Marion Desmarchelier

Analgesic effects of meloxicam administration on postoperative orthopedic pain in domestic pigeons (Columba livia)

OBJECTIVE To assess the analgesic effects of 2 doses of meloxicam on the degree of postoperative orthopedic pain in pigeons. ANIMALS 21 domestic pigeons (Columba livia). PROCEDURES In each bird, a standardized osteotomy of 1 femur was performed and the fracture was immobilized with an intramedullary pin. Birds were randomly allocated to receive saline (0.9% NaCl) solution (control) or meloxicam (0.5 mg/kg [low dose] or 2.0 mg/kg [high dose]). The first treatment was administered i.m. after surgery was completed. Subsequent treatments were administered p.o. every 12 hours for 9 days. Degree of postoperative pain was assessed for the first 4 days after surgery by use of 3 methods: an electronic perch for assessment of weight-bearing load differential of the pelvic limbs, 4 pain scales, and analysis of video-recorded partial ethograms for bird activity and posture. RESULTS No significant differences were observed between the control group and the low-dose meloxicam group in any tested variable. The high-dose meloxicam group had a greater degree of weight bearing on the affected limb from the second to the fourth postoperative day as well as lower pain scores for at least the first 2 postoperative days, compared with the other groups. Return to presurgical behavior was achieved faster in pigeons that received high-dose meloxicam than in the other groups. No adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE Administration of meloxicam at 0.5 mg/kg appeared ineffective in minimizing postoperative orthopedic pain in pigeons, but the 2.0 mg/kg dose provided quantifiable analgesia that appeared safe in this species in experimental conditions.

MONITORING OF THE VENTILATORY STATUS OF ANESTHETIZED BIRDS OF PREY BY USING END-TIDAL CARBON DIOXIDE MEASURED WITH A MICROSTREAM CAPNOMETER

Abstract The relationship between end-tidal partial pressure of carbon dioxide (PETCO2), arterial partial pressure of carbon dioxide (PaCO2), and blood pH in isoflurane-anesthetized raptors was evaluated. PaCO2 and pH were determined in serial arterial samples from isoflurane anesthetized birds and compared with concurrent end-tidal partial pressure of carbon dioxide measured with a Microstream sidestream capnograph. Forty-eight paired samples, taken from 11 birds of prey (weighing 416–2,062 g), were used to determine correlations coefficients between PaCO2 and PETCO2, and between PETCO2 and pH. Limits of agreement between PaCO2 and PETCO2 also were calculated. Strong correlations were observed between PaCO2 and PETCO2 (r = 0.94; P < 0.0001) as well as between PETCO2 and pH (r = −0.90; P < 0.0001). However, the level of agreement between PaCO2 and PETCO2 varied considerably. Low values of PETCO2, ranging from 18 to 29 mm Hg, exceeded the concomitantly measured values of PaCO2 by an average of 6.0 mm Hg (6.0 ± 1.9 mm Hg; mean ± SD). Conversely, high values of PETCO2, ranging from 50 to 63 mm Hg, were on average 7.6 mm Hg (7.6 ± 9.8 mm Hg) lower than values of PaCO2. In the 30 to 49 mm Hg range for PETCO2, the difference between PETCO2 and PaCO2 was on average 1.0 mm Hg (1.0 ± 8.5 mm Hg). These results suggest that the capnograph used provided a sufficiently accurate estimation of arterial partial pressure of carbon dioxide for birds weighing >400 g and receiving manual positive ventilation with a Bain system. In our study, the linear relationship observed between the pH and the end-tidal partial pressure of carbon dioxide suggested that the monitoring of end-tidal partial pressure of carbon dioxide also can be useful to prevent respiratory acidosis.

