroconvert to BVDV. Raw semen from 1 bull that was RT-nPCR positive was intravenously inoculated into 7 seronegative steers based upon the Cornell Semen Test. The BVDV could not be recovered from the steers and none of them seroconverted to BVDV. The results indicated that reactivation of BVDV in bulls with a localized testicular infection is unlikely; however, further research is necessary to determine the full potential for BVDV transmission from bulls with a localized testicular infection.
Walz
Paul H
PH
Department of Clinical Sciences, College of Veterinary Medicine, 1500 Wire Road, Auburn University, Alabama 36849, USA. walzpau@vetmed.auburn.edu
Givens
M Daniel
MD
Cochran
Anna
A
Navarre
Christine B
CB
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D000914:Antibodies, Viral / Q000097:blood; D001774:Blood Chemical Analysis; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000188:drug therapy*; D002417:Cattle; D002555:Cerebrospinal Fluid / Q000821:virology; D003907:Dexamethasone / Q000627:therapeutic use*; D001908:Diarrhea Viruses, Bovine Viral / Q000276:immunology / Q000302:isolation & purification*; D008297:Male; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D012661:Semen / Q000737:chemistry / Q000821:virology; D013733:Testicular Diseases / Q000188:drug therapy / Q000662:veterinary*; D016896:Treatment Outcome; D014766:Viremia / Q000662:veterinary
D000893:Anti-Inflammatory Agents; D000914:Antibodies, Viral; D003907:Dexamethasone