Meloxicam—For the Birds?

The selective COX-2 inhibitor meloxicam is commonly prescribed for extralabel use in companion birds because of its availability in oral and injectable forms at useful concentrations. This study assessed potential adverse effects of oral meloxicam in Hispaniolan Amazon parrots (Amazona ventralis) at doses previously identified as therapeutic. Twelve healthy parrots were assigned to receive either meloxicam oral suspension (1.6 mg/kg PO q12h) with 2.5 mL tap water (n = 8) or the equivalent volume of tap water only (n = 4) for 15 days. CBC, serum chemistry analysis, and clotting times were measured, as well as _N-_acetyl-β-D-glucosaminidase (NAG) activity as a marker of renal damage. Urinalysis and urine NAG activity were assessed, and feces were checked for occult blood. Treated birds had significant increases in white blood cells (WBCs) and decreases in packed cell volume (PCV) after treatment. PCV in treated birds was significantly lower than in the control group; however, WBC counts and PCV for all birds remained within the reference range throughout the study. There were no effects of treatment on clotting times, uric acid concentration, serum NAG activity, urinalysis variables, or fecal occult blood. Although no clinically relevant changes were seen secondary to meloxicam treatment in these healthy parrots, additional studies are needed, and patients should be evaluated for organ dysfunction before use.

Commentary

Pharmacokinetic studies on avian and exotic pets are a much needed addition to the peer-reviewed literature as there is much extralabel use, dosage extrapolation, and confusion with metabolic scaling. Meloxicam is the most commonly used NSAID with a variety of applications in pet birds, but despite the many papers evaluating pharmacokinetics and doses in a variety of bird species, little is known about adverse effects. Although this study was done on a small, species-specific number of healthy Amazon parrot cases, and the method of urine sampling and statistics on a small population was questionable, the results help us better understand the lower likelihood of adverse effects when using a higher dose and frequency of meloxicam, thereby resulting in better analgesia for patients.—Anthony A. Pilny, DVM, DABVP (Avian)