Veterinary Science Collected Works - Research Publications
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ItemSpatial and temporal distribution of foot and mouth disease outbreaks in Amhara region of Ethiopia in the period 1999 to 2016(BMC, 2020-06-09)BACKGROUND: Foot and mouth disease (FMD) is an economically important trans-boundary viral disease of cloven-hoofed animals. It is caused by FMD virus, which belongs to the genus Aphthovirus and family Picornaviridae. FMD is a well-established endemic disease in Ethiopia since it was first detected in 1957. This retrospective study was carried out to identify the spatial and temporal distribution of FMD outbreaks in Amhara region of Ethiopia using 18 years (January 1999-December 2016) reported outbreak data. RESULTS: A total of 636 FMD outbreaks were reported in Amhara region of Ethiopia between 1999 and 2016 with an average and median of 35 and 13 outbreaks per year respectively. In this period, FMD was reported at least once in 58.5% of the districts (n = 79) and in all administrative zones of the region (n = 10). The average district level incidence of FMD outbreaks was 4.68 per 18 years (0.26 per district year). It recurs in a district as epidemic, on average in 5.86 years period. The incidence differed between administrative zones, being the lowest in East Gojjam and highest in North Shewa. The occurrence of FMD outbreaks was found to be seasonal with peak outbreaks in March and a low in August. The long-term trend of FMD outbreaks indicates a slight, but statistically significant (p < 0.001) decrease over the study period. CONCLUSION: FMD occurred in all zones of the region and showed statistically significant decrease in the long-term trend. Numbers of outbreaks were relatively higher during dry season. The spatial and temporal distribution identified in this study should be considered in controlling the disease. As unregulated and frequent animal movements are the likely causes of high outbreak occurrence during the dry season, animal movement regulations should be considered for the long-term control of FMD.
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ItemNo Preview Available"I Had No Idea That Other People in the World Thought Differently to Me": Ethical Challenges in Small Animal Veterinary Practice and Implications for Ethics Support and Education(University of Toronto Press, 2020-12-01)Although veterinarians encounter ethical challenges in their everyday practice, few studies have examined how they make sense of and respond to them. This research used semi-structured interviews and a qualitative methodology (phenomenological and constructivist/interpretivist approaches) to explore ethical challenges experienced by seven small animal city veterinarians and their ethical decision-making strategies. Thematic analysis of the interview transcripts identified four broad ethical issues: The first concerned disagreements about the best interests of the animal; the second centered on clinical uncertainty about the most appropriate treatment for the animal; the third involved factors influencing ethical reasoning and decision making; and the fourth concerned how ethics education might prepare veterinary students for future ethical decision making. An overarching theme identified in the analysis was one of enormous personal distress. Furthermore, a sense of veterinarians being interested in how others might think and feel about ethical challenges came through in the data. The results give insight into how veterinarians experience and respond to ethical challenges. The research also provides empirical information about everyday practice to inform future education in ethics and ethical decision making for veterinary students.