FIELD USE OF ISOFLURANE AS AN INHALANT ANESTHETIC IN THE AMERICAN MARTEN (MARTES AMERICANA)

We evaluated the effectiveness and practicality of using isoflurane as an inhalation anesthetic with oxygen as a gas carrier for American martens (Martes americana) in a field setting. Sixty-eight martens were trapped in the Waswanipi Cree Model Forest (Québec, Canada) from October to November 2005 and anesthetized with isoflurane in 100% oxygen (1 l/min) using a face mask. Induction setting of isoflurane was 3% for all animals. Mean (±SD) length of induction was 1.8±1.2 min. Maintenance isoflurane settings ranged from 1% to 4%. Procedures lasted an average of 16.4±7.1 min and were uneventful. Length of recovery, defined as the interval between the end of the procedure and animal release, was short (6.3±2.8 min), and well below reported lengths of recovery using injectable anesthetics (≥70 min). As compared to open drop administration of isoflurane described in previous studies, the use of an anesthesia machine prevents the risk of potential fatal anesthetic overdose. We conclude that among anesthesia techniques currently available, isoflurane with oxygen as a gas carrier is a safe and useful field anesthetic in martens, when issues with equipment portability can be overcome.

Diabetes mellitus in a nanday conure (Nandayus nenday).

ABSTRACT A 3-year-old male nanday conure (Nandayus nenday) was presented with acute lethargy, polyuria, and polydipsia. Marked persistent hyperglycemia, glycosuria, and ketonuria were also noted. The serum insulin concentration (<3 μU/ml) was lower than reference ranges described for other psittacine birds. Initial treatment included insulin, antibiotics, and supportive care. Insulin therapy was adjusted based on results of serial blood glucose curves. Histopathologic examination of pancreatic biopsy samples revealed normal exocrine pancreatic tissue with rare lymphoplasmocytic infiltrates and absence of pancreatic islets, suggesting atrophy of endocrine pancreatic tissue. Resolution of clinical signs and a normalized blood glucose curve were obtained after administration of long-acting insulin (0.3 IU/kg IM am and 0.25 IU/kg IM pm). One month after initial presentation, the conure was admitted for severe dyspnea and lethargy and died despite supportive care. Histopathologic examination of the pancreas revealed nearly total depletion of the endocrine pancreas with moderate lymphoplasmocytic pancreatitis. Immunohistochemical evaluation of the remaining pancreatic islets was negative for the presence of insulin and positive for glucagon. Results of polymerase chain reaction tests for Chlamydophila psittaci performed on tissues from the liver, spleen, and lung were negative. Transmission electron microscopy did not demonstrate viruses. Clinical and pathological findings observed in this case are consistent with insulin-dependant type 1 diabetes.

Evaluation of a fracture pain model in domestic pigeons (Columba livia)

OBJECTIVE To validate a model of postfracture pain in perching birds. ANIMALS 21 adult domestic pigeons (Columba livia). PROCEDURES In each bird, a standardized osteotomy of 1 femur was performed and the fracture was immobilized with an intramedullary pin. Degree of postoperative pain was evaluated 6 times/d for 4 days by use of 3 methods: an electronic perch for assessment of weight-bearing load differential of the pelvic limbs, 4 numeric rating pain scales for assessment of pain (all of which involved the observer in the same room as the bird), and analysis of video-recorded (observer absent) partial ethograms for bird activity and posture. Measurements obtained were compared with data collected before the surgery to evaluate the ability of these methods to detect pain. RESULTS The weight-bearing load differential was a sensitive, specific, reliable, and indirect measure of fracture-associated pain in the model used. Two of 4 tested pain scales (fractured limb position and subjective evaluation of degree of pain) were sensitive and specific for detecting pain and were reliable in a research setting. Interobserver reliability of the 4 pain scales was excellent. Partial ethograms were sensitive for identifying pain-associated behavior in pigeons, particularly during the first 2 days after surgery. CONCLUSIONS AND CLINICAL RELEVANCE The fracture pain model was reliable and reproducible and may be useful for experimental studies involving postsurgical pain in pigeons. Weight-bearing load differential was the most sensitive and specific means of determining degree of pain in pigeons during the first 4 days after hind limb fracture induction.

