In Africa, humans and large carnivores compete over access to resources, including prey. Disturbance by humans to kills made by carnivores, often for purposes of obtaining all or portions of the carcass, constitutes a form of human-wildlife conflict. However the occurrence of this practice, known as human kleptoparasitism, and its impact on carnivores has received little scientific attention. We obtained expert opinions from African lion researchers and stakeholders via a standardized questionnaire to characterize the geographic extent and frequency of human kleptoparasitism as it occurs in modern times. Our survey found modern human kleptoparasitism on kills made by lions, and possibly other large carnivores in Africa, to be geographically more widespread than previously reported. Meat lost to humans requires carnivores to hunt and kill additional prey thereby causing stress, increasing their energetic costs and risks of natural injury, and exposing them to risk of direct injury or death from human usurpers. Because of their conspicuous behaviors and tendency towards killing large-bodied prey, lions are particularly susceptible to humans detecting their kills. While human kleptoparasitism was geographically widespread, socio-economic factors influenced the frequency of occurrence. Prey type (wild game or domestic livestock) influenced human attitudes towards meat theft; ownership allows for legal recovery of livestock carcasses, while possessing wild game meat is mostly illegal and may incur penalties. Meat theft was associated with other illegal activities (i.e., illegal mining) and most prevalent among people of low income, including underpaid game scouts. Despite quantifiable costs to carnivores of human disturbance to their kills, the majority of experts surveyed reported a lack of knowledge on this practice. We propose that human disturbance at kills, especially loss of prey through human kleptoparasitism, constitutes an important anthropogenic threat that may seriously impact energy budgets of individual lions and other scavengers when meat and carcasses are removed from the ecosystem, and that the costs incurred by carnivores warrants further investigation.

There is a growing interest in social behavior change with age,1,2,3,4,5 and the impacts of sociality on longevity,6,7,8 but current knowledge is broadly limited to primates, societies structured by dominance hierarchies, or single-sex studies. It is less clear how social aging patterns emerge in carnivores. The African lion (Panthera leo), a species that lives in egalitarian fission-fusion societies, presents an exceptional opportunity to examine social aging. Across felids, lions are unique in their dependence on conspecifics for many essential processes,9,10,11 and there is vast knowledge of lion behavioral ecology,10,11,12,13,14 including documented reproductive senescence in both sexes.14,15 Applying spatial-social network analyses across 30 years of data on the wild Serengeti lion population, we show that sex strongly modulates patterns of social aging and longevity. Group size increased with age for both sexes, but only males experienced significant changes in associate numbers (degree), specifically to females, which peaked in mid-life before declining. While aging females experienced declines in intra-sex connectivity (strength) and bond strength (mean strength), they peaked in both to males during mid-life. Male inter-sex strength also peaked in mid-life, while conversely their intra-sex strength and mean strength significantly dipped in mid-life. Although social associations were important for survival in both sexes, the investment diverged significantly: females\' overall network connectivity was key for longevity, while the number of associates was important for males. These findings illustrate important potential effects of social aging in a wild carnivore and demonstrate how these diverge strongly between the sexes.

Laparoscopic ovariectomy under general anesthesia was planned in a 10-year-old, 146 kg, apparently healthy female African lion (Panthera leo). The lion was immobilized via intramuscular darts containing midazolam (0.033 mg/kg), medetomidine (50 µg/kg) and ketamine (2.5 mg/kg), and intubated using an endotracheal tube (16 mm internal diameter). The anesthesia was maintained using sevoflurane (0.9-2.1% end-tidal concentration), in combination with remifentanil (0.1 µg/kg/min) and ketamine (11 µg/kg/min) at a constant rate infusion (CRI), with Hartmann\'s solution (5 mL/kg/hr). Surgery was conducted with stable vital signs, but hypotension (mean arterial blood pressure 55 mmHg) developed, requiring dobutamine treatment. The hypotension was effectively controlled by adjusting dobutamine from 5 µg/kg/min to 0.2 to 0.3 µg/kg/min. This case suggests possibilities that dosages in this range can be clinically useful for peri-anesthetic hypotension in lions.

OBJECTIVE: Canine extraction of large carnivores can pose significant risk due to extensive tissue damage during aggressive bone reduction. This report highlights a rare instance in which the use of a piezoelectric surgical unit (PSU) for maxillary canine extraction in a large carnivore resulted in successful outcomes with minimal tissue damage.
METHODS: A 10-year-old male African lion presented with decreased appetite because of bilateral maxillary canine fractures. Intraoral radiographs revealed enlarged root canals and periapical radiolucency of the fractured canines, leading to a diagnosis of periapical periodontitis and pulpitis. To extract the right maxillary canine, conventional method using hand instrument failed to achieve adequate luxation, necessitating the use of the flat blade of the PSU to sever the periodontal ligament. The left maxillary canine was extracted using PSU from the beginning, and the extraction time was markedly shortened by using PSU without additional alveolar bone damage or bleeding.
CONCLUSIONS: This case demonstrated that utilizing PSU for canine extraction in a lion resulted in periodontal ligament separation, reducing damage to the alveolar bone and shortening surgical time. It suggests the promising application of PSU in tooth extraction for large wild animals, indicating its potential significance in veterinary dentistry.