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ItemExpression of HIF-1α and VEGF in feline mammary gland carcinomas: association with pathological characteristics and clinical outcomes(BMC, 2020-05-06)BACKGROUND: The microenvironment within solid malignant tumors, including feline mammary gland carcinomas (FMGCs), is commonly hypoxic, possibly due to the lack of functional blood vessels in rapidly proliferating neoplastic tissue. Malignant cells can undergo genetic and adaptive changes that prevent them from dying due to oxygen deprivation through expressions of hypoxia-inducible factor 1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF). Therefore, HIF-1α and VEGF are ideal biomarkers for cancer therapy and prognostic evaluation. The aims of this study were to evaluate the expression of HIF-1α and VEGF in feline mammary carcinomas and analyze their correlations with clinical and pathological factors, such as clinical stage, histologic grading, regional metastasis, and overall survival rate. RESULTS: Paraffin-embedded tissue samples collected from 72 cats with FMGCs were retrospectively studied. Histologic pattern and histologic grading (Elston and Ellis grading system) of these FMGCs were determined. Our data indicated that grade II tubulopapillary carcinomas (43/72, 59.7%) prevailed in this study, and most FMCGs showed apparent necrosis, squamous metaplasia, and intratumoral stromal response. According to the results of immunohistochemical (IHC) stainings performed in tissue microarrays (TMAs), HIF-1α and VEGF overexpressions were respectively noted in 69.4% (50/72) and 77.8% (56/72) of FMGC cases. Chi-square test showed no correlation of HIF-1α overexpression with clinical and pathological factors. VEGF overexpression was significantly correlated with histologic pattern (p = 0.021), stromal response (p = 0.048), squamous metaplasia (p = 0.001), and lymphovascular invasion (p = 0.007). However, neither HIF-1α nor VEGF overexpression was correlated with histologic grading and metastasis. Of 38 cats with 1-year follow-up, IHC stainings of HIF-1α and VEGF were performed on whole tissue sections. The results showed that overexpression of HIF-1α was significantly correlated with the overall survival rate (p < 0.05) (log-rank test), whereas there was no significant correlation between VEGF overexpression and overall survival rate. CONCLUSIONS: This study suggests that the overexpression of HIF-1α may indicate poor prognosis/overall survival rate in cats with FMGCs. Developing compounds that inhibit HIF-1α may be a potential approach to FMGC treatment.
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ItemNot all dogs are equal: perception of canine welfare varies with context(UNIV FEDERATION ANIMAL WELFARE, 2020-02-01)Community attitudes drive societal expectations, influencing government and industry regulations that determine standards of care for industries reliant on animals. It is important for dog industry stakeholders to understand public perceptions and attitudes, to inform management strategy priorities relating to animal welfare. This study sought to determine if the welfare status of dogs (Canis familiaris) is important to people and whether the perceived level of welfare varies with dog context (eg companion, protection, stock herding, assistance, sporting, free-roaming, wild, etc). Over 2,000 self-selected adults completed a voluntary, internet-based questionnaire. Responses were received from more than twelve countries and from a range of stakeholders with varied experiences. Perceived welfare status of dogs varied significantly across 17 dog contexts and roles, from extremely low (eg fighting dogs) to very high (eg guide dogs). Over 95% of respondents agreed that the welfare of dogs was very important to them. Demographic features of respondents did not relate to meaningful differences in reported importance of canine welfare or ratings of perceived welfare of dogs. The constructs underlying how people perceive the welfare of dogs appear complex and multi-dimensional. As public scrutiny forces reassessment of the welfare status of animals used in various contexts, proactive management of perceived welfare issues by companion and working dog industry stakeholders, including government, industry organisations, advocacy groups, and animal welfare researchers, is likely to be key to the sustainable participation of dogs in these roles.
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ItemHow management of grief associated with ending the life of an animal is taught to Australasian veterinary students(WILEY, 2020-08)OBJECTIVE: Veterinarians have an important role in supporting and understanding their clients' grief. Veterinary schools have a duty to teach students how best to manage grief - both that of the students/future veterinarians and the clients. This study explores how grief management, associated with ending the life of an animal, was taught to students in eight Australasian veterinary schools. METHODS: A questionnaire-style interview guide was used by a representative at each university to conduct structured interviews with educators in a snowball sampling approach. Educators were interviewed about the teaching of grief management for four categories of animals: livestock, equine, companion and avian/wildlife. The terms used by participants to describe what they taught were grouped into common themes. Teaching was defined by individual participants and included structured and unstructured approaches. The stage in the degree (preclinical or clinical years) that grief management was taught in the veterinary curriculum and by whom (e.g. clinicians or psychologists) is also described. RESULTS: Grief management was taught more in preclinical than clinical years. However, due to how grief was characterised, much of this teaching was general 'nonspecific' teaching that included all categories of animals. Client grief was taught more generically, whereas, grief of veterinarians was taught using specific examples given by clinicians. CONCLUSION: A more robust end-of-life (EoL) management curriculum that includes all aspects of grief management is likely to increase job satisfaction, client happiness and professional satisfaction.
