Elephant endotheliotropic herpesvirus hemorrhagic disease (EEHV-HD) is an important cause of morbidity and mortality in juvenile Asian (Elephas maximus) and African (Loxodonta africana) elephants in human care. Measures of disease frequency have not been rigorously established for EEHV in any elephant population. The objective of this retrospective descriptive epidemiologic study was to determine period prevalence, cumulative incidence, and incidence rate (IR) for EEHV infection and EEHV-HD in the US elephant population between 2014 and 2024. A case of EEHV infection was defined as an elephant of any age with an episode of EEHV viremia with levels >1,000 viral genome equivalents (vge)/ml, and a case of EEHV-HD was defined as a juvenile elephant with EEHV viremia levels >5,000 vge/ml, along with the presence of clinical signs, blood work abnormalities, or pathologic evidence suggesting vasculopathy. After institutional approval for data transfer, deidentified whole-blood EEHV qPCR results from the National Zoo Elephant Herpesvirus Laboratory were analyzed. The data originated from 30 zoos, encompassing 234 elephants, and included >23,000 PCR reactions. EEHV1A and 3A were the most prevalent and incident EEHV types for Asian and African elephants, respectively. Analyses indicated that if 100 juvenile Asian elephants were monitored over 1 yr, 7.91 new cases of EEHV1A-HD would occur in the United States. Similarly, 4.81 new cases of EEHV3A-HD would be expected to occur if 100 juvenile African elephants were monitored over 1 yr in the United States. EEHV6-HD appears to pose an underreported threat to African elephants with an IR of 1.46/100 elephant years.
Conflict between humans and wildlife in communities living adjacent to protected areas is one of the most intractable issues facing policymakers and conservation practitioners. The presence of wildlife can negatively impact on humans in a number of different ways, from fatalities to loss of livelihoods. Proximity to human communities can also negatively impact wildlife, for example through retaliatory killings and illegal harvesting. Meeting conservation objectives therefore often requires measures to reduce human-wildlife conflict, especially at the borders of national parks. We examine the drivers of human-elephant conflict occurring in villages bordering Kruger National Park (KNP), South Africa - which can result in the killing of elephants that enter these communities. We use data from surveys in these communities, as well as online descriptions of an incident in the village of Matsulu which resulted in the death of an elephant and which was filmed by several community members, generating a large number of social media stories. Social media stories and survey responses both highlighted the same underlying drivers of elephant killings: that members of the community appear to have tampered with the KNP fence and encouraged elephants to exit the park. Community members benefited through obtaining elephant meat. Data from the survey additionally indicated that a small number of community members profit financially from elephant escapes, but that the wider community experiences a range of negative impacts, which may be partially defrayed by benefits in the form of meat. The majority (71.2%) of survey respondents stated they would support non-lethal elephant management approaches. The current policy regarding elephant management in KNP is that elephants are protected within the park but if outside and considered a danger to humans are permitted to be killed. This policy has implications for elephant conservation in a context where members of local communities may feel incentivised to facilitate the escape of elephants, in order to benefit from legitimately killing them. We recommend an evaluation of this policy in the light of community attitudes towards elephants and their management.
Human-elephant conflict causes substantial damages to people and elephants worldwide through crop damage, property loss, injuries and fatalities. As interactions increase, identifying environmental drivers of reported elephant occurrence is essential for developing long-term mitigation strategies. We surveyed 420 community members living in conflict areas across Kerala and Karnataka, in the southern Western Ghats of south India using opportunistic and snowball sampling. We predicted that reported elephant occurrence would be positively associated with higher rainfall, lower human population density, higher years of residence, and suitable land cover, and negatively associated with distance to protected areas and water bodies. We used generalized additive models to estimate the probability of reported elephant occurrence, and a Markov Chain model to project future occurrence in 2030. Our results partially supported these predictions. Reported elephant occurrence increased with more rainfall and was higher when closer to protected areas and water bodies, however, human population density and years of residence showed significant non-linear effects, indicating their influence on reported elephant occurrence is more complex than anticipated. Across both landscapes, relationships between environmental variables and reported elephant occurrence shifted from near-linear in 2022 to non-linear patterns in 2030, indicating growing unpredictability in elephant movement under changing conditions. Thematic analysis of community responses revealed key themes of elephant habitat changes such as: perceived habitat changes and dense forest, increased human-elephant interactions, and mitigation measures. Findings highlight the importance of habitat restoration, maintaining functional ecological corridors, and integrating local knowledge with environmental modeling to better understand conflict and support coexistence.