OBJECTIVE: We conducted a One Health investigation to assess the source and transmission dynamics of SARS-CoV-2 infection in African lions (Panthera leo) at Utah\'s Hogle Zoo in Salt Lake City from October 2021 to February 2022.
RESULTS: Following observation of respiratory illness in the lions, zoo staff collected pooled faecal samples and individual nasal swabs from four lions. All specimens tested positive for SARS-CoV-2 by reverse transcription-polymerase chain reaction (RT-PCR). The resulting investigation included: lion observation; RT-PCR testing of lion faeces every 1-7 days; RT-PCR testing of lion respiratory specimens every 2-3 weeks; staff interviews and RT-PCR testing; whole-genome sequencing of viruses from lions and staff; and comparison with existing SARS-CoV-2 human community surveillance sequences. In addition to all five lions, three staff displayed respiratory symptoms. All lions recovered and no hospitalizations or deaths were reported among staff. Three staff reported close contact with the lions in the 10 days before lion illness onset, one of whom developed symptoms and tested positive for SARS-CoV-2 on days 3 and 4, respectively, after lion illness onset. The other two did not report symptoms or test positive. Two staff who did not have close contact with the lions were symptomatic and tested positive on days 5 and 8, respectively, after lion illness onset. We detected SARS-CoV-2 RNA in lion faeces for 33 days and in lion respiratory specimens for 14 weeks after illness onset. The viruses from lions were genetically highly related to those from staff and two contemporaneous surveillance specimens from Salt Lake County; all were delta variants (AY.44).
CONCLUSIONS: We did not determine the sources of these infections, although human-to-lion transmission likely occurred. The observed period of respiratory shedding was longer than in previously documented SARS-CoV-2 infections in large felids, indicating the need to further assess duration and potential implications of shedding.

Lions (Panthera leo) play a crucial ecological role in shaping and maintaining fragile ecosystems within Africa. Conservation efforts should focus on genetic variability within wild populations when considering reintroduction attempts. We studied two groups of lions from two conservation sites located in Zambia and Zimbabwe to determine their genetic make-up, information that is usually unknown to the sites. In this study, we analysed 17 specimens for cytb and seven microsatellite markers to ascertain family relationships and genetic diversity previously obtained by observational studies. We then produced a standardised haplogroup phylogeny using all available entire mitogenomes, as well as calculating a revised molecular clock. The modern lion lineage diverged ~151 kya and was divided into two subspecies, both containing three distinct haplogroups. We confirm that Panthera leo persica is not a subspecies, but rather a haplogroup of the northern P.l. leo that exited Africa at least ~31 kya. The progenitor to all lions existed ~1.2 Mya, possibly in SE Africa, and later exited Africa and split into the two cave lion lineages ~175 kya. Species demography is correlated to major climactic events. We now have a detailed phylogeny of lion evolution and an idea of their conservation status given the threat of climate change.

The Amur tiger is currently confronted with challenges of anthropogenic development, leading to its population becoming fragmented into two geographically isolated groups: smaller and larger ones. Small and isolated populations frequently face a greater extinction risk, yet the small tiger population\'s genetic status and survival potential have not been assessed. Here, a total of 210 samples of suspected Amur tiger feces were collected from this small population, and the genetic background and population survival potentials were assessed by using 14 microsatellite loci. Our results demonstrated that the mean number of alleles in all loci was 3.7 and expected heterozygosity was 0.6, indicating a comparatively lower level of population genetic diversity compared to previously reported studies on other subspecies. The genetic estimates of effective population size (Ne) and the Ne/N ratio were merely 7.6 and 0.152, respectively, representing lower values in comparison to the Amur tiger population in Sikhote-Alin (the larger group). However, multiple methods have indicated the possibility of genetic divergence within our isolated population under study. Meanwhile, the maximum kinship recorded was 0.441, and the mean inbreeding coefficient stood at 0.0868, both of which are higher than those observed in other endangered species, such as the African lion and the grey wolf. Additionally, we have identified a significant risk of future extinction if the lethal equivalents were to reach 6.26, which is higher than that of other large carnivores. Further, our simulation results indicated that an increase in the number of breeding females would enhance the prospects of this population. In summary, our findings provide a critical theoretical basis for further bailout strategies concerning Amur tigers.

