Revisiting the Importance of Orthobunyaviruses for Animal Health: A Scoping Review of Livestock Disease, Diagnostic Tests, and Surveillance Strategies for the Simbu Serogroup.

Orthobunyaviruses (order Bunyavirales, family Peribunyaviridae) in the Simbu serogroup have been responsible for widespread epidemics of congenital disease in ruminants. Australia has a national program to monitor arboviruses of veterinary importance. While monitoring for Akabane virus, a novel orthobunyavirus was detected. To inform the priority that should be given to this detection, a scoping review was undertaken to (1) characterise the associated disease presentations and establish which of the Simbu group viruses are of veterinary importance; (2) examine the diagnostic assays that have undergone development and validation for this group of viruses; and (3) describe the methods used to monitor the distribution of these viruses. Two search strategies identified 224 peer-reviewed publications for 33 viruses in the serogroup. Viruses in this group may cause severe animal health impacts, but only those phylogenetically arranged in clade B are associated with animal disease. Six viruses (Akabane, Schmallenberg, Aino, Shuni, Peaton, and Shamonda) were associated with congenital malformations, neurological signs, and reproductive disease. Diagnostic test interpretation is complicated by cross-reactivity, the timing of foetal immunocompetence, and sample type. Serological testing in surveys remains a mainstay of the methods used to monitor the distribution of SGVs. Given significant differences in survey designs, only broad mean seroprevalence estimates could be provided. Further research is required to determine the disease risk posed by novel orthobunyaviruses and how they could challenge current diagnostic and surveillance capabilities.

Assessing risks for bovine and zoonotic tuberculosis through spatial analysis and a questionnaire survey in Fiji - A pilot study.

Mycobacterium bovis causes tuberculosis in cattle and when transmitted to humans typically causes extra-pulmonary tuberculosis (EPTB). Bovine tuberculosis (bTB) has a global distribution and is controlled in most countries to protect animal and public health. Recent studies revealed that bTB is established on dairy farms in Fiji where EPTB cases have been reported in people. The aims of this pilot investigation were to look for putative zoonotic TB (EPTB) cases in people and to evaluate practices that might contribute to the persistence and transmission of M. bovis between cattle and to humans. Existing data sets were shared between the Fiji Ministry of Agriculture and Ministry of Health and a questionnaire-based survey was implemented using One Health principles. Statistically significant co-location and close proximity of EPTB cases and bovine TB affected farms were identified. The bTB infection status of farms was significantly associated with unfenced water sources where cattle grazed. Of 247 households, 65 % shared drinking water sources with cattle and 36 % consumed raw milk without boiling, while 62 % of participants reported backyard slaughter of cattle. Several participants reported current symptoms potentially suggestive of TB (chronic cough) but the impact of smoking and history of previous TB treatment could not be evaluated. Farmers had limited understanding of the practices required to prevent bTB at farm level. Further study is recommended and should include an assessment of lifetime EPTB diagnoses, classification of farms based on more recent bTB test data and molecular typing of mycobacterial isolates from humans, cattle and the environment. A targeted awareness and education approach is required to reduce the future risk of zoonotic TB and to help ensure uptake of recommendations and practices aimed at controlling and preventing bTB.

Association between major histocompatibility complex haplotypes and susceptibility of unvaccinated and vaccinated cattle to paratuberculosis.

Bovine Johne's disease (BJD) or paratuberculosis is caused by Mycobacterium avium spp. paratuberculosis (MAP) and is a worldwide problem among domestic and wild ruminants. While vaccines are available, natural differences in background immunity between breeds within species and between individuals within herds suggest that genetic differences may be able to be exploited in marker-assisted selection as an aid to disease control. The major histocompatibility complex (MHC) is an important component in immune recognition with considerable genetic variability. In this study, associations between the MHC and resistance to BJD were explored in dairy cattle across two herds in which some of the cattle had been vaccinated with Silirum® (n = 540 cows). A BJD susceptible animal was exposed to MAP and became infected, while a resistant animal was exposed but did not become infected. There are different ways to define both exposure and infection, with different levels of stringency, therefore many classifications of the same set of animals are possible and were included in the analysis. The polymorphic regions of major histocompatibility complex class I (MHC I) and class II (MHC II) genes were amplified from the genomic DNA by PCR and sequenced, targeting exons 2 and 3 of the classical and non-classical MHC I genes and exon 2 from the DRB3, DQA1, DQA2 + 3 and DQB MHC II genes. The frequencies of MHC I and MHC II haplotypes and alleles were determined in susceptible and resistant populations. In unvaccinated animals, seven MHC I haplotypes and seven MHC II haplotypes were associated with susceptibility while two MHC I and six MHC II haplotypes were associated with resistance (P < 0.05). In vaccinated animals, two MHC I and three MHC II haplotypes were associated with susceptibility, while one MHC I and two MHC II haplotypes were associated with resistance (P < 0.05). The alleles in significant haplotypes were also identified. Case definitions with higher stringency resulted in fewer animals being included in the analyses, but the power to detect an association was not reduced and there was an increase in strength and consistency of associations. Consistent use of stringent case definitions is likely to improve agreement in future association studies.

