Highly Pathogenic Avian Influenza A(H5N1) Virus Clade 2.3.4.4b Infections in Wild Terrestrial Mammals, United States, 2022.

We describe the pathology of natural infection with highly pathogenic avian influenza A(H5N1) virus of Eurasian lineage Goose/Guangdong clade 2.3.4.4b in 67 wild terrestrial mammals throughout the United States during April 1‒July 21, 2022. Affected mammals include 50 red foxes (Vulpes vulpes), 6 striped skunks (Mephitis mephitis), 4 raccoons (Procyon lotor), 2 bobcats (Lynx rufus), 2 Virginia opossums (Didelphis virginiana), 1 coyote (Canis latrans), 1 fisher (Pekania pennanti), and 1 gray fox (Urocyon cinereoargenteus). Infected mammals showed primarily neurologic signs. Necrotizing meningoencephalitis, interstitial pneumonia, and myocardial necrosis were the most common lesions; however, species variations in lesion distribution were observed. Genotype analysis of sequences from 48 animals indicates that these cases represent spillover infections from wild birds.

FACTORS IMPACTING SUCCESSFUL REHABILITATION OF BIG BROWN BATS (EPTESICUS FUSCUS) IN A WISCONSIN WILDLIFE REHABILITATION CENTER: A 5-YEAR RETROSPECTIVE.

The big brown bat (Eptesicus fuscus; EPFU) is widely distributed throughout the Americas and plays critical roles in sustaining cave ecosystems and abating agricultural pests. In Wisconsin, EPFU is a threatened species with declining populations due to hibernacula disturbances, wind turbines, and habitat destruction. Due to their ecological and economic value, it is important to be able to release EPFU that enter wildlife rehabilitation centers back to the wild. This study evaluated the medical records of 454 EPFU (275 male, 179 female) admitted to a wildlife rehabilitation center in Wisconsin from 2015 to 2020. For each bat, the season at intake, examination findings, length of time in rehabilitation, and final outcome (released or not released) were recorded. Using a multiple variable logistic regression model, there was a statistically significant positive association between length of time in the rehabilitation center and likelihood of release (odds ratio [OR] 1.08; 95% CI 1.06-1.12); this association can be explained by the need to overwinter some otherwise healthy bats in rehabilitation during hibernation. The following examination findings were associated with a significantly lower likelihood of release: wing injury (OR 0.32; 95% CI 0.10-0.89) and decreased body condition (OR 0.29; 95% CI 0.12-0.64). When corrected for time spent in rehabilitation (potentially artificially lengthened due to hibernation), patients admitted in the summer and fall were less likely to be released than those admitted in the winter (OR 0.93; 95% CI 0.90-0.96 and OR 0.95; 95% CI 0.92-0.97, respectively). The results of this study can be used to help veterinarians and licensed rehabilitators better triage EPFU during admission to wildlife rehabilitation centers in order to improve management and promote successful release back to the wild.

Application of Stable Isotopic Ratio Analysis to Identify the Cause of Acute Versus Chronic Lead Poisoning of a Tundra Swan (Cygnus columbianus): A Case Study.

We utilized lead (Pb) stable isotopes to identify the source of acute Pb poisoning in a Tundra Swan (Cygnus columbianus) and evaluated overall Pb exposure. Upon necropsy, we obtained samples of blood, liver, kidney, heart, thigh, breast, femur, and metallic objects (i.e., fishing sinker, spring and swivels) from the gizzard for Pb isotopic analysis. Pb isotope ratios of blood and soft tissues were essentially identical to the Pb ratios of the sinker, the likely source of acute poisoning. The spring and swivels had lower Pb content and ratios distinct from tissue, suggesting no significant contribution to poisoning. Femur Pb isotopic composition was the most distinct biological sample and indicative of a combination of sources. These results demonstrate isotopic analysis as a viable method for determining the source of acute Pb poisoning, and that Pb isotope ratios in bone most likely record a lifetime-averaged metric of Pb exposure.

Successful outcome of shell fractures in freshwater turtles treated with plate or screws and wire fixation techniques: 51 cases (2014-2019).

OBJECTIVE: To evaluate the outcome of surgical fixation of shell fractures in rehabilitated wild freshwater turtles. ANIMALS: 51 freshwater turtles with 86 shell fractures. PROCEDURES: The medical record database of a wildlife rehabilitation center in Wisconsin was searched from 2014 through 2019 for records of freshwater turtles with shell fractures repaired with a plate technique, screws and wire technique, or both. Signalment, fracture location, therapeutic approach (including the type of hardware used for repair), dry-docking duration, time to hardware removal, postremoval care, and outcome were evaluated. RESULTS: 36 of 51 (71%) turtles with shell fractures experienced successful fracture healing following surgical hardware fixation, and 33 (65%) were released. Shells of 38 (75%) turtles were repaired with plates only, 5 (10%) turtles with wire only, and 8 (16%) turtles with a combination of plates and screws and wires. Of the 51 turtles, 13 (25%) did not survive > 4 weeks following hardware repair, leaving 38 animals available to assess fracture healing. Median time to start staged removal was 42 days (range, 35 to 49 days) and to complete removal of the applied hardware was 56 days (range, 26 to 77 days). Complications associated with placement of the hardware occurred in 6 of 38 (16%) turtles. Complications included screw hole infection (4/38 [11%]), fracture necrosis (1/38 [3%]), and deep screw hole penetration (1/38 [3%]). CLINICAL RELEVANCE: Results indicated that shell fractures in freshwater turtles treated with surgical fixation techniques had a successful outcome. Most complications were minor, and fractures improved with time, resulting in acceptable fracture healing for release.