Comparative pharmacokinetics of meloxicam between healthy postpartum versus mid-lactation dairy cows

Abstract

Pain is a physiological response that cattle often experience as a result of pathological conditions or through implementation of common management procedures. There is a need for effective modalities of analgesia to manage pain and limit welfare concerns in lactating dairy cattle. Meloxicam has been shown to be an effective treatment to decrease lameness-associated pain related to udder edema in the postpartum period.¹ To date, transdermal flunixin meglumine is the only available labeled product for bovine pain control in the United States. Non-steroidal anti-inflammatory (NSAIDs) drugs, like meloxicam and flunixin meglumine, are commonly used by veterinarians. Previous work by our team has found differences in plasma and milk concentrations of oral meloxicam between postpartum and mid-lactation dairy cows.² This work displayed an increased relative bioavailability in postpartum cows and longer milk residue. Due to this discovery, longer withdrawal periods for meat and milk are necessary in the postpartum cow following meloxicam therapy. This prior work has precipitated a need to further characterize the bioavailability of oral administration of meloxicam in various stages of lactation and establishment of withdrawal periods in the postpartum dairy cow. We hypothesize that meloxicam will be more bioavailable in postpartum relative to mid-lactation dairy cows and therefore require longer withdrawal times.