Emergency care of raptors

Evaluation of Thermal Antinociceptive Effects of Intramuscular Hydromorphone Hydrochloride in Great Horned Owls (Bubo virginianus)

Across the Americas, great horned owls (Bubo virginianus) are often presented to veterinarians for conditions requiring pain management. Although recent studies have evaluated opioid drugs in raptor species, information in Strigiformes is lacking. The objective of this study was to evaluate the analgesic effect and duration of action of hydromorphone hydrochloride, a full µ-opioid receptor agonist, in great horned owls. In a randomized, blinded, balanced crossover study, 6 adult birds (5 females and 1 male) received hydromorphone (0.3 and 0.6 mg/kg) or saline (0.9% NaCl) solution (0.03 mL/kg; control) in the left pectoral muscle, with a 7-day washout interval between treatments. Each bird was assigned an agitation-sedation score, and the thermal foot withdrawal threshold (TFWT) was measured at predetermined times before (t = 0 hours) and after treatment administration (t = 0.5, 1.5, 3, and 6 hours). Measurements of the TFWT were obtained with a test box equipped with a thermal perch, which delivered a gradually increasing temperature 40-62°C (104-143.6°F) to the right plantar surface of the owl's foot. Compared with controls, hydromorphone at 0.3 mg/kg dose resulted in significantly higher mean TFWT at 0.5 hours (P < 0.001), 1.5 hours (P = 0.003), and 3 hours (P = 0.005), whereas the 0.6 mg/kg dose resulted in significantly higher mean TFWT from 0.5 hours (P = 0.035) to 1.5 hours (P = 0.001). Both hydromorphone doses were associated with a significant change in the agitation-sedation score (P = 0.001), consistent with mild to moderate sedation. Two owls were observed tremoring after administration of the 0.6 mg/kg dose, which was not noted after the 0.5-hour timepoint; no other adverse effects were identified. This study offers scientific evidence to support the use of a µ-opioid agonist in great horned owls for pain management. Pharmacokinetics and other pharmacodynamic studies of other pain models evaluating hydromorphone and other opioid drugs in this species are still needed.

Chlamydia buteonis in birds of prey presented to California wildlife rehabilitation facilities

Chlamydial infections, caused by a group of obligate, intracellular, gram-negative bacteria, have health implications for animals and humans. Due to their highly infectious nature and zoonotic potential, staff at wildlife rehabilitation centers should be educated on the clinical manifestations, prevalence, and risk factors associated with Chlamydia spp. infections in raptors. The objectives of this study were to document the prevalence of chlamydial DNA shedding and anti-chlamydial antibodies in raptors admitted to five wildlife rehabilitation centers in California over a one-year period. Chlamydial prevalence was estimated in raptors for each center and potential risk factors associated with infection were evaluated, including location, species, season, and age class. Plasma samples and conjunctiva/choana/cloaca swabs were collected for serology and qPCR from a subset of 263 birds of prey, representing 18 species. Serologic assays identified both anti-C. buteonis IgM and anti-chlamydial IgY antibodies. Chlamydial DNA and anti-chlamydial antibodies were detected in 4.18% (11/263) and 3.14% (6/191) of patients, respectively. Chamydial DNA was identified in raptors from the families Accipitridae and Strigidae while anti-C.buteonis IgM was identified in birds identified in Accipitridae, Falconidae, Strigidae, and Cathartidae. Two of the chlamydial DNA positive birds (one Swainson’s hawk (Buteo swainsoni) and one red-tailed hawk (Buteo jamaicensis)) were necropsied, and tissues were collected for culture. Sequencing of the cultured elementary bodies revealed a chlamydial DNA sequence with 99.97% average nucleotide identity to the recently described Chlamydia buteonis. Spatial clusters of seropositive raptors and raptors positive for chlamydial DNA were detected in northern California. Infections were most prevalent during the winter season. Furthermore, while the proportion of raptors testing positive for chlamydial DNA was similar across age classes, seroprevalence was highest in adults. This study questions the current knowledge on C. buteonis host range and highlights the importance of further studies to evaluate the diversity and epidemiology of Chlamydia spp. infecting raptor populations.

