Pharmacokinetics of oral and subcutaneous meloxicam: Effect on indicators of pain and inflammation after knife castration in weaned beef calves

PLoS One. 2019 May 24;14(5):e0217518. doi: 10.1371/journal.pone.0217518. eCollection 2019.

Abstract

Oral meloxicam is labelled for reducing pain and inflammation associated with castration in cattle in Canada, however, subcutaneous meloxicam is only labelled for pain associated with dis-budding and abdominal surgery. The aim of this project was to determine the pharmacokinetic profile of oral (PO; 1.0 mg/kg BW) and subcutaneous meloxicam (SC; 0.5 mg/kg BW), and to assess the effect of meloxicam on physiological and behavioural indicators of pain associated with knife castration in 7-8 month old calves. Twenty-three Angus crossbred beef calves (328 ± 4.4 kg BW) were randomly assigned to two treatments: PO n = 12 or SC n = 11 administration of meloxicam immediately before knife castration. Physiological parameters included salivary and hair cortisol, substance P, haptoglobin, serum amyloid-A, weight, complete blood count, scrotal and rectal temperature. Behavioural parameters included standing and lying behaviour, pen behaviour and feeding behaviour. Data were analyzed using PROC GLIMMIX (SAS), with repeated measures using mixed procedures including treatment as a fixed effect and animal and pen as a random effect. The pharmacokinetic profile of the drug including area under the curve, volume of distribution and clearance was greater (P < 0.05) in PO than SC calves. After surgery, substance P concentrations, white blood cell counts (WBC), weight and lying duration were greater (P < 0.05) in PO than SC calves, while scrotal circumference was lower (P < 0.05) in PO calves than SC calves. Although statistical differences were observed for pharmacokinetic, physiological and behavioural parameters differences were small and may lack biological relevance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / administration & dosage
  • Anti-Inflammatory Agents, Non-Steroidal / blood
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Cattle* / physiology
  • Inflammation / drug therapy
  • Inflammation / etiology
  • Inflammation / veterinary
  • Injections, Subcutaneous
  • Male
  • Meloxicam / administration & dosage
  • Meloxicam / blood
  • Meloxicam / therapeutic use*
  • Orchiectomy / adverse effects
  • Orchiectomy / methods
  • Orchiectomy / veterinary*
  • Pain / drug therapy
  • Pain / etiology
  • Pain / veterinary

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Meloxicam

Grants and funding

Funding was provided by Agriculture and Agri-Food Canada (http://www.agr.gc.ca/eng/home/?id=1395690825741) and the Beef Cattle Research Council (http://www.beefresearch.ca/) through the Canadian Beef Cattle Industry Science Cluster (ANH.21.13 AIP-CL01). The co-author Sonia Marti was partly supported by the CERCA program from Generalitat de Catalunya. This is Lethbridge Research Centre contribution # 38719006. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.