Analgesia is becoming increasingly important in veterinary medicine, and little research has been performed that examined pain control in avian species. Tramadol is a relatively new drug that provides analgesia by opioid (μ), serotonin, and norepinephrine pathways, with minimal adverse effects. To determine the pharmacokinetics of tramadol and its major metabolite O-desmethyltramadol (M1) in eagles, 6 bald eagles (Haliaeetus leucocephalus) were each dosed with tramadol administered intravenously (4 mg/kg) and orally (11 mg/kg) in a crossover study. Blood was collected at various time points between 0 and 600 minutes and then analyzed with high-performance liquid chromatography to determine levels of tramadol and M1, the predominate active metabolite. The terminal half-life of tramadol after intravenous dosing was 2.46 hours. The maximum plasma concentration, time of maximum plasma concentration, and terminal half-life for tramadol after oral dosing were 2156.7 ng/ml, 3.75 hours, and 3.14 hours, respectively. In addition, the oral bioavailability was 97.9%. Although plasma concentrations of tramadol and M1 associated with analgesia in any avian species is unknown, based on the obtained data and known therapeutic levels in humans, a dosage of 5 mg/kg PO q12h is recommended for bald eagles. Pharmacodynamic studies are needed to better determine plasma levels of tramadol and M1 associated with analgesia in birds.

The luteinizing hormone–releasing hormone agonist leuprolide acetate is used commonly to manage reproductive problems in pet birds. To determine the effect of leuprolide acetate on plasma and fecal hormone levels in a psittacine species, a single 800 µg/kg dose of the 30-day depot form of leuprolide acetate was administered IM in 11 healthy, nonbreeding adult Hispaniolan Amazon parrots (Amazona ventralis), and plasma and fecal hormone levels were measured before and after leuprolide administration. At pooled baseline to 21 days postleuprolide acetate administration, sample collection day was significantly associated with plasma 17β-estradiol and androstenedione levels and fecal 17β-estradiol levels (evaluated in females only). Both plasma androstenedione and plasma 17β-estradiol levels decreased significantly from baseline to a nadir at 7 days postleuprolide acetate administration but did not differ significantly 14 days later from that nadir or from pooled baseline samples, suggesting that the effect of leuprolide on hormone levels remained about 2 weeks. Fecal 17β-estradiol levels increased significantly from the nadir at 7 days postleuprolide to 21 days postleuprolide administration, with trends of the level at 21 days postleuprolide being higher than the pooled baseline level and of decreasing levels from pooled baseline to 7 days postleuprolide administration. Plasma luteinizing hormone and fecal testosterone levels did not change significantly from baseline levels after leuprolide administration over the 2-day period. No significant correlations were found between plasma hormone and fecal hormone levels. These results suggest that measurement of plasma androstenedione, plasma 17β-estradiol, and fecal 17β-estradiol levels might be useful in assessing the effects of 30-day depot leuprolide acetate in Hispaniolan Amazon parrots.

Use of external skeletal fixator–intramedullary pin tie-in (ESF-IM pin tie-in) fixators is an adjustable and effective method of fracture fixation in birds. The objective of this study was to evaluate the elements of the ESF-IM tie-in configuration used in birds. Ten variations of constructs were applied to a plastic bone model with a standard gap. Variants included non-tied and tie-in configurations, use of a 6- or 10-mm acrylic bar or a thermoplastic connecting bar, variation in the placement of the proximal fixation pin, use of 1.1-mm (0.045-in) or 1.6-mm (0.062-in) fixation pins, and configurations of 2, 3, or 4 fixation pins. The various constructs were loaded in bending, torque, and compression, and response variables were determined from resulting load-displacement curves (stiffness, load at 1-mm displacement). Results showed that, by using the tie-in configuration, increasing the diameter of the acrylic connecting bar, and increasing the diameter or number of fixation pins, each significantly increased the stiffness in all assessments. Placing the fixation pin distally in the proximal bone model segment increased the stiffness in bending, and adding a fixation pin to the distal bone model segment increased the stiffness in torque and bending. These results quantified the relative importance of specific parameters that effect stiffness and safe load of the ESF-IM tie-in construct as applied to a plastic bone fracture model.