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ItemCarbon sink strength of nodules but not other organs modulates photosynthesis of faba bean (Vicia faba) grown under elevated [CO2] and different water supply(WILEY, 2020-07)Photosynthetic stimulation by elevated [CO2 ] (e[CO2 ]) may be limited by the capacity of sink organs to use photosynthates. In many legumes, N2 -fixing symbionts in root nodules provide an additional sink, so that legumes may be better able to profit from e[CO2 ]. However, drought not only constrains photosynthesis but also the size and activity of sinks, and little is known about the interaction of e[CO2 ] and drought on carbon sink strength of nodules and other organs. To compare carbon sink strength, faba bean was grown under ambient (400 ppm) or elevated (700 ppm) atmospheric [CO2 ] and subjected to well-watered or drought treatments, and then exposed to 13 C pulse-labelling using custom-built chambers to track the fate of new photosynthates. Drought decreased 13 C uptake and nodule sink strength, and this effect was even greater under e[CO2 ], and was associated with an accumulation of amino acids in nodules. This resulted in decreased N2 fixation, and increased accumulation of new photosynthates (13 C/sugars) in leaves, which in turn can feed back on photosynthesis. Our study suggests that nodule C sink activity is key to avoid sink limitation in legumes under e[CO2 ], and legumes may only be able to achieve greater C gain if nodule activity is maintained.
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ItemDietary Uptake and Depuration Kinetics of Perfluorooctane Sulfonate, Perfluorooctanoic Acid, and Hexafluoropropylene Oxide Dimer Acid (GenX) in a Benthic Fish(Wiley, 2020-03)Per‐ and poly‐fluoroalkyl substances (PFAS) are ubiquitously distributed throughout aquatic environments and can bioaccumulate in organisms. We examined dietary uptake and depuration of a mixture of 3 PFAS: perfluorooctanoic acid (PFOA; C8HF15O2), perfluorooctane sulfonate (PFOS; C8HF17SO3), and hexafluoropropylene oxide dimer acid (HPFO‐DA; C6HF11O3; trade name GenX). Benthic fish (blue spot gobies, Pseudogobius sp.) were fed contaminated food (nominal dose 500 ng g–1) daily for a 21‐d uptake period, followed by a 42‐d depuration period. The compounds PFOA, linear‐PFOS (linear PFOS), and total PFOS (sum of linear and branched PFOS) were detected in freeze‐dried fish, whereas GenX was not, indicating either a lack of uptake or rapid elimination (<24 h). Depuration rates (d–1) were 0.150 (PFOA), 0.045 (linear‐PFOS), and 0.042 (linear+branched‐PFOS) with corresponding biological half‐lives of 5.9, 15, and 16 d, respectively. The PFOS isomers were eliminated differently, resulting in enrichment of linear‐PFOS (70–90%) throughout the depuration period. The present study is the first reported study of GenX dietary bioaccumulation potential in fish, and the first dietary study to investigate uptake and depuration of multiple PFASs simultaneously, allowing us to determine that whereas PFOA and PFOS accumulated as expected, GenX, administered in the same way, did not appear to bioaccumulate.