Retrospective investigation of the 2019 African swine fever epidemic within smallholder pig farms in Oudomxay province, Lao PDR.

The 2019 African swine fever (ASF) outbreak in the Lao People's Democratic Republic (Lao PDR or Laos) represented a major epidemiologic event where a transitioning lower-middle income nation (LMIC) experienced a viral epidemic in a naïve pig population. The diversity of pig management styles creates challenges for local and regional policymakers when formulating recommendations to control an ASF outbreak. The aim of this study were to investigate the management of pigs in villages of Oudomxay province that were affected by ASF in 2019, as a case study in a smallholder pig-rasing system in northern Laos. The frequencies of well known risk factors were measured in the affected villages and the timelines and household level stock losses due to the outbreak were investigated. These findings were compared to data available from a similar outbreak in the southern province of Savannakhet. Disease control implications of these findings are discussed. Mean losses were 3.0-23.3 pigs per household, with a mean lost herd value of USD 349, 95% CI (294-415). These pig losses reflect those estimated in Savannakhet (6.7 pigs per household). However, the financial loss estimated per household was higher, USD 349 versus USD 215, possibly due to higher pig values and a higher input/output management approach in Oudomxay. The investigation revealed the presence of numerous ASF risk factors, such as swill-feeding and free-ranging. In addition, poor biosecurity practices - such as inappropriate garbage disposal and slaughtering - that could contaminate the environment were present. ASF cases occurred across all villages between June and December 2019, with outbreak periods ranging from 22-103 days. These values are consistent with the outbreak in Savannakhet; however, notable differences in management styles were observed. These findings demonstrate the need for more disease control resources from the village to the Governmental level. Villages need support in enacting context appropriate biosecurity measures, whilst the ongoing surveillance and investigation of ASF require investment in logistical and veterinary resources at the Governmental level.

Bovine tuberculosis control in Fiji: Retrospective study findings for 2015 to 2020.

Control of bovine tuberculosis (bTB) is a priority for animal health, biosecurity, and human health authorities in Fiji as evident from the long-term funding of the Bovine Brucellosis and Tuberculosis Eradication and Control program (BTEC) and notable improvements to the program described in this paper. To evaluate the performance of the Fiji BTEC program from 2015 to 2020, all available bTB data for cattle were analyzed. Data sources included BTEC bTB testing records, abattoir records and laboratory records. We integrated all information to quantify the bTB tests applied, bTB positive farms and animals, meat inspection and laboratory findings. Test coverage was highest among dairy cattle in Central Division (~73%), where bTB was highly prevalent with 7.8% of dairy cattle and 61.7% of dairy farms found to be positive between 2015 and 2020. There was no visible downward trend in the apparent prevalence of bTB over the 6-year period. During 2019 and 2020, only 21.3% (51/239) of the tested dairy farms maintained their clear status, another 8.4% (20/239) reverted to infected status after 1 year or more of being bTB clear, and most farms remained infected during these 2 years. Factors observed to be contributing to this situation were persistent infections, related in part to the significant number of untested animals, uncontrolled animal movements, and larger farm size. Similar to other developing countries, bTB remains a serious concern and further strengthening of the program targeting the main contributors to bTB persistence, along with maintenance of a comprehensive reporting and traceability system, industry awareness and government support are needed. Control of bTB in Fiji is a long-term objective that must have multiple stakeholder engagement and regular review to measure success.

Community engagement strengthens pig disease knowledge and passive surveillance in Timor-Leste.