DETECTION AND CHARACTERIZATION OF A TRICHOMONAS ISOLATE FROM A REHABILITATED BALD EAGLE (HALIAEETUS LEUCOCEPHALUS)

A hatching-year bald eagle (Haliaeetus leucocephalus) was presented for clinical examination after being found unable to fly. Upon admission, routine wet-mount microscopy detected no trichomonads. Five months later, oral cavity inspection found no abnormalities, but the eagle was swabbed for research on trichomonosis in maritime birds. The swab was used to inoculate an InPouch TF culture and trichomonads were visible within 24 hr. Genotyping (ITS) revealed a Trichomonas isolate that was 100% identical to an isolate from a bearded vulture (Gypaetus barbatus) from the Czech Republic. The eagle was treated with metronidazole (50 mg/kg q 12h PO for 5 consecutive days). Following treatment, the eagle was swabbed and the inoculated InPouch TF culture was monitored daily for 1 wk. No trichomonads were observed. Rehabilitation centers interested in surveillance should consider combining the InPouch TF technique with clinical inspection of live birds to confirm trichomonosis and for future research.

The Value of Endoscopy in a Wildlife Raptor Service

Although endoscopy is part of the basic standard of care in most avian practices, many wildlife rehabilitation centers do not have access to the equipment or do not use it on a regular basis. Endoscopic equipment is easily available at a lower cost on the used market or can be acquired through donations from local human hospitals. Several medical conditions encountered in wild raptors have an improved prognosis if they are diagnosed or treated early with the aid of endoscopy. In many cases, endoscopy provides a noninvasive alternative to exploratory surgery, saving cost and time and decreasing postoperative pain.

Malignant Mixed Chromatophoroma with Cutaneous, Pulmonary, and Testicular Metastases in a Veiled Chameleon (Chamaeleo calyptratus)

Abstract A 6-year-old male veiled chameleon (Chamaeleo calyptratus) was presented for mass removal on the right mandible. Histopathology revealed an iridophoroma, a subclassification of chromatophoromas. Several months later the chameleon was euthanized and the necropsy, combined with histopathology, indicated metastasis of a mixed chromatophoroma within the skin and to the lungs and testicle. The tumor was further subclassified as a mixed iridophoroma and xanthophoroma based on ultrastructure. Other pathologic findings included marked hepatic fibrosis and severe biliary hyperplasia and severe bilateral cystic glomerulopathy. This case demonstrates the malignant potential of chromatophoromas in chameleons and highlights the need for ultrastructural examination of these tumors for proper subclassification.

Surgical Repair of Acquired Ankyloblepharon in a Cockatiel (Nymphicus hollandicus)

ABSTRACT Eyelid anomalies caused by congenital or acquired etiologies occur in birds. A cockatiel (Nymphicus hollandicus) was presented for evaluation of fused eyelids on the right side and a narrowed palpebral fissure on the left side after a burn accident. The right eyelids were reconstructed, and the left palpebral fissure was lengthened by using microsurgical techniques. The cockatiel regained a normal appearance after surgery, and corneal disease was prevented.

ABSOLUTE POLYCYTHEMIA IN A BALD EAGLE (HALIAEETUS LEUCOCEPHALUS)

Abstract:  An approximately 6-mo-old female bald eagle (Haliaeetus leucocephalus) was presented for an inability to fly and bilateral drooped wings. Pectoral muscle atrophy with a moderate polycythemia was present. Over the course of 3 wk, there were no improvements in flight capacity, although the bird gained substantial weight. Further investigation revealed a prominent cyanosis that was responsive to oxygen therapy, a chronic respiratory acidosis with hypoxia, a cardiac murmur, and a persistent polycythemia. No obvious antemortem etiology for the clinical findings was discovered on computerized tomography, angiography, or echocardiography. The bird was euthanatized as a result of the poor prognosis. Necropsy and histopathology revealed no significant cardiovascular or pulmonary pathology. No myopathy was evident on electron microscopy of formalin-fixed tissues. Based on these diagnostics, a neuromuscular disorder is suspected as the cause for the blood gas abnormalities, with a resulting polycythemia from the hypoxia.