ORCID Profile
0000-0002-6603-2385
Current Organisation
Texas A&M University-Kingsville Caesar Kleberg Wildlife Research Institute
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Publisher: Springer Science and Business Media LLC
Date: 06-01-2021
DOI: 10.1186/S13071-020-04500-9
Abstract: Sarcoptic mange causes significant animal welfare and occasional conservation concerns for bare-nosed wombats ( Vombatus ursinus ) throughout their range. To date, in situ chemotherapeutic interventions have involved macrocytic lactones, but their short duration of action and need for frequent re-administration has limited treatment success. Fluralaner (Bravecto® MSD Animal Health), a novel isoxazoline class ectoparasiticide, has several advantageous properties that may overcome such limitations. Fluralaner was administered topically at 25 mg/kg ( n = 5) and 85 mg/kg ( n = 2) to healthy captive bare-nosed wombats. Safety was assessed over 12 weeks by clinical observation and monitoring of haematological and biochemical parameters. Fluralaner plasma pharmacokinetics were quantified using ultra-performance liquid chromatography and tandem mass spectrometry. Efficacy was evaluated through clinical assessment of response to treatment, including mange and body condition scoring, for 15 weeks after topical administration of 25 mg/kg fluralaner to sarcoptic mange-affected wild bare-nosed wombats ( n = 3). Duration of action was determined through analysis of pharmacokinetic parameters and visual inspection of study subjects for ticks during the monitoring period. Methods for diluting fluralaner to enable ‘pour-on’ application were compared, and an economic and treatment effort analysis of fluralaner relative to moxidectin was undertaken. No deleterious health impacts were detected following fluralaner administration. Fluralaner was absorbed and remained quantifiable in plasma throughout the monitoring period. For the 25 mg/kg and 85 mg/kg treatment groups, the respective means for maximum recorded plasma concentrations (C max ) were 6.2 and 16.4 ng/ml for maximum recorded times to C max , 3.0 and 37.5 days and for plasma elimination half-lives, 40.1 and 166.5 days. Clinical resolution of sarcoptic mange was observed in all study animals within 3–4 weeks of treatment, and all wombats remained tick-free for 15 weeks. A suitable product for diluting fluralaner into a ‘pour-on’ was found. Treatment costs were competitive, and predicted treatment effort was substantially lower relative to moxidectin. Fluralaner appears to be a safe and efficacious treatment for sarcoptic mange in the bare-nosed wombat, with a single dose lasting over 1–3 months. It has economic and treatment-effort-related advantages over moxidectin, the most commonly used alternative. We recommend a dose of 25 mg/kg fluralaner and, based on the conservative assumption that at least 50% of a dose makes dermal contact, Bravecto Spot-On for Large Dogs as the most appropriate formulation for adult bare-nosed wombats.
Publisher: Western North American Naturalist
Date: 08-2011
DOI: 10.3398/064.071.0210
Publisher: Springer Science and Business Media LLC
Date: 06-06-2021
Publisher: Wiley
Date: 23-08-2017
Publisher: US Geological Survey
Date: 2023
DOI: 10.3133/FS20233045
Publisher: CSIRO Publishing
Date: 2021
DOI: 10.1071/AM20004
Abstract: The northern hairy-nosed wombat (Lasiorhinus krefftii) is an iconic marsupial endemic to Australia, recognised globally for its status as the largest, herbivorous burrowing mammal. Owing to historical challenges, including anthropogenic conflict and environmental threats, the species was pushed to near extinction and was officially classified as Critically Endangered in 1996. Establishing an effective conservation plan is complicated by ongoing and novel threats as well as by aspects of the species’ ecology that remain unstudied due to its neophobic and nocturnal behaviour. To identify areas where additional research is needed, we conducted a comprehensive search of the literature published on the northern hairy-nosed wombat from 1980 to 2019 to identify where knowledge gaps exist and to suggest where future efforts may be focussed. We found that the breeding ecology, in particular, of the northern hairy-nosed wombat is largely unstudied but could be vital in conservation efforts. Further, there is a need to establish additional populations, and several threats – including disease, invasive species, and climate change – may require ongoing management action to ensure the species’ longevity.