Smallholder pig production in Timor-Leste is culturally and economically important for most households. However, regular and ongoing disease surveillance and pig husbandry training for farmers are limited. This article describes collaborative social and diagnostic research followed by a pilot community engagement program to improve farmer and technician knowledge, skills, and working relationships. There were three phases: (1) A qualitative study in 2020 to explore the experiences and knowledge of 133 pig farmers, 6 village leaders, and 16 district veterinary technicians on pig diseases and reporting, treatment methods, and access to information or assistance. (2) A pilot community engagement program in 3 villages in 2021 with the diagnostic investigation with samples analyzed from 27 dead pigs, and (3) Evaluation of community engagement and training outcomes. Results of the qualitative study revealed limited reporting of sick or dead pigs by farmers to veterinary technicians due to a lack of trust in the veterinary diagnostic system. Most technicians lacked experience with sampling or post-mortems so diagnostic training was undertaken for the pilot disease investigation. Evaluation results showed improved knowledge, motivation, and confidence of government staff and farmers. The credibility of veterinary technicians improved and gave them more confidence to work with communities. Farmers felt supported because all aspects of pig husbandry were addressed, and they were more willing to report dead or sick pigs. The project indicates that improved passive disease surveillance can be achieved by engaging communities in smallholder pig farming in Timor-Leste. Further research and testing of the approach in other districts and countries is recommended.

Investigation of animal health and husbandry practices in smallholder pig production systems in Timor-Leste.

Enhanced pig productivity on smallholder farms is recognised as a necessary strategy to enhance financial and food security in Timor-Leste where poverty and malnutrition are abundant. While poor pig health is recognised as a main constraint, information on pig herd health and management have not been thoroughly quantified. This study surveyed 120 pig owners (63 were female) and 352 of their pigs in Bacau and Bobonaro municipalities in 2018 to develop baseline information. Our analysis investigated three management systems among surveyed pig owners: confined management, characterised by permanent penning and/or tethering pigs (33.6%), semi-confined management (39.7%) and free-roaming management (27.7%). Free-roaming management was only observed in non-urban villages. Most inputs were limited across all management types with heavy reliance on cooked household scraps to feed pigs (84.7%), limited use of commercial feeds (5.1%), a lack of routine pen cleaning (73.8%), a lack of vaccination against classical swine fever (72.9%), limited use of para-veterinary services when pigs were sick (71.7%), and low treatment rates for pig skin diseases (10.3%) and intestinal parasites (8.7%). A high use of uncontrolled breeding (79.1%) was identified, accompanied by a limited knowledge of oestrus (20.7%) and gestation length (24.1%). Low output was observed with animals mainly sold when money is needed or when they were old. There was poor health with high piglet mortality rate (22.4-24.4%), moderate rates of current illness (22.4%), common occurrence of mites (12.2%), and high faecal presence of A. suum (29.0%), T. suis (10.2%), and S. ransomi (22.7%). To overcome the widespread constraints to productivity affecting all management systems, and to limit the impacts of highly infectious and often fatal African swine fever which was first reported in Timor-Leste pigs in September 2019, improved animal health and veterinary support, and education on pig management and suitable available nutrition sources are needed.

Global health security must embrace a One Health approach: Contributions and experiences of veterinarians during the COVID-19 response in Australia.

SARS-CoV-2, a betacoronavirus of likely zoonotic origin, was first reported in December 2019. Its rapid worldwide spread precipitated a range of interventions, including by veterinarians, due to impacts on human health and well-being as well as animal health and welfare. We conducted 36 key informant interviews to explore the responses of Australian veterinarians, their engagement in One Health collaboration and cooperation, and their existing and developed insights to the COVID-19 pandemic. Responses were analysed using thematic analysis. Australian veterinarians provided valuable contributions to the national COVID-19 response by protecting animal welfare, maintaining local food security, providing essential veterinary services while mitigating human health risks in clinical settings and providing both key skills and surge capacity to the human health response. This was all guided by skills in scientific literacy and evidence-based communication. Informants identified a clear and urgent need for greater One Health coordination during pandemic prevention, preparedness, and response, even in the case of a disease which largely only affects humans.

The impact of African swine fever virus on smallholder village pig production: An outbreak investigation in Lao PDR.

