Pharmacokinetics of a Single Dose of Oral and Subcutaneous Meloxicam in Caribbean Flamingos (Phoenicopterus ruber ruber)

To determine the pharmacokinetics of meloxicam in Caribbean flamingos ( Phoenicopterus ruber ruber), a pilot study was performed first, followed by a complete pharmacokinetic study. Four healthy birds were divided into 2 groups and administered 1 mg/kg of either oral (n = 2) or subcutaneous (n = 2) meloxicam. Plasma meloxicam concentrations were determined with liquid chromatography-mass spectrometry. Based on the pilot study results, 12 healthy birds were assigned into 2 groups and administered either 3 mg/kg PO (n = 6) or 1.5 mg/kg SC (n = 6) of meloxicam. Blood samples were collected at baseline and at 9 time intervals per group after administration of meloxicam in all flamingos. Plasma concentrations after administration of 3 mg/kg PO meloxicam reached a mean maximum plasma concentration of 1.449 μg/mL at 2.35 hours with a terminal half-life of 1.832 hours. After administration of 1.5 mg/kg SC meloxicam, maximum plasma concentration was 4.059 μg/mL at 0.91 hour with a terminal half-life of 1.104 hours. The plasma profile from the main oral study (3 mg/kg PO) differed markedly from the pilot study (1 mg/kg PO), suggesting a delayed absorption with the higher dose and lack of dose proportionality. The different doses for subcutaneous administration resulted in a proportional change in plasma concentrations. Further studies are needed to evaluate the effects of the drug volume administered and fasting status when oral dosing is used. Future studies are also needed to investigate multiple-dose pharmacokinetics of meloxicam and to determine the therapeutic meloxicam plasma concentration in Caribbean flamingos.