The effect of a single dose of flunixin meglumine on shedding of inoculated bovine herpesvirus-1 in weaned calves

Background The effects of a Food and Drug Administration approved non-steroidal anti-inflammatory drug (NSAID) on bovine herpesvirus-1 (BHV-1) shedding in cattle has not been investigated. Hypothesis/Objectives The hypothesis of this study was that a single dose of flunixin meglumine would increase the magnitude and duration of viral shedding in calves inoculated with BHV-1. Animals Twelve, 6- to 8-week-old, commercial Holstein cross-bred steer calves purchased for research, and BHV-1 polymerase chain reaction (PCR) negative on intake (day-4). Methods In this randomized-control study, calves were equally divided into treatment (FM) and control (CON) groups. All calves were inoculated intranasally with approximately 4 mL of 1 × 105 TCID50 of BHV-1. Nasal swabs for BHV-1 PCR testing were collected every 24 h after inoculation. Calves in the FM group were treated with 2.2 mg/kg of flunixin meglumine intravenously once after the first BHV-1 PCR positive sample. Magnitude and duration of viral shedding between groups was compared, and a P-value of <.05 was considered significant. Results Least square mean of the total Log10 AUC of the FM group was 6.11 (95% CI: 4.62-7.60) and CON group was 7.49 (95% CI: 6.00-8.98). The FM group’s mean duration from initial to last positive PCR was 7.33 days ± SD: 4.41 and the CON group’s mean was 9.5 days ± SD: 5.80. Conclusions and clinical importance Intranasal inoculation with BHV-1 resulted in a wide range of shedding magnitude and duration. Flunixin meglumine administration in BHV-1 challenged calves did not result in an increase in magnitude or duration of viral shedding.