Publisher: Wiley
Date: 23-07-2019
Abstract: Long‐term pathogen control or eradication in wildlife is rare and represents a major challenge in conservation. Control is particularly difficult for environmentally transmitted pathogens, including some of the most conservation‐critical wildlife diseases. We undertook a treatment programme aimed at population‐scale eradication of the environmentally transmitted Sarcoptes scabiei mite (causative agent of sarcoptic mange) during an epizootic in bare‐nosed wombats ( Vombatus ursinus ). Field trial results were used to parameterize a mechanistic host‐disease model that explicitly described indirect transmission, host behaviour and viable disease intervention methods. Model analysis shows that elimination of S. scabiei in the wild is most sensitive to the success of treatment delivery, and duration of the programme. In addition, we found the frequency that wombats switch burrows was an important positive driver of mite persistence. Synthesis and applications . This research emphasizes the utility of applying model‐guided management techniques in order to achieve practical solutions for controlling disease in the field. We find that control efforts of Sarcoptes scabiei are most successful when simultaneous improvements are made to the current best‐practice protocol, specifically the implementation of better treatment application methods in combination with a longer lasting treatment. These suggested management changes may also reduce the resources and field effort required to implement a successful regime. Furthermore, our approach and findings have applicability to other species affected by S. scabiei (e.g. wolves, red foxes, Spanish ibex and American black bear), as well as other conservation‐critical systems involving environmental transmission (e.g. bat white‐nose syndrome and hibian chytridiomycosis).
Publisher: Elsevier BV
Date: 09-2023
Publisher: Wiley
Date: 2022
DOI: 10.1002/JWMG.22154
Abstract: Secondary sexual traits (e.g., horns and antlers) have ecological and evolutionary importance and are of management interest for game species. Yet, how these traits respond to emerging threats like infectious disease remains underexplored. Infectious pneumonia threatens bighorn sheep ( Ovis canadensis ) populations across North America and we hypothesized it may also reduce horn growth in male sheep. We assess the effect of pneumonia on horn size in male bighorn sheep using 12 herd datasets from across the western United States that had horn growth and disease data. Disease resulted in 12–35% reduction in increment (yearly) length and 3–13% reduction in total horn length in exposed in iduals. The disease effect was prolonged when pathogens continued to circulate in sheep populations. Further, disease likely delays the age at which horns reach ¾‐curl and prevents achievement of full‐curl. This is further evidenced with 6 of the 12 herds experiencing an increase in average age at harvest following die‐off events.
Publisher: Wiley
Date: 23-05-2023
Abstract: Understanding the spatial dynamics and drivers of wildlife pathogens is constrained by s ling logistics, with implications for advancing the field of landscape epidemiology and targeted allocation of management resources. However, visually apparent wildlife diseases, when combined with remote‐surveillance and distribution modelling technologies, present an opportunity to overcome this landscape‐scale problem. Here, we investigated dynamics and drivers of landscape‐scale wildlife disease, using clinical signs of sarcoptic mange (caused by Sarcoptes scabiei ) in its bare‐nosed wombat (BNW Vombatus ursinus ) host. We used 53,089 camera‐trap observations from over 3261 locations across the 68,401 km 2 area of Tasmania, Australia, combined with landscape data and ensemble species distribution modelling (SDM). We investigated: (1) landscape variables predicted to drive habitat suitability of the host (2) host and landscape variables associated with clinical signs of disease in the host and (3) predicted locations and environmental conditions at greatest risk of disease occurrence, including some Bass Strait islands where BNW translocations are proposed. We showed that the Tasmanian landscape, and ecosystems therein, are nearly ubiquitously suited to BNWs. Only high mean annual precipitation reduced habitat suitability for the host. In contrast, clinical signs of sarcoptic mange disease in BNWs were widespread, but heterogeneously distributed across the landscape. Mange (which is environmentally transmitted in BNWs) was most likely to be observed in areas of increased host habitat suitability, lower annual precipitation, near sources of freshwater and where topographic roughness was minimal (e.g. human modified landscapes, such as farmland and intensive land‐use areas, shrub and grass lands). Thus, a confluence of host, environmental and anthropogenic variables appear to influence the risk of environmental transmission of S. scabiei . We identified that the Bass Strait Islands are highly suitable for BNWs and predicted a mix of high and low suitability for the pathogen. This study is the largest spatial assessment of sarcoptic mange in any host species, and advances understanding of the landscape epidemiology of environmentally transmitted S. scabiei . This research illustrates how host‐pathogen co‐suitability can be useful for allocating management resources in the landscape.