African swine fever virus (ASFV) causes a deadly disease of pigs which spread through southeast Asia in 2019. We investigated one of the first outbreaks of ASFV in Lao People's Democratic Republic amongst smallholder villages of Thapangtong District, Savannakhet Province. In this study, two ASFV affected villages were compared to two unaffected villages. Evidence of ASFV-like clinical signs appeared in pig herds as early as May 2019, with median epidemic days on 1 and 18 June in the two villages, respectively. Using participatory epidemiology mapping techniques, we found statistically significant spatial clustering in both outbreaks (p < 0.001). Villagers reported known risk factors for ASFV transmission - such as free-ranging management systems and wild boar access - in all four villages. The villagers reported increased pig trader activity from Vietnam before the outbreaks; however, the survey did not determine a single outbreak source. The outbreak caused substantial household financial losses with an average of nine pigs lost to the disease, and Monte Carlo analysis estimated this to be USD 215 per household. ASFV poses a significant threat to food and financial security in smallholder communities such as Thapangtong, where 40.6% of the district's population are affected by poverty. This study shows ASFV management in the region will require increased local government resources, knowledge of informal trader activity and wild boar monitoring alongside education and support to address intra-village risk factors such as free-ranging, incorrect waste disposal and swill feeding.

'It's our job': Constraints to investigation of atypical disease events-Opinions of Australian veterinarians.

Frontline health practitioners need to be adequately prepared to recognize and respond to atypical disease presentations, some of which may have zoonotic potential. Data from previous research have suggested that veterinarians may face challenges in investigation of disease events due to time and money constraints. As part of an Australia-wide survey project, veterinarians were asked to answer an open-ended question regarding potential constraints in investigation of atypical disease events where there may be concern about a zoonosis or emerging infectious disease. Qualitative data were analysed using thematic content analysis with the consideration of the respondent's area of practice and level of experience. Five main themes were identified which encapsulated constraints to disease investigation described by participants, namely: (a) financing of disease investigations, including client willingness/ability to pay in absence of alternative government schemes; (b) client-related factors, including willingness to consent to investigation and comply with instructions; (c) professional preparedness to act, related to practitioner knowledge and technical competency; (d) workplace environment, impacted by physical, logistical and managerial aspects of workplaces; and (e) access to external technical support, primarily from government veterinary services. Successful investigation and management of atypical diseases, including potential zoonoses, requires preparedness of all veterinarians. Continuing professional education for veterinarians in infection prevention and control and biosecurity, alongside adequate government funding and support will help facilitate optimal health and biosecurity outcomes. Both state and federal governments need to review existing animal health structures to ensure cohesive responses for future disease events.

Knowledge and Practices on Antibiotic Use and Antibiotic Resistance Among Smallholder Pig Farmers in Timor-Leste.

Antibiotic resistance is an emerging global health threat which is linked to the overuse and misuse of antibiotics. This study was conducted to understand the knowledge and practices of smallholder pig farmers on antibiotic use and resistance in Timor-Leste. A cross-sectional study using a structured face-to-face interview was conducted in three municipalities. The interview was piloted and implemented in the local Tetun language. This study found that knowledge of antibiotics was very poor as only 12.7% (95% CI: 6.3-23.9) of farmers reported knowing what antibiotics were, and of these only one was able to correctly explain how an antibiotic worked. None of the farmers knew about antibiotic resistance and were able to explain the concept correctly. After the definition of antibiotic was explained to the farmer, only 3.6% (95% CI: 0.8-14.9) reported that their pigs had ever received antibiotics, and the majority of farmers whose pigs had not received antibiotics reported the lack of access to veterinary services. When used, antibiotics were only used for treatment with no reported use for disease prevention or growth promotion. None of the commonly used antibiotics were critically important antimicrobials. Compliance with withdrawal periods was not routinely followed. There is a need to improve access to government veterinary services for farmers in Timor-Leste, while addressing identified knowledge gaps on antibiotics and promoting prudent use practices. The findings from this study serve as baseline information to inform future interventions.

Towards One Health clinical management of zoonoses: A parallel survey of Australian general medical practitioners and veterinarians.

General medical practitioners (GPs) and veterinarians have different but complementary knowledge and skills, with potential to enhance clinical management of zoonoses in human and animal patients through taking a One Health approach that promotes cross-professional collaboration. Ability and willingness to engage within this framework is contingent on knowledge of endemic zoonoses and an understanding of the diversity of professional roles; however, previous research suggests that this is lacking. A unique parallel survey of Australian GPs and veterinarians was implemented to ascertain clinician experience, concern, confidence and current practices regarding zoonoses management as well as willingness to engage in cross-professional collaboration where it is beneficial to overall health outcomes. Responses from 528 GPs and 605 veterinarians were analysed. Veterinarians in clinical practice were found to more frequently diagnose zoonoses; have greater concern about zoonoses; be more confident in diagnosing, managing and giving advice about the prevention of zoonoses; more likely to give advice about managing the risk of zoonoses; and more likely to initiate cross-professional referral compared to GPs (p < .001 in all areas, adjusted for other factors). The findings of this study indicate a need for change in both clinical and continuing professional education, especially for GPs, in order to better equip them in the area of zoonoses management. Exploration of pathways to encourage and facilitate cross-professional referral and collaboration will further improve clinical outcomes for both human and animal patients.