Anecdotal accounts of inebriated elephants are widespread across elephant-inhabited regions, yet the molecular and mechanistic basis underlying these observations remains incompletely understood. Alcohol metabolism in mammals is primarily mediated by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). We investigated elephant ADH and ALDH at the genomic, transcriptional, and enzymatic levels, comparing them with humans, hamsters, and rats. Elephant liver predominantly expressed three ADH1 genes, as in humans and hamsters that voluntarily consume ethanol, a feature otherwise reported mainly in primates. We measured hepatic ADH and cytosolic ALDH activities in elephants, despite challenges in sample collection. Elephant ADH exhibited high ethanol affinity, allowing enzymatic activity at low substrate concentrations, likely related to large body size. ADH catalytic efficiency was comparable to other species, and cytosolic ALDH showed relatively high efficiency. These results suggest that elephants are less likely to possess exceptionally low hepatic ethanol-metabolizing capacity, although the lack of data on mitochondrial ALDH2 activity should be taken into consideration. Elephants also exhibited unique features, including the absence of ADH4 gene expression, duplication of ALDH1A1, and pseudogenization of ALDH1B1, which appear to have arisen in association with diet and potential functional redundancy among paralogs. In addition to their ecological and evolutionary significance, these findings may contribute to the interpretation of drug metabolism and support evidence-based pharmacological management in elephants, given the role of ADH and ALDH in pharmaceutical metabolism. Together, this study provides a molecular and enzymatic basis for understanding ethanol metabolism in elephants.
Droughts are globally increasing in duration, frequency and intensity, thereby endangering the survival of wildlife species. Understanding how animals behave during drought is essential to develop conservation measures that aid wildlife survival and prevent human-wildlife conflict in a changing climate. Yet, little is known about animal behaviour during drought. Specifically, existing work on animal behaviour and drought typically does not account for the timescale and the intensity of the drought. We use 19 years of GPS data from the African elephant (Loxodonta africana), a species at risk from drought, collected in Southern Africa, where droughts are increasingly common. We study if there is a connection (i) between drought and the amount of space elephants use and (ii) between drought and elephant habitat selection. We examine drought conditions using the Standardized Precipitation-Evapotranspiration Index (SPEI) at a 1-month, a 3-month, and a 12-month timescale. We found that elephants had smaller home ranges and movement distances when their environment became drier at a 1-month timescale. Importantly, SPEI at a 1-month timescale was a better predictor of elephant home range size than precipitation and NDVI, suggesting that drought conditions may affect elephant movement through more ways than a lack of precipitation or vegetation greenness. In addition, we found that elephant habitat selection changed as a function of drought conditions at all three timescales, but the direction of the change often depended on the timescale of the drought. We found that elephants were closer to inland water and in areas with lower human population density during drought at a 1-month timescale, but farther from inland water and in areas with higher human population density when drought lasted longer. Overall, our results show that drought conditions, as measured by SPEI, predict elephant movement behaviour. We stress the importance of (i) using a drought index rather than only precipitation levels to examine drought conditions and (ii) considering the timescale at which drought occurs. These insights could help to better understand how animals behave during drought and to assess the risk of human-wildlife conflict across species, regions and drought timescales.
Biodiversity and ecosystem services (ES) represent two primary focuses in global ecological conservation efforts. Protected area plans that integrate both objectives are generally more effective; however, ES are often neglected by policymakers and protected area managers. In China, nature reserve networks have been established to conserve the habitats of endangered flagship species such as the Asian elephant, in response to habitat loss, fragmentation, and increasing human-elephant conflicts. This study focused on the primary distribution of Asian elephants in Yunnan province, China. We utilized the InVEST model to quantify four ESs (habitat quality, carbon storage, soil retention, and water yield) and the MaxEnt model to assess habitat suitability, identified the spatial distribution and relationship between ES hotspots and suitable habitats for Asian elephants, and explored their proportions and coverage within existing nature reserves. The results revealed that the existing nature reserves encompass 6.38% of the total study area, 34.42% of the double-target overlapping areas, 24.59% of suitable habitats for Asian elephants, and 9.95% of ES hotspots. Consequently, there were extensive ES hotspots and suitable habitats located outside the boundaries of the existing reserves. Although these reserves reflect ES and Asian elephant habitats, ES will probably be overlooked as a conservation target. The scope of protecting the Asian Elephant National Park needs expansion based on existing nature reserves and consider dual conservation objectives to improve conservation efficiency and narrow the conservation gap. This study provides a scientific basis for developing conservation policies for the Asian Elephant National Park and offers insights into the improvement of conservation efficiency in other regions by incorporating both biodiversity and ES.
