Acute immunological responses to a combined viral-bacterial respiratory disease challenge in heifers administered transdermal flunixin meglumine

Authors: WORD, ALYSSA - Texas Tech University; Broadway, Paul; LIANG, Y - Texas Tech University; NEWCOMB, HAROLD - Merck Animal Health; Sanchez, Nicole; HOLLAND, BEN - Cactus Feeders, Inc; ELLIS, GUY - Merck Animal Health; LITTLEJOHN, BRITTNI - Texas A&M University; CAPIK, SARAH - Texas A&M Agrilife; FUSELIER, A - Merck Animal Health; HUTCHESON, JOHN - Merck Animal Health; BALLOU, MICHAEL - Texas Tech University; Carroll, Jeffery - Jeff Carroll

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 11/21/2017
Publication Date: 3/1/2018
Citation: Word, A.B., Broadway, P.R., Liang, Y.L., Newcomb, H., Sanchez, N.C., Holland, B.P., Ellis, G.B., Littlejohn, B.P., Capik, S., Fuselier, A.J., Hutcheson, J.P., Ballou, M.A., Carroll, J.A. 2018. Acute immunological responses to a combined viral-bacterial respiratory disease challenge in heifers administered transdermal flunixin meglumine. Journal of Animal Science Supplement. 96 (Suppl-1): 49.

Interpretive Summary:

Technical Abstract: Time of flunixin meglumine transdermal (FTD; Finadyne Transdermal, Merck Animal Health, Summit, NJ) administration relative to a viral-bacterial challenge was evaluated in beef heifers. Thirty-two beef heifers (170 ± 21.1 kg BW) were randomly assigned to one of four treatments: 1) Control (CON), receiving no FTD, 2) Arrival (ARR), receiving FTD the day after arrival (d -6; 3.33 mg/kg BW), 3) Viral (VIR), receiving FTD at the time of viral challenge (d -3) , or 4) Bacterial (BAC), receiving FTD at the time of bacterial challenge (d 0). On d -6, all cattle were fitted with an indwelling vaginal temperature recording device and placed into outdoor group-pens according to treatment. On d -3, all cattle were challenged intra-nasally with 1x10 exp 8 PFU bovine herpesvirus-1 (BHV-1) and returned to the outdoor group-pens. On study d 0, each animal was challenged intra-tracheally with an average dose of 1.18 x 10 exp 6 CFU Mannheimia haemolytica, fitted with an indwelling jugular catheter, and was moved into an individual stanchion in an environmentally- controlled barn. Blood samples were collected on d -6, d -3, and at 1-h (serum) or 2-h (complete blood cell counts) intervals from 0 to 8 h, and at 12, 24, 36, 48, 60, 72, and 144 h relative to M. haemolytica challenge. Data were analyzed using the Mixed procedure of SAS specific for repeated measures with fixed effects of treatment, time, and their interaction. No significant treatment × time interactions were detected (P = 0.19). Vaginal temperature was affected by treatment (P = 0.04) such that it was greatest for CON compared to VIR and BAC, and similar between CON and ARR. While change in total leukocyte concentration was similar among treatments (P = 0.52), change in neutrophil concentration tended (P = 0.09) to be greatest in CON compared to all other treatments. Lymphocyte concentration, while not significant (P = 0.16), was numerically decreased in CON compared to other treatments, causing neutrophil:lymphocyte ratio to be greatest in CON (P = 0.03). Interleukin-1 beta (IL-1 beta), IL-4, and IL-6 concentrations were similar among treatments (P = 0.44). Interferon-gamma was not different among treatments (P = 0.21). These data indicate that FTD transdermal is effective for reducing febrile severity and decreasing circulating neutrophil concentration in response to a viral-bacterial challenge when applied during the immunological challenge, which may expedite challenge recovery. Applying FTD prior to challenge did not impact immunological response to challenge.