Pharmacokinetics of butorphanol tartrate in red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus).

OBJECTIVE: To determine the pharmacokinetics of butorphanol tartrate after IV and IM single-dose administration in red-tailed hawks (RTHs) and great horned owls (GHOs). ANIMALS: 6 adult RTHs and 6 adult GHOs. PROCEDURES: Each bird received an injection of butorphanol (0.5 mg/kg) into either the right jugular vein (IVj) or the pectoral muscles in a crossover study (1-week interval between treatments). The GHOs also later received butorphanol (0.5 mg/kg) via injection into a medial metatarsal vein (IVm). During each 24-hour postinjection period, blood samples were collected from each bird; plasma butorphanol concentrations were determined via liquid chromatography-mass spectrometry. RESULTS: 2- and 1-compartment models best fit the IV and IM pharmacokinetic data, respectively, in both species. Terminal half-lives of butorphanol were 0.94 +/- 0.30 hours (IVj) and 0.94 +/- 0.26 hours (IM) for RTHs and 1.79 +/- 1.36 hours (IVj), 1.84 +/- 1.56 hours (IM), and 1.19 +/- 0.34 hours (IVm) for GHOs. In GHOs, area under the curve (0 to infinity) for butorphanol after IVj or IM administration exceeded values in RTHs; GHO values after IM and IVm administration were less than those after IVj administration. Plasma butorphanol clearance was significantly more rapid in the RTHs. Bioavailability of butorphanol administered IM was 97.6 +/- 33.2% (RTHs) and 88.8 +/- 4.8% (GHOs). CONCLUSIONS AND CLINICAL RELEVANCE: In RTHs and GHOs, butorphanol was rapidly absorbed and distributed via all routes of administration; the drug's rapid terminal half-life indicated that published dosing intervals for birds may be inadequate in RTHs and GHOs.

Circulating siderophagocytes and erythrophagocytes in a corn snake (Elaphe guttata) after coelomic surgery.

Leukocytes containing nonheme iron and phagocytosed fragments of erythrocytes were found in blood smears from a corn snake (Elaphe guttata) collected 20 and 79 days after coelomic surgery (ovariosalpingectomy). Numerous immature and mitotic erythrocytes also were seen in the sample taken 20 days postsurgically. Siderophagocytes and erythrophagocytes had not been observed before surgery and were not found in multiple subsequent blood samples collected 112-602 days after surgery. Other than these hematologic abnormalities, laboratory findings were unremarkable and the snake recovered uneventfully. Based on examination of sequential blood smears, the circulating siderophagocytes were interpreted as recirculating macrophages involved in the removal of blood from the coelomic cavity after mild postsurgical hemorrhage.

Wound management in nonpsittacine birds.

Although nonpsittacine avian species comprise many different groups of birds, basic medical and surgical principles common to wound management in many vertebrate species are still applicable. This article will delve into examination and wound assessment along with therapeutic stabilization of wounded nonpsittacine birds. An overview of common case presentations that lead to a necessity for wound care are included, and may focus on one particular avian group, but the information can be used on a variety of avian species.

Management of an ingested lead foreign body in an Amazon parrot.

An adult male, double-yellow-head Amazon parrot (Amazona ochrocephala oratrix) was presented with a 36-h history of seizure episodes. On presentation, the bird was slightly obtunded, seizured once for approximately 20 sec and the seizure was controlled with midazolam. Whole body radiographs revealed a 2-mm diameter, circular, dense object in the ventriculus. A presumptive diagnosis was made of lead toxicosis, and supportive care of sc fluids and gavage feedings. Calcium disodium EDTA and chelation therapy was initiated immediately. Blood analysis revealed 1.2 ppm lead wet weight. Bulk diet therapy with freQuent high fiber gavage feedings was unsuccessful at removing the foreign body and the lead object was ultimately retrieved from theventriculus using endoscopy. Sources of lead available to the pet birds include lead weights, solder, stained glass molding, jewelry and bird toys. However, this Amazon parrot was fed portions of game birds that contained lead shots within their muscles, which is a common source of secondary lead poisoning in raptors.