Human-wildlife conflict (HWC) threatens both human communities and many wildlife populations. We investigated the sociodemographic and spatial factors shaping tolerance towards elephants in rural Sri Lanka, where human-elephant conflict is prevalent. We surveyed residents near three protected areas (PAs: Minneriya National Park, Kaudulla National Park, Hurulu EcoPark) frequently encountering elephants. We examined how perceived risks, social norms, and individual agency interact with sociodemographic variables to shape tolerance. We tested whether the tolerance-related construct structure published in a previous study from another region of Sri Lanka replicated in our data, using confirmatory factor analysis on the same survey instrument. Three of the five tolerance-related constructs replicated with acceptable reliability (community shooting norms, utilitarian wildlife value orientations, perceived agency) while two did not, reflecting culturally specific differences in how sacredness of wild elephants is interpreted and near-universal disagreement that elephants should be near homes or croplands. Tolerance-related responses varied significantly despite the respondents' ethnoreligious homogeneity. Gender effects appeared in two distinct constructs but with different magnitudes: men reported somewhat less permissive community-shooting norms but substantially lower perceived agency in their elephant interactions. Recent change in elephant-encounter frequency emerged as the most pervasive predictor, with increasing encounters associated with weaker emotional bonds, weaker coexistence belief, and more utilitarian wildlife value orientations. Distance to the nearest PA boundary was associated with weaker coexistence belief-the first explicit individual-level link between spatial setting and a tolerance-related response in this dataset. Analyses revealed a coherent gradient in affective and behavioral responses across PAs (Kaudulla = high-tolerance pole; Minneriya = opposite pole; Hurulu intermediate), while abstract value orientations and perceived agency were spatially uniform. These findings highlight the complex interplay of sociodemographic, experiential, and spatial factors in shaping tolerance-related responses and demonstrate that what varies across the landscape is how people feel about and act toward elephants, not how they fundamentally value wildlife. The integration of theory-anchored measurement with spatial analysis provides a more nuanced understanding of tolerance and can inform targeted interventions to mitigate HWC and promote coexistence.
The global debate over the ethics and purpose of elephants in zoos has resulted in proposed legislation to cease keeping them, unless zoos can demonstrate the species' needs are met. Outdated analyses that fail to provide a current and robust appraisal of elephant survival in zoos fuels the debate. We analysed changes in life expectancy and lifespan equality in zoo elephants between 1960 and 2024, and compared these to wild or semi-wild populations. We found an increase of up to 21% in female zoo elephant life expectancy over time, and up to 44% for males. Lifespan equality increased by up to 14% in both sexes. Improvements in care have resulted in comparable or higher survival measures of zoo elephants compared to evaluated wild populations. Our findings provide information to guide zoos to ensure elephants live long meaningful lives that are, at a minimum, comparable to wild counterparts.
Rapid land-use change is compressing the space between people and wildlife at an unprecedented pace, elevating concerns of conflict between people and keystone megafauna such as the African savanna elephant (Loxodonta africana). However, the underlying drivers of human-elephant conflict (HEC) are often inferred but not causally identified, and forecasting under future scenarios is limited, restricting our ability to anticipate where and why conflict will intensify. Using a dataset on conflict events from 2004 to 2020 across a transboundary landscape in Southern Africa, we integrate causal inference (panel data regressions) and machine learning (point process models) to link mechanisms with spatial forecasts. We find that human population growth, cropland expansion, and climate-driven aridity in core elephant-protected areas drive conflict risk. Furthermore, we show that landscape features such as wildlife fences and roads constrain elephant movement in ways that drive HEC. Applying these models to projected land use, population, and climate under future coupled climate-development scenarios, we find that the area at high risk of HEC increases by 33 to 100% by 2085 with corresponding rises in event frequency. Aggressive human land-use expansion leads to the most dramatic increases in conflict, with climate impacts playing a significant but smaller role. These results identify emerging conflict hotspots decades in advance, offering actionable foresight for land-use planning and mitigation in a region critical to elephant conservation.