Pharmacokinetic Behaviour of Enrofloxacin after Single Intramuscular Dosage in American Black Vultures (Coragyps atratus)

The aim of the study was to investigate the intramuscular pharmacokinetics of enrofloxacin in black vultures (Coragyps atratus). The pharmacokinetics of a single intramuscular dose (10 mg/kg) of enrofloxacin was studied in six vultures. Plasma concentrations of enrofloxacin and its active metabolite, ciprofloxacin, were determined by high-performance liquid chromatography (HPLCuv). Pharmacokinetic parameters were estimated using non-compartmental and compartmental analysis. After intramuscular administration, enrofloxacin showed a rapid and complete absorption, reaching a Cmax value of 3.26 ± 0.23 μg/mL at 1.75 ± 0.53 h. A long terminal half-life of 19.58 h has been observed. Using previously published MIC values to perform a PK/PD analysis, cumulative fraction responses obtained after Monte Carlo simulation for AUC/MIC > 30, 50 and 125 were 72.93%, 72.34% and 30.86% for E. coli and 89.29%, 88.89% and 58.57% for Mycoplasma synoviae, respectively. Cumulative fraction responses obtained for Cmax/MIC index were 33.93% and 40.18% for E. coli and M. synoviae, respectively. The intramuscular administration of 10 mg/kg could be appropriate to treat infectious diseases caused by gram-positive bacteria with MIC value lower than 1 µg/mL; however, although enrofloxacin showed a slow elimination in black vultures, plasma concentrations were insufficient to reach the gram-negative stablished breakpoints.

Ophthalmic Evaluation of Raptors Suffering From Ocular Trauma

Ocular problems are often associated with traumatic injury in raptors. A comprehensive evaluation, including a complete ophthalmic examination, is vital in determining the patient's overall health and suitability for release. Steps for conducting ocular examination and diagnostic testing in raptors is discussed. Additionally, common clinical findings after trauma, as well as the mechanisms by which ocular injury occurs, are outlined. An overview of medical treatments recommended for commonly diagnosed ocular diseases and the utility of ancillary diagnostic procedures is also presented.

Fecal Sample Collection Method for Wild Birds-Associated Microbiome Research: Perspectives for Wildlife Studies

Simple Summary

This paper describes an easy-to-build box for the noninvasive collection of feces from wild birds or small wild animals (up to 1 kg), including a plastic storage box, a plastic tray, and a vinyl-coated hardware cloth. This method could minimize potential contamination and allow for cross-study comparisons on gut microbiomes for wildlife medicine, conservation, ecology, and evolutionary biology.

Abstract

Gut microbial communities play important roles in host health, modulating development, nutrient acquisition, immune and metabolic regulation, behavior and diseases. Wildlife microbiome studies and host–microbe interaction and exploration might be an important goal for evolutionary biology, conservation, and ecology. Therefore, collection and sampling methods must be considered before choosing a microbiome-based research plan. Since the fecal microbial community reflects the true gut community better than that of cloacal swab samples and only few nondestructive methods have been described, we propose an easy-to-build box for a noninvasive fecal collection method. The main components of the collection box include a plastic storage box, a plastic tray, a vinyl-coated hardware cloth, and a 10% bleach solution. In the plastic box, the tray is positioned under the raised grate, where the bird is placed, to reduce the risk of contamination of the fecal samples. This procedure could simplify handling and processing phases in wild birds or other animals. It might represent a cheap and useful method for research studies, wildlife rescue center activities, veterinary practices, and conservation practitioners.

Distraction Osteogenesis in Two Wild Raptors

Distraction osteogenesis was used in 2 wild raptor patients for the repair of tibiotarsal fractures. The first case was a hatching year female peregrine falcon (Falco peregrinus) admitted with an open oblique right distal tibiotarsal fracture. The fracture was surgically managed with the external skeletal fixator intramedullary pin tie-in technique (ESF-IM pin tie-in). Appropriate healing of the fracture site occurred with the ESF-IM pin tie-in. However, there was significant pelvic limb shortening of the affected leg, and the bird consequently developed pododermatitis on the contralateral foot. The second case was an adult female great horned owl (Bubo virginianus) that was admitted with a closed, partially healed, overriding right tibiotarsal fracture. Because of the advanced stage of this fracture, which presented with a fibrous callus, and the already apparent pelvic limb shortening, the ESF-IM pin tie-in was not used. Both patients were fitted with a circular external skeletal fixator (CESF), and distraction osteogenesis was performed until the length of the pelvic limb was deemed anatomically adequate. It is critical that rehabilitated raptors be released without any physical conditions that may reduce their ability to survive and reproduce in the wild. Pelvic limb shortening can potentially predispose a raptor patient to pododermatitis, even with fatal consequences, in both captive and wild environments. The orthopedic technique used here proved useful to repair the limb shortening in both raptor cases, and each bird fully recovered and was released.