Positive attitudes towards feline obesity are strongly associated with ownership of obese cats.

Overweight and obesity (O&O) is a risk factor for several health conditions and can result in a shorter lifespan for cats. The objectives of this study were to investigate (a) cat owners' attitudes towards feline O&O and their associations with O&O in their cats; and (b) the risk factors for feline O&O and underweight, particularly those involving owner practice. An online survey comprising questions related to cat owners' attitudes towards feline O&O, owner-reported body weight and body condition of their cat, and potential risk factors for feline O&O was conducted. Primarily targeting the Australian population, the survey attracted 1,390 valid responses. In response to ten attitude-related questions, more participants (percentage range among the ten questions: 39.1-76.6%) held a disapproving attitude towards feline O&O than a neutral (17.1-31.9%) or approving attitude (3.9-27.7%). A greater proportion of participants had a more disapproving attitude towards obesity than towards overweight. Cats belonging to owners with an approving attitude towards O&O were more likely to be overweight or obese than cats belonging to owners with a disapproving attitude towards O&O. The cats had particularly high odds of overweight or obesity if their owner agreed that 'being chubby says that the cat has a quality life' (OR: 3.75, 95% CI: 2.41-5.82) and 'being fat says that the cat has a quality life' (OR: 4.98, 95%CI: 2.79-8.91). This study revealed, for the first time, that begging for food was a risk factor for O&O in cats. Other important feline risk factors for O&O identified included being middle-aged, being mixed-breed, dry food as the major diet, the amount of feed not being quantified, and frequently spending time indoors. Being over 11 years, receiving no dry food and receiving measured amounts of feed were associated with an increased odds of underweight in cats. As specific attitudes often lead to certain behaviours, reducing approving attitudes towards feline O&O may potentially reduce the frequency of O&O and the risks of O&O-related disorders in cats.

Information delivery and the veterinarian-horse owner relationship in the context of Hendra virus in Australia.

Hendra virus (HeV) is an emerging bat-borne virus endemic in Australia that can be transmitted from horses to humans and has a high fatality rate for horses and people. Controversy surrounding HeV risk mitigation measures have strained the veterinarian-horse owner relationship. This study aimed to characterise the veterinarian-horse owner relationship in general and also in the context of HeV by analysing data derived from the 'Horse Owners and Hendra Virus: A Longitudinal Study to Evaluate Risk' (HHALTER) study. Australian horse owners were recruited via emails, social media and word-of-mouth for a series of five surveys that were administered online at six-monthly intervals over a two-year period to capture baseline knowledge, attitudes and practices of horse owners regarding HeV and any changes over time. In the current study, descriptive analyses of information sources were performed to understand the use of veterinarians as a HeV information source (Surveys 1 and 5; n = 1195 and n = 617). Ordinal logistic regression analyses were conducted to determine factors associated with the frequency of horse owner contact with a veterinarian (Survey 3; n = 636). This study found a relative increase over the study period in the proportion of horse owners who had used veterinarians as HeV information source in the last 12 months (from 51.9% to 88.3%). Owning more horses, being older, having a 'duty of care' for other people working with horses and deriving the main income from horse related business were factors associated with more frequent veterinary contact. Results suggest that traditional information sources such as workshops, information packs and risk training are likely to be used by horse owners. Smart phone applications should be considered for use in the future and require further investigation for horse health communication. The findings of this study may be helpful in optimising strategies for horse health information delivery.

Animal Health Management Practices Among Smallholder Livestock Producers in Australia and Their Contribution to the Surveillance System.