Hyperkeratotic psoriasis is a rare variant that includes forms such as elephantiasis, considered the rarest. It is characterized by thick, persistent plaques, resembling elephant skin, located mainly on the extremities and buttocks. Early detection and appropriate treatment, including systemic therapies, are essential for its management. A 58-year-old male patient presented in 2018 with dermatosis on his forehead, right elbow, and the backs of both hands. He was initially diagnosed with seborrheic dermatitis and chronic lichen simplex and received multiple topical therapies without improvement. In 2024, he developed new, disseminated lesions on his elbows, hands, and both legs, characterized by hyperkeratotic plaques and excoriations. A biopsy confirmed the diagnosis of elephantiasis variant hyperkeratotic psoriasis. Treatment with ustekinumab was initiated, resulting in significant improvement of the lesions. Elephantine psoriasis is a rare and difficult-to-treat variant, with few reported cases, which hinders the standardization of its management. Biologic therapies represent an effective alternative for improving prognosis, reducing complications, and preventing progression to other associated pathologies. Disseminating these cases is essential to expanding knowledge of this variant and optimizing available therapeutic options, for the benefit of patients. la psoriasis hiperqueratósica es una variante poco frecuente que incluye formas como la elefantina, considerada la más rara. Se caracteriza por placas gruesas y persistentes, con aspecto similar a la piel de un elefante, localizadas principalmente en extremidades y glúteos. La detección temprana y el tratamiento adecuado, incluyendo terapias sistémicas, son fundamentales para su manejo. paciente hombre de 58 años que inició en 2018 con dermatosis en frente, codo derecho y dorso de ambas manos, con diagnóstico inicial de dermatitis seborreica y liquen simple crónico, recibiendo múltiples terapias tópicas sin mejoría. En 2024 presentó nuevas lesiones diseminadas en codos, manos y ambas piernas, caracterizadas por placas hiperqueratósicas y excoriaciones. La biopsia confirmó el diagnóstico de psoriasis hiperqueratósica variante elefantina. Se inició tratamiento con ustekinumab, observándose mejoría significativa de las lesiones. la psoriasis elefantina es una variante rara y de difícil tratamiento, con escasos casos reportados, lo que dificulta la estandarización de su manejo. Las terapias biológicas representan una alternativa efectiva para mejorar el pronóstico, disminuir complicaciones y prevenir la progresión hacia otras patologías asociadas. La difusión de estos casos es fundamental para ampliar el conocimiento de esta variante y optimizar las opciones terapéuticas disponibles, en beneficio de los pacientes.
Southern elephant seals are highly mobile marine predators that can reflect environmental exposure to chemical elements through their diet and foraging ecology. However, information on elemental concentrations in elephant seal feces remains scarce, particularly outside Antarctic regions. In this study, the concentrations of several metals and metalloids, including rarely studied technology-critical elements, were determined in fecal samples from a juvenile male southern elephant seal (Mirounga leonina) from along the southwestern Atlantic coast of Brazil. Elemental analyses revealed the predominance of biologically essential elements such as Ca and Fe, whereas toxic elements generally occurred at lower concentrations. Rare earth elements, as well as Li, Rb, and Ti were also detected, consistent with recent dietary exposure. Comparisons with previous Antarctic studies indicated overall similar or lower concentrations for most elements, although higher concentrations of As, Be, Cs, Cu, Rb, and U were observed herein. These differences may be associated with regional environmental conditions as well as ontogenetic variations in diet between juvenile and adult individuals. This study provides the first baseline data on elemental concentrations in southern elephant seal feces from the southwestern Atlantic and highlights the usefulness of feces as a non-invasive matrix for monitoring recent environmental exposure in marine ecosystems.
