Osmotic pump maintains plasma concentrations of meloxicam for 6 days after orthopedic surgery in pigeons (Columba livia)

Abstract

OBJECTIVE To determine the plasma concentration of meloxicam delivered via an osmotic pump in pigeons undergoing orthopedic surgery and if an osmotic pump is a suitable alternative to repeated oral administration of this drug. ANIMALS 16 free-ranging pigeons presented for rehabilitation with a wing fracture. PROCEDURES An osmotic pump filled with 0.2 mL of 40 mg/mL meloxicam injectable solution was implanted subcutaneously in the inguinal fold of 9 pigeons under anesthesia for orthopedic surgery. The pumps were removed 7 days postsurgery. Blood samples were collected before pump implantation (time 0) and 3, 24, 72, and 168 hours after pump implantation in 2 pigeons in a pilot study then at 12, 24, 72, and 144 hours in the 7 pigeons of the main study. The blood of 7 other pigeons receiving meloxicam at 2 mg/kg, PO, every 12 hours was also sampled between 2 to 6 hours after the last meloxicam administration. Plasma meloxicam concentrations were measured via high-performance liquid chromatography. RESULTS The plasma concentration of meloxicam was maintained at significant levels from 12 hours to 6 days after osmotic pump implantation. Median and minimum plasma concentrations in implanted pigeons were maintained at the same or higher level than those measured in pigeons that received meloxicam at a dose known to be analgesic in this spe-cies. No adverse effects attributable to either osmotic pump implantation and removal or meloxicam delivery were observed in this study. CLINICAL RELEVANCE Plasma concentrations levels of meloxicam in pigeons implanted with osmotic pumps were maintained at a simi-lar concentration or higher than the suggested analgesic meloxicam plasma concentration in this species. Thus, osmotic pumps could represent a suitable alternative to the frequent capture and handling of birds for analgesic drug administration.