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ItemDetection of Helminth Ova in Wastewater Using Recombinase Polymerase Amplification Coupled to Lateral Flow Strips(MDPI, 2020-03)Ascaris lumbricoides is a major soil-transmitted helminth that is highly infective to humans. The ova of A. lumbricoides are able to survive wastewater treatment, thus making it an indicator organism for effective water treatment and sanitation. Hence, Ascaris ova must be removed from wastewater matrices for the safe use of recycled water. Current microscopic techniques for identification and enumeration of Ascaris ova are laborious and cumbersome. Polymerase chain reaction (PCR)-based techniques are sensitive and specific, however, major constraints lie in having to transport samples to a centralised laboratory, the requirement for sophisticated instrumentation and skilled personnel. To address this issue, a rapid, highly specific, sensitive, and affordable method for the detection of helminth ova was developed utilising recombinase polymerase amplification (RPA) coupled with lateral flow (LF) strips. In this study, Ascaris suum ova were used to demonstrate the potential use of the RPA-LF assay. The method was faster (< 30 min) with optimal temperature at 37 °C and greater sensitivity than PCR-based approaches with detection as low as 2 femtograms of DNA. Furthermore, ova from two different helminth genera were able to be detected as a multiplex assay using a single lateral flow strip, which could significantly reduce the time and the cost of helminth identification. The RPA-LF system represents an accurate, rapid, and cost-effective technology that could replace the existing detection methods, which are technically challenged and not ideal for on-site detection in wastewater treatment plants.
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ItemFusion of Spectral and Structural Information from Aerial Images for Improved Biomass Estimation(MDPI, 2020-10)Efficient, precise and timely measurement of plant traits is important in the assessment of a breeding population. Estimating crop biomass in breeding trials using high-throughput technologies is difficult, as reproductive and senescence stages do not relate to reflectance spectra, and multiple growth stages occur concurrently in diverse genotypes. Additionally, vegetation indices (VIs) saturate at high canopy coverage, and vertical growth profiles are difficult to capture using VIs. A novel approach was implemented involving a fusion of complementary spectral and structural information, to calculate intermediate metrics such as crop height model (CHM), crop coverage (CC) and crop volume (CV), which were finally used to calculate dry (DW) and fresh (FW) weight of above-ground biomass in wheat. The intermediate metrics, CHM (R2 = 0.81, SEE = 4.19 cm) and CC (OA = 99.2%, Κ = 0.98) were found to be accurate against equivalent ground truth measurements. The metrics CV and CV×VIs were used to develop an effective and accurate linear regression model relationship with DW (R2 = 0.96 and SEE = 69.2 g/m2) and FW (R2 = 0.89 and SEE = 333.54 g/m2). The implemented approach outperformed commonly used VIs for estimation of biomass at all growth stages in wheat. The achieved results strongly support the applicability of the proposed approach for high-throughput phenotyping of germplasm in wheat and other crop species.
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ItemDistribution and conservation of known secondary metabolite biosynthesis gene clusters in the genomes of geographically diverse Microcystis aeruginosa strains(CSIRO PUBLISHING, 2020)The cyanobacterium Microcystis aeruginosa has been linked to toxic blooms worldwide. In addition to producing hepatotoxic microcystins, many strains are capable of synthesising a variety of biologically active compounds, including protease and phosphatase inhibitors, which may affect aquatic ecosystems and pose a risk to their use. This study explored the distribution, composition and conservation of known secondary metabolite (SM) biosynthesis gene clusters in the genomes of 27 M. aeruginosa strains isolated from six different Köppen–Geiger climates. Our analysis identified gene clusters with significant homology to nine SM biosynthesis gene clusters spanning four different compound classes: non-ribosomal peptides, hybrid polyketide–non-ribosomal peptides, cyanobactins and microviridins. The aeruginosin, microviridin, cyanopeptolin and microcystin biosynthesis gene clusters were the most frequently observed, but hybrid polyketide–non-ribosomal peptide biosynthesis clusters were the most common class overall. Although some biogeographic relationships were observed, taxonomic markers and geography were not reliable indicators of SM biosynthesis cluster distribution, possibly due to previous genetic deletions or horizontal gene transfer events. The only cyanotoxin biosynthesis gene cluster identified in our screening study was the microcystin synthetase (mcy) gene cluster, suggesting that the production of non-microcystin cyanotoxins by this taxon, such as anatoxin-a or paralytic shellfish poison analogues, is either absent or rare.