Oral meloxicam given as an ancillary treatment at respiratory disease diagnosis was not associated with growth, clinical scores, or ultrasound scores in preweaned dairy calves.

Objective: To assess the efficacy of a single dose of oral meloxicam as an ancillary therapy to an antibiotic given at the time of respiratory disease identification on average daily gain (ADG), behavioral attitude, clinical respiratory, and lung ultrasound scores in preweaned dairy calves. Animals: 215 male and female Holstein, Jersey, and crossbred preweaned calves enrolled between 1 and 14 days of age at study enrollment on a single commercial dairy in the western US. Methods: The study took place from March 4, 2021, to November 21, 2021. In this double-blind placebo-controlled study, calves were given an antibiotic (1.1 mL of tulathromycin/kg, SC, once) and either a placebo (1 mg of lactose monohydrate/kg, in a gelatin capsule) or oral meloxicam (1 mg/kg) at the time of respiratory disease identification. Behavioral attitude, clinical respiratory, and lung ultrasound scores and ADG were assessed in preweaned dairy calves at different time points including the next health examination, 1 week later, or at weaning. Results: There was no association between treatment (placebo vs meloxicam) on ADG or respiratory disease status at weaning (P > .05). There was no effect of treatment on behavioral attitude, clinical respiratory, or lung ultrasound scores at the next health examination or 1 week later (P > .05). Clinical Relevance: The present study did not provide evidence that oral meloxicam given once is beneficial for growth, behavioral attitude, or clinical or lung ultrasound scores.