Use of external skeletal fixator-intramedullary pin (ESF-IM) tie-in fixators is an adjustable and effective method of fracture fixation in birds. The objective of this study was to determine the contribution of each of the following parameters to the compressive and torsional rigidity of an ESF-IM pin tie-in applied to avian bones with an osteotomy gap: 1) varying the fixation pin position in the proximal bone segment and 2) increasing the number of fixation pins in one or both bone segments. ESF-IM pin tie-in constructs were applied to humeri harvested from red-tailed hawks (Buteo jamaicensis) (n  =  24) that had been euthanatized for clinical reasons. Constructs with a variation in the placement of the proximal fixation pin and with 2, 3, or 4 fixation pins applied to avian bone with an osteotomy gap were loaded to a defined displacement in torque and axial compression. Response variables were determined from resulting load-displacement curves (construct stiffness, load at 1-mm displacement). Increasing the number of fixation pins from 1 to 2 per bone segment significantly increased the stiffness in torque (110%) and compression (60%), and the safe load in torque (107%) and compression (50%). Adding a fixation pin to the distal bone segment to form a 3-pin fixator significantly increased the stiffness (27%) and safe load (20%) in torque but not in axial compression. In the configuration with 2 fixation pins, placing the proximal pin distally in the proximal bone segment significantly increased the stiffness in torque (28%), and the safe load in torque (23%) and in axial compression (32%). Results quantified the relative importance of specific parameters affecting the rigidity of ESF-IM pin tie-in constructs as applied to unstable bone fracture models in birds.

Two birds from a zoological collection suffered fatal intestinal obstruction after each ingested single particles of polyacrylamide gel. Polyacrylamide gel, used in soils for gardening and agriculture, exists as small granules in the dehydrated state but expands markedly upon exposure to water. Polyacrylamide gel might, therefore, be an unrecognized hazard for captive and wild birds and other small animals if consumed.

A 7-day-old gentoo penguin (Pygoscelis papua) was found dead and postmortem examination revealed impaction of the ventriculus with feathers. A review of mortality in gentoo penguin chicks from 1997 to 2007 at that institution revealed another case of feather impaction of the ventriculus in a 4-week-old chick, a sibling of the previous chick. A third case of gastrointestinal impaction occurred in a 24-day-old king penguin (Aptenodytes patagonicus) with omphallitis and enteritis. In this chick, a fibrin mat produced a complete obstruction of the intestine at the level of Meckeĺ's diverticulum.

A 3.5-year-old umbrella cockatoo (Cacatua alba) was presented because of the development of widely disseminated subcutaneous nodules. The diagnostic work-up included a complete blood count, plasma biochemical analysis, and whole body radiographs. Biopsy samples of the skin lesions were submitted for histopathologic evaluation, bacterial culture and sensitivity testing, immunohistochemistry staining, and acid-fast staining. The diagnosis was nonepitheliotropic cutaneous B-cell lymphoma with a leukemic blood picture. The bird was treated with a chemotherapeutic regimen consisting of vincristine and chlorambucil for 17 weeks. During treatment, the complete blood count was monitored every 1–3 weeks, and the plasma biochemical analysis was monitored every 3–4 weeks. The bird was in partial remission on week 9. On week 17, the bird became acutely ill and was fluffed, depressed, anorectic, and anemic. The chemotherapeutic regimen was discontinued. At this time, the bird had a consistent lymphocytosis but no neoplastic lymphocytes were seen in the general circulation. At week 29 the bird was in complete remission and remains in complete remission 8 years after chemotherapy was discontinued.

A 24-year-old female umbrella cockatoo (Cacatua alba) was examined because of a subcutaneous swelling of the left shoulder. Radiographs of the left wing revealed boney proliferation of the left proximal humerus. At surgery, an unencapsulated infiltrative nonpigmented mass within the subcutaneous tissue and skeletal muscle was identified overlying the left humerus. The mass was surgically excised and submitted for histologic examination; however, the cockatoo died after excision. Histologically, the mass was composed of nests and sheets of pleomorphic neoplastic cells with a high mitotic index and extensive necrosis. Rare neoplastic cells contained fine brown cytoplasmic granules that stained black with Fontana-Masson, confirming the presence of melanin pigment. The histomorphologic diagnosis was consistent with an anaplastic malignant melanoma of subcutaneous tissues.