Biodiversity loss in the present era requires new tools for studying nonmodel organisms. Elephants are both an endangered species and excellent models for studying complex phenotypes including size, social behavior and longevity. Here we report the first derivation of elephant (Elephas maximus) induced pluripotent stem (emiPS) cells. We achieved emiPS cells using two approaches: (1) a two-step process of chemical media induction and colony selection followed by over-expression of elephant transcription factors; and (2) a one-step process with transcription factors and HRAS mutant, HRASG12V. For both protocols, we inhibited TP53 retrogenes, which are hypothesized to confer unique cancer resistance in elephants. To confirm their reprogrammed state, we generated a functional omics catalog of emiPS cells. While these emiPS cells remain transgene-dependent, we inactivated the transgenes and differentiated emiPS cells into all three germ layers via tri-lineage differentiation, embryoid body generation and direct differentiation into putative cell types from all three layers. These methods will open new frontiers for cellular models of nonmodel organisms, including for genetic rescue and conservation.
This report describes a case of uterine leiomyoma and cystic endometrial hyperplasia in an Asian elephant (Elephas maximus). A 74-year-old female elephant in captivity was necropsied. At necropsy, the uterus was markedly enlarged, and a firm, white nodule measuring 10 × 10 × 8 cm protruded from the uterine wall into the lumen of the right uterine segment. Additionally, multiple cystic dilations (0.5-4 cm in diameter) were observed throughout the uterine segment. The mucosa was diffusely red with a moderate amount of crumbly clots in the lumen. Histologically, a benign mesenchymal neoplastic proliferation composed of multidirectional bundles of muscle tissue expanded the uterine muscular layer. The mucosa exhibited cystic dilations lined by simple squamous epithelium. In Masson's trichrome staining, the neoplastic cells showed intense red staining, consistent with muscle tissue, whereas blue staining was restricted to the supporting fibrous connective tissue. Immunohistochemistry revealed mild cytoplasmic vimentin staining, moderate desmin immunoreactivity, and strong smooth muscle actin expression in neoplastic cells. Based on the anatomopathological, histochemical, and immunohistochemical findings, uterine leiomyoma and cystic endometrial hyperplasia were diagnosed. This case highlights the importance of diagnosing neoplasms and other conditions in captive elephants to better understand the diseases affecting these animals.
Fasting is an integral component of the life-history of many species. Following abrupt weaning, northern elephant seal pups (Mirounga angustirostris) undergo an extended post-weaning fast of approximately 60 days. During this period, enteric bacterial diversity increases, suggesting that host immune regulation may facilitate the establishment of microbial communities. However, the molecular processes occurring within the intestinal mucosa during this transition remain poorly understood. To investigate these mechanisms, we characterized transcriptional changes in the enteric mucosa of male and female northern elephant seal pups sampled at weaning and after one month of fasting. Total RNA isolated from rectal swabs was sequenced and aligned to the Mirounga angustirostris reference genome. Differential gene expression and gene set enrichment analyses were used to identify genes and pathways associated with fasting and sex-specific responses. Fasting was accompanied primarily by transcriptional downregulation, including genes involved in antimicrobial defense, inflammation, protein turnover, and epithelial remodeling. In contrast, several genes associated with B-cell activity and immune recognition were upregulated. Gene Set Enrichment Analysis revealed coordinated activation of immune-regulatory pathways indicating dynamic modulation of intestinal immunity rather than generalized immune suppression. Pronounced sex-specific differences were also observed. Male pups exhibited transcriptional patterns consistent with enhanced immune tolerance, whereas females showed broader immune-pathway activation, including enrichment of pro-inflammatory and stress-response pathways. Several non-coding RNAs also displayed sex-specific changes in expression. Together, these findings suggest that fasting induces transcriptional remodeling of the gut and may contribute to immune regulation during a critical period of microbiome establishment in northern elephant seal pups.