Publisher: Public Library of Science (PLoS)
Date: 23-03-2015
Publisher: The Royal Society
Date: 04-2018
DOI: 10.1098/RSOS.180018
Abstract: Sarcoptic mange, caused by the parasitic mite Sarcoptes scabiei , causes a substantive burden of disease to humans, domestic animals and wildlife, globally. There are many effects of S. scabiei infection, culminating in the disease which hosts suffer. However, major knowledge gaps remain on the pathogenic impacts of this infection. Here, we focus on the bare-nosed wombat host ( Vombatus ursinus ) to investigate the effects of mange on: (i) host heat loss and thermoregulation, (ii) field metabolic rates, (iii) foraging and resting behaviour across full circadian cycles, and (iv) fatty acid composition in host adipose, bone marrow, brain and muscle tissues. Our findings indicate that mange-infected V. ursinus lose more heat to the environment from alopecia-affected body regions than healthy in iduals. Additionally, mange-infected in iduals have higher metabolic rates in the wild. However, these metabolic demands are difficult to meet, because infected in iduals spend less time foraging and more time inactive relative to their healthy counterparts, despite being outside of the burrow for longer. Lastly, mange infection results in altered fatty acid composition in adipose tissue, with increased amounts of omega-6 acids, and decreased amounts of omega-3 acids, a consequence of chronic cutaneous inflammation and inhibition of anti-inflammatory responses. These findings highlight the interactions of mange-induced physiological and behavioural changes, and have implications for the treatment and rehabilitation of infected in iduals.
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/AM18013
Abstract: Environmental exposure to Sarcoptes scabiei mites in burrows is considered the dominant mechanism of sarcoptic mange transmission among wombats. We document elevated activity of bare-nosed wombats at a burrow with subterranean water access relative to burrows without this resource, suggesting that some burrows may contribute more to mange transmission than others.
Publisher: Museum and Institute of Zoology at the Polish Academy of Sciences
Date: 02-02-2023
Publisher: Wiley
Date: 21-03-2019
DOI: 10.1111/EVA.12785
Publisher: Wildlife Disease Association
Date: 2019
DOI: 10.7589/2018-04-101
Abstract: The invasive ectoparasite Sarcoptes scabiei affects the welfare and conservation of Australian marsupials. Molecular data suggest that spillover from other hosts may be responsible for the emergence of this infectious disease, but the scale of such studies is limited. We performed expanded molecular typing of the S. scabiei mitochondrial cox1 gene from 81 skin scrapings from infested wombats ( Vombatus ursinus), koalas ( Phascolarctos cinereus), red foxes ( Vulpes vulpes), and dogs ( Canis lupus familiaris) across Australia. Combined with existing S. scabiei sequences, our analysis revealed 16 haplotypes among Australian animals, sharing between 93.3% and 99.7% sequence similarity. While some sequences were unique to specific hosts or to Australia, key haplotypes could be detected across several marsupial hosts as well as to wild or domestic canids in Australia. We identified 43 cox1 haplotypes with many Australian haplotypes identical to S. scabiei mites from inside and outside Europe. We concluded that multiple introduction events were plausible explanations to the origin and emergence of this parasite into Australian marsupials and that disease spillover from canids was likely. Together, our greatly expanded S. scabiei sequence dataset provided a more nuanced picture of both spillover and sustained intraspecific transmission for this important parasite.
Publisher: Annual Reviews
Date: 22-09-2024
Publisher: Wiley
Date: 03-2021
DOI: 10.1002/ECE3.7159
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0SM01230K
Abstract: The bare-nosed wombat ( Vombatus ursinus ) is a fossorial, herbivorous, Australian marsupial, renowned for its cubic feces.
Location: United States of America
No related grants have been discovered for Alynn Martin.