An extracapsular stabilization technique was used to repair cruciate ligament ruptures in a trumpeter hornbill (Bycanistes bucinator) and an African grey parrot (Psittacus erithacus). The hornbill demonstrated cranial drawer motion and severe rotational instability of the stifle from ruptures of the cranial and caudal cruciate ligaments and stifle joint capsule. The luxation was reduced, and the fibula was cranially transposed, in relation to the tibiotarsus, and anchored with 2 positive profile threaded acrylic pins. A lateral extracapsular stabilization was then performed. The African grey parrot had a traumatic stifle luxation, and an open reduction and a lateral extracapsular stabilization were performed. Both birds regained function of the affected leg by 1 month after surgery. Extracapsular stabilization allows motion of the stifle joint to be maintained during the postoperative recovery period, an advantage over rigid stabilization. Maintaining motion in the stifle joint facilitates physical therapy and can aid in full recovery after avian stifle injuries.

A large ventricular foreign body was identified on radiographs in a captive-bred gyr falcon (Falco rusticolus) that was presented for paresis and swollen abdomen. On endoscopic examination, a large shiny mass was visible in the ventriculus. An ingluviotomy was done, and pieces of the mass, which consisted of a ball of artificial grass fibers, were removed by using a rigid endoscope and grasping forceps. Subsequently, 4 more ingluviotomies were required to gain endoscopic access to the ventriculus and to allow staged removal of the mass in a piecemeal fashion. Feeding the falcon a feathered quail and allowing it to cast naturally removed the remaining fibers of the mass. No deleterious effects were observed in the bird.

There are so many issues in the news every day that it is hard to keep up. As veterinarians, we try especially hard to pay attention to issues that relate to animals, but, with all the obligations we face every day in our jobs and with our families, some issues slip through the cracks. One issue, H.R. 669, the Non-native Wildlife Invasion Prevention Act, should not. It is too important. For those of you who have not heard about this proposed legislation, the underlying intent of this bill is, according to the American Veterinary Medical Association (AVMA) (and as published in The AVMA Advocate, 2009), to “establish a risk-assessment process to prevent the introduction into, and establishment in, the United States of non-native wildlife species that will cause or are likely to cause economic or environmental harm or harm to other animal species' health or human health.” This legislation would create 2 species lists for the United States: approved species and unapproved species. As the AVMA notes, “For species not already included on these 2 lists, H.R. 669 tries to account for this by providing a method to submit proposals for importation of a species. Upon submission of this request, the Secretary of the Interior, through the Fish and Wildlife Service, is required to determine if the species is (1) approved for importation and placed on the approved species list, (2) not approved for importation and placed on the unapproved species list, or (3) the Secretary has insufficient scientific and commercial information to make a determination.” Once species are classified, the breeding, sale, trade, and interstate transport of any species on the unapproved list would be prohibited. As the AVMA notes, what is unclear is what happens if there is insufficient scientific evidence to make a determination about a particular species. In addition, “H.R. 669 fails to take into consideration variations in climate, geology, hydrology and native species of a particular geographical region of the United States. With states as diverse as Hawaii, Alaska, Indiana and New Hampshire, it is difficult, if not impossible to legislate a one size fits all approach.”

H.R. 669 has ramifications for all exotic species and for all those who work with exotic species. Although the bill was defeated in the House of Representatives, the AVMA recently commented, “It is our understanding that H.R. 669 will be re-written to more appropriately address the issue of invasive species.” Consequently, it is something we should all be thinking about. To this end, I have invited 5 participants knowledgeable about H.R. 669 to share their thoughts about this potential legislation. The participants are Susan Clubb, DVM, Dipl ABVP (Avian Practice), Rainforest Clinic For Birds & Exotics, Inc, Loxahatchee, FL, USA; Robert Groskin, DVM, Englewood Animal Hospital, Englewood, NJ, USA; Tarah Hadley, DVM, Dipl ABVP (Avian Practice), Atlanta Hospital for Birds and Exotics Inc, Lithonia, GA, USA; James M. Harris, DVM, Mayfair Veterinary Clinic, Sandy Bay, Tasmania, Australia; and Bruce Nixon, DVM, Animal Emergency Hospital of North Texas, Grapevine, TX, USA. I hope that their comments will be enlightening, thought provoking, and motivating to each of us to voice our own opinions about this daunting issue.