Musth is a normal behavioral phenomenon characterized by postpubertal, periodic elevations in circulating testosterone, resulting in behavioral and physical changes in sexually mature, healthy Asian (Elephas maximus) and African (Loxodonta africana) elephant bulls. To date, the understanding of the role that musth plays on blood analytes is limited. The objective of this study was to assess serial blood analyte data (hematology, serum biochemistry, acute phase proteins, cortisol, and testosterone) relative to periods of behavioral musth vs nonmusth in two Asian elephant bulls housed at a single institution over three years. Linear and generalized linear models were used to test for differences between musth and nonmusth periods, as well as for associations of each biomarker with testosterone. In both bulls, platelet count (PLT), alkaline phosphatase (ALP), cortisol, serum amyloid A (SAA), and testosterone were statistically significantly higher during musth compared with nonmusth periods. Both bulls also displayed positive covariations of testosterone with PLT and mature heterophils. Blood urea nitrogen had a significant inverse association with testosterone in both bulls. These changes may reflect physiologic stress, systemic inflammation, and decreased urea synthesis during musth. There were otherwise limited consistencies in blood analytes between bulls, possibly due to sample size, sampling period, or individual variations. For instance, ALP, c-glutamyl transferase, SAA, and testosterone were statistically significantly higher and considered clinically relevant during musth periods in bull 1; however, similar observations for clinical relevance were absent in bull 2. Though results should be interpreted with due consideration of biological variation and other factors in individual bulls, these data provide novel information for interpretation of routine blood analytes of Asian elephant bulls, for informing clinical decision-making, and for contributing to the understanding of physiologic changes during musth periods.
In this study, we provide a comprehensive genomic analysis of population structure, genetic diversity and load across the four Asian elephant (Elephas maximus) subspecies using whole-genome sequencing data of 81 wild-born individuals, with most of them currently living under human care. Our results reveal striking contrast in inbreeding: the Bornean subspecies (E.m. borneensis) exhibits the highest level of inbreeding, with ∼ 65% of its genome in runs of homozygosity (ROH), and the lowest genome-wide heterozygosity (∼46 heterozygous sites per 100 kb). The Sumatran subspecies (E.m. sumatranus) shows intermediate levels of inbreeding (35% ROH) and heterozygosity (∼101 sites per 100 kb), while the mainland and Sri Lankan subspecies (E.m indicus and E.m. maximus) display similarly low inbreeding (∼10-11% ROH) and high heterozygosity (∼130-134 sites per 100 kb). Notably, when correcting for ROH coverage, heterozygosity levels are comparable across all four subspecies (∼136-155 sites per 100 kb), indicating that differences in genetic diversity are primarily driven by loss of heterozygosity within ROHs due to inbreeding. Genetic load remains relatively low in all subspecies, especially in highly conserved genomic regions. The high genetic diversity observed in the island-dwelling E.m. maximus subspecies likely reflects historical gene flow linked to intensive human-mediated elephant trade, raising questions about its taxonomic status. Given its high inbreeding, E.m. borneensis represents the highest conservation priority, with genetic rescue as a potential management strategy. This study highlights the urgent need for focused conservation efforts and further genomic research to safeguard the unique genetic diversity and long-term viability of Asian elephants.
The gut health of captive Asian elephants (Elephas maximus) is strongly influenced by human management. However, studies simultaneously examining the effects of both geographical location and season on the gut microbiome of these elephants remain limited. In this study, we focused on two geographically distant and ecologically distinct provinces in Thailand, which differ markedly in management practices, climate, vegetation, and landscape. Fecal samples from 20 to 10 captive Asian elephants in Lampang and Kanchanaburi, respectively, were collected during the wet and dry seasons. The gut microbiome was dominated by the phyla Firmicutes and Bacteroidota across all seasons and locations. Alpha diversity indices indicated that samples from the Lampang-wet group presented the highest diversity, whereas those from the Kanchanaburi-dry group showed the lowest. Beta-diversity analysis revealed significant differences in microbial community structure among the four groups. Functional prediction analysis indicated that microbial metabolic pathways varied between seasons, with carbohydrate metabolism pathways being more enriched in the wet season. Differences in microbiome composition and specific bacterial taxa were observed between samples from Lampang and Kanchanaburi, reflecting the unique management and environmental conditions of each region. Overall, microbial diversity was generally higher during the wet season compared to the dry season.