Neoplasia is one of the main causes of euthanasia in geriatric captive nondomestic felids. However, few studies have examined oral tumors in these animals. We describe here the clinicopathologic features of gingival squamous cell carcinoma (SCC) in 2 lions (Panthera leo) from separate zoologic collections. In both cases, the lions had a history of sialorrhea, bloody oral discharge, and anorexia. Autopsy findings in both lions were similar and were characterized by poorly circumscribed, friable, and bloody gingival masses with grossly apparent invasion of the mandibular bone; a pathologic fracture was observed in 1 case. Histologically, the masses consisted of poorly circumscribed, unencapsulated, densely cellular proliferations of neoplastic epithelial cells arranged in irregular islands, cords, and anastomosing trabeculae with formation of keratin pearls, which, coupled with positive immunohistochemistry for pancytokeratin, were diagnostic for SCC. Although no metastases were found in either animal, both lions were ultimately euthanized because of poor prognosis.

Two female (FL 1, FL 2) and one male (ML) 11-wk-old, intact, captive African lion cubs (Panthera leo leo) were presented with a history of mild vestibular signs. Initial serum vitamin A concentrations were low (140 nmol/L) for ML. Calvarial hyperostosis was confirmed using computed tomography (CT) of the head and cervical vertebrae in each cub. CT measurements were adapted in relation to the skull width. ML showed the most pronounced thickening of the tentorium cerebelli and occipital bone, represented by a tentorium cerebelli to skull width ratio (TCR) of 0.08 (FL 1: 0.06, FL 2: 0.05) and a basisphenoid to skull width ratio (BBR) of 0.07 (FL 1: 0.06, FL 2: 0.04). Magnetic resonance imaging (MRI) revealed cerebellar herniation and cervical intramedullary T2-weighted hyperintensity from C1, extending caudally for at least two cervical vertebrae in all cubs. Treatment was initiated with subcutaneous vitamin A supplementation and feeding of whole carcasses. Improvement in ataxia was noticed 3 wk later. Follow-up CT and MRI examinations were performed in ML after 3 and 8 mon. The affected bones appeared slightly less thickened and TCR and BBR had decreased to 0.05 after 3 mon. The cerebellum remained mildly herniated, accompanied by amelioration of cervical T2w hyperintensities. After 8 mon, evaluation and diagnostic imaging revealed further improvement regarding the neurologic status and measurements (TCR 0.05, BBR 0.04) despite persistence of a subtle cerebellar herniation. In conclusion, bone remodeling and improvement in clinical signs may be achievable in young lion cubs presented with calvarial hyperostosis and may be attributable to high-dose vitamin A supplementation.

Based upon previous clinical experience with domestic cats (Felis catus), the ability to assess ABC blood types and blood (in-)compatibilities of nondomestic felids, and adequately consider and plan for blood transfusions, may be important. Although nondomestic felids appear to have an ABC blood group system similar to domestic cats, typing with point-of-care kits and by CMAH genotyping for domestic cats have not been reported. In this study, 162 blood samples from 18 different nondomestic felid species (cheetah [Acinonyx jubatus, n = 42], lion [Panthera leo, n = 33], tiger [Panthera tigris, n = 23], Canada lynx [Lynx canadensis, n = 11], snow leopard [Uncia uncia, n = 10], puma [Puma concolor, n = 7], clouded leopard [Neofelis nebulosa, n = 6], serval [Leptailurus serval, n = 5], jaguar [Panthera onca, n = 5], fishing cat [Prionailurus viverrinus, n = 4], Pallas cat [Felis manul, n = 3], bobcat [Lynx rufus, n = 3], ocelot [Leopardus pardalis, n = 3], black footed cat [Felis nigripes, n = 2], leopard [Panthera pardus, n = 2], African wildcat [Felis lybica, n = 1], caracal [Caracal caracal, n = 1], and sand cat [Felis margarita, n = 1]) were ABC blood typed by laboratory and point-of-care tests, genotyped for four known CMAH variants for type B and type C (AB) phenotypes, and crossmatched with one another and domestic type A cats. Traditional tube typing identified blood type A (n = 106), type B (n = 8), type C (n = 43), and no discernible ABC type (n = 4). Several discrepancies were found between point-of-care and traditional typing test results. None of the tested felids possessed the four CMAH variants responsible for type B and C (AB) in domestic cats. Crossmatch incompatibilities (≥2+ agglutination) were identified within and between nondomestic felid species and beyond ABC incompatibilities. Of 26 crossmatches performed between domestic cats and various nondomestic felids, only 7 (27%) were compatible. In conclusion, point-of-care typing kits and CMAH genotyping, successfully used in domestic cats, may not identify the correct ABC blood type in nondomestic felids. Prior crossmatching is recommended to increase the likelihood of compatible transfusions between any nondomestic felids.