Ambulatory Emergency Medicine

While practicing exotic animal medicine as an ambulatory practitioner, veterinarians need to be prepared for the inevitable emergency call. Emergencies in exotic animal medicine come in all shapes and sizes and the veterinarian must be prepared for a variety of situations. With the proper training, equipment, and managing client expectations, an ambulatory exotics animal practitioner can successfully address emergencies. This article provides a brief overview in managing emergency cases in an ambulatory exotics animal practice.

Outcomes of Conservatively Managed Coracoid Fractures in Wild Birds in the United Kingdom

Coracoid fractures are a frequent presentation in wild birds, commonly caused by collisions with motor vehicles, windows, or other obstacles such as pylons. Despite this, there are few reports of outcomes, and those published consist of small numbers of birds with conflicting results when comparing conservative management with surgical intervention. To determine outcome success of conservative management in a larger population of wild birds, records of 232 adult wild birds in the United Kingdom (UK) with closed unilateral coracoid fractures confirmed on radiography and surviving more than 48 hours after admission were retrospectively analyzed. Conservative management had a high success rate, with 75% (n = 174/232; 95% confidence limits [CL]: 69%, 80%) of all birds successfully released back to the wild. The proportion of raptors successfully returned to the wild was even higher at 97% (n = 34/35; 95% CL: 85%, 99%). A significant difference of 26% (95% CL: 18%, 34%, Fisher exact test, P < .001) was demonstrated when comparing the outcome success of raptors (97%, n = 34/35) to nonraptors (71%, n = 140/198). The median time in captive care until released back to the wild was 30 days (95% CL: 27, 33). Conservative management of coracoid fractures in wild birds in the UK, and in particular in raptors, appears to result in good outcomes. The approach is low cost and noninvasive, in contrast to surgery, and is recommended as the first-line approach of choice in these cases.

Second-generation Anticoagulant Rodenticide Poisoning in a Captive Andean Condor (Vultur gryphus)

A 28-year-old female Andean condor (Vultur gryphus) housed in an outside exhibit at the National Aviary in Pittsburgh, PA, began showing signs of weakness. Toxicosis with an anticoagulant rodenticide was suspected because its mate had died 1 day earlier from possible brodifacoum poisoning. A rapid decline in the packed cell volume, despite vitamin K₁ treatment, necessitated a blood transfusion with blood from bald eagles (Haliaeetus leucocephalus) and Steller's sea eagles (Haliaeetus pelagicus). Supportive therapy after transfusion included vitamin K₁ (5 mg/kg IM q12h) as well as enrofloxacin, vitamin B complex, selenium and vitamin E, and subcutaneous fluids as needed. After a 39-day treatment period, a tapering dosage of vitamin K₁ was initiated, and treatment ended after 17 weeks. However, 2 weeks later, the bird suffered from a potential relapse. It was successfully treated with a repeat tapering vitamin K₁ regimen lasting a total of 4 months.

Emergencies and Critical Care of Commonly Kept Fowl

Fowl are birds belonging to one of the 2 biological orders, the game fowl or land fowl (Galliformes) and the waterfowl (Anseriformes). Studies of anatomic and molecular similarities suggest these two groups are close evolutionary relatives. Multiple fowl species have a long history of domestication. Fowl are considered food-producing animals in most countries and clinicians should follow legislation regarding reportable diseases and antibiotic use, even if they are pets. This article reviews aspects of emergency care for most commonly kept fowl, including triage, patient assessment, diagnostic procedures, supportive care, short-term hospitalization, and common emergency presentations.

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.

Coracoid fractures in wild birds: a comparison of surgical repair versus conservative treatment

Medical records of wild bird admissions to the Australian Wildlife Health Centre at Healesville Sanctuary were analyzed for cases of unilateral coracoid fractures with known final outcomes. Forty-seven birds, comprising 13 species, fit these criteria. Of those birds, 18 were treated conservatively with analgesia and cage rest without coaptation bandaging, and 29 were treated with surgical correction of the fracture. Of the conservatively managed birds, 89% (16 of 18) were released back into the wild. Conversely, 34% (10 of 29) of the surgically managed birds were released. Treatment success for release differed significantly between treatment groups (P < .001). Intraoperative death from concurrent trauma was the major reason that surgically treated birds were not released. Given the high risks associated with surgical treatment and the high success rate of conservative management, cage rest without surgery appears prudent when managing coracoid injuries in birds.