Chemical immobilization is essential for ensuring the safety and welfare of wildlife and researchers during animal handling. We analyzed observation data from 1,464 immobilization procedures on 625 northern elephant seals (Mirounga angustirostris) conducted between 2004 and 2025 to describe our practices and insights. Inductions used tiletamine-zolazepam (Telazol®), with supplemental doses of ketamine, diazepam, and/or Telazol for augmentation (required to achieve satisfactory induction) and maintenance (required to maintain chemical immobilization for the procedure duration). Procedures spanned a wide range of body masses (57-668 kg) across the annual cycle (i.e., seasons) and life stages, including juveniles of both sexes and adult females up to 18 years old. For adult females, 68% received Telazol induction doses within ± 0.1 mg/kg of the 1.0 mg/kg target, indicating accurate mass estimation and a broad safety margin when paired with vigilant monitoring and respiratory support as needed. Lower induction doses were associated with a higher likelihood of augmentation drug administration, whereas higher doses were more often associated with faster-than-typical inductions and the administration of a respiratory stimulant. In procedures without augmentation or respiratory stimulant administration, smaller juveniles received higher mass-specific induction doses than adults across the observed body size range, regardless of sex. These findings show that age- and season-based mass estimates can refine dosing precision within a safe range. These findings describe recorded field decisions and procedural events (e.g., timing and sequence of drug administration) rather than direct physiological measurements of anesthetic depth or safety. Our long-term dataset provides empirically derived guidance to improve immobilization efficacy, safety, and consistency for elephant seals and related species.
The simplified delivery frozen elephant trunk (SD-FET) technique enables a one-step repair of type A acute aortic dissection (AAD) with stent proximalisation and very short normothermic circulatory arrest. This study reports early and 1-year clinical outcomes together with aortic remodelling in the residual dissected aorta. Thirty consecutive patients underwent SD-FET for AAD between 2018 and 2023. Preoperative, postoperative, 1-year follow-up computed tomography scans were analyzed. True lumen (TL), false lumen (FL), and total aortic diameters were measured in four segments (proximal descending, distal descending, coeliac trunk, infra-renal) using the centerline method. Aortic remodelling was classified as positive, stable, or negative. Early and mid-term outcomes were assessed, including mortality, neurologic complications, and aortic reinterventions. Four patients (13%) died in-hospital, and four (13%) sustained postoperative stroke; no spinal cord injury occurred. During follow-up, one patient died of an aortic event and two required secondary reinterventions for downstream enlargement, yielding an overall 1-year freedom from reintervention of 92.5% [95% confidence interval (CI): 83-100%]. At the proximal descending aorta, TL increased and FL decreased significantly at 3 months and 1 year (P<0.001), with 92% of patients showing positive or stable remodelling. At the distal descending aorta and coeliac level, positive/stable remodelling was observed in 53% and 63% of cases, respectively, whereas infra-renal changes were limited. SD-FET simplifies total arch repair for AAD, reduces circulatory arrest under normothermia, and achieves acceptable early results. One-year clinical outcomes and remodelling are comparable to conventional FET, may supports its safety and efficacy, though larger cohorts and longer follow-up remain warranted.
Optimal management of the aortic arch during repair of acute type A aortic dissection remains debated. Hemiarch repair can achieve acceptable early survival, but persistent false lumen perfusion and residual distal dissection may contribute to later distal aortic enlargement or reintervention in a subset of patients. The frozen elephant trunk (FET) technique aims to improve distal aortic remodeling by covering intimal tears, expanding the true lumen, and promoting false lumen thrombosis, but it adds operative complexity because it requires more extensive arch reconstruction and supra-aortic vessel management. The Ascyrus Medical Dissection Stent (AMDS), an uncovered nitinol stent, has emerged as an adjunct to hemiarch repair. It is intended to reduce distal anastomotic new entry tears, support true lumen expansion, and facilitate distal aortic stabilization without formal total arch replacement. Contemporary evidence from the DARTS and PERSEVERE studies and observational series suggests that FET and AMDS may serve different operative goals in selected patients, although their roles are overlapping rather than mutually exclusive. FET may be more suitable when more extensive distal arch or proximal descending aortic pathology is present, whereas AMDS may be considered when a less extensive arch procedure is desired in the setting of arch instability or malperfusion. Neither approach should be viewed as universally superior. Instead, strategy should be individualized on the basis of patient age, intimal tear location, malperfusion status, operative risk, and institutional experience. AMDS may represent an additional option in selected high-risk patients.