The risks posed for disease introduction and spread are believed to be higher for smallholder livestock producers than commercial producers. Possible reasons for this is the notion that smallholders do not implement appropriate animal health management practices and are not part of traditional livestock communication networks. These factors contribute to the effectiveness of passive disease surveillance systems. A cross-sectional study, using a postal survey (n = 1,140) and group interviews (28 participants in three groups), was conducted to understand the animal health management and communication practices of smallholders keeping sheep, cattle, pigs, dairy goats and alpacas in Australia. These practices are crucial for an effective passive surveillance system. Findings indicate that there is a need for improvement in animal health management practices, such as contact with veterinarians and attitudes toward reporting. Results also indicate that these practices differ depending on the livestock species kept, with sheep ownership being associated with lower engagement with surveillance activities and smallholders keeping dairy goats and alpacas having in general better practices. Other factors associated with surveillance practices among participant smallholders are gender and years of experience raising livestock. Despite the differences observed, over 80% of all smallholders actively seek information on the health of their livestock, with private veterinarians considered to be a trusted source. Emergency animal diseases are not a priority among smallholders, however they are concerned about the health of their animals. The finding that veterinarians were identified by producers to be the first point of contact in the event of unusual signs of disease, strengthens the argument that private veterinarians play a vital role in improving passive surveillance. Other producers are also a point of contact for animal health advice, with government agencies less likely to be contacted. The effectiveness of on-farm passive surveillance could be enhanced by developing strategies involving both private veterinarians and producers as key stakeholders, which aim to improve awareness of disease and disease reporting responsibilities.

A Retrospective Study on Bovine Tuberculosis in Cattle on Fiji: Study Findings and Stakeholder Responses.

Bovine tuberculosis (bTB) is globally significant due to its impacts on cattle production. A Brucellosis and Tuberculosis Eradication and Control (BTEC) program commenced in Fiji during the 1980's and has since been sustained by government funding and industry cooperation. A retrospective study of bTB data obtained during the Fiji BTEC program from 1999 to 2014 was undertaken at the University of Sydney with support from the Government of Fiji. It confirmed that bTB is well-established in dairy cattle farms in Naitasiri and Tailevu provinces of Central Division on the main island of Viti Levu, and suggested that the disease is present among cattle on farms in all or most provinces across three (Central, Northern, Western) of the four divisions in the country. It was evident that despite sustained efforts, disease reduction and containment was not being achieved. Reasons contributing to this situation included the appropriateness of the protocol for conduct of the single intradermal test (SID) in cattle, absence of regular quality assurance training of BTEC field staff, lack of standard procedures for bTB data collation and evaluation, unregulated cattle movements and the presence of stray cattle. The Fiji Ministry of Agriculture responded proactively to these findings by implementing revision to the use of the SID in cattle and refresher training for staff along with the Biosecurity Authority of Fiji who implemented cattle movement restriction. A subsequent apparent outbreak of bTB in some farms due to increased detection by the new test protocol raised concerns for the local dairy industry. To clarify the status and extent of bTB infection and the challenges faced by the industry, a stakeholder forum was held in May 2017, and a new BTEC strategy was formulated and endorsed by stakeholders. bTB remains a focus for cattle disease control by the government of Fiji. This case study highlights the challenges for bTB control in Fiji and underlines the importance of technical and social considerations to achieve success in disease control.

Welfare-Adjusted Life Years (WALY): A novel metric of animal welfare that combines the impacts of impaired welfare and abbreviated lifespan.

Currently, separate measures are used to estimate the impact of animal diseases on mortality and animal welfare. This article introduces a novel metric, the Welfare-Adjusted Life Year (WALY), to estimate disease impact by combining welfare compromise and premature death components. Adapting the Disability-Adjusted Life Year approach used in human health audits, we propose WALY as the sum of a) the years lived with impaired welfare due to a particular cause and b) the years of life lost due to the premature death from the same cause. The years lived with impaired welfare are the product of the average duration of each welfare impediment, reflecting the actual condition that compromises animal welfare, the probability of an incident case developing and impaired welfare weights, representing the degree of impaired welfare. The years of life lost are calculated using the standard expected lifespan at the time of premature death. To demonstrate the concept, we estimated WALYs for 10 common canine diseases, namely mitral valve disease, dilated cardiomyopathy, chronic kidney disease, diabetes mellitus, atopic dermatitis, splenic haemangiosarcoma, appendicular osteosarcoma, cranial cruciate ligament disease, thoracolumbar intervertebral disc disease and cervical spondylomyelopathy. A survey of veterinarians (n = 61) was conducted to elicit impaired welfare weights for 35 welfare impediments. Paired comparison was the primary method to elicit weights, whereas visual analogue scale and time trade-off approaches rescaled these weights onto the desired scale, from 0 (the optimal welfare imaginable) to 1 (the worst welfare imaginable). WALYs for the 10 diseases were then estimated using the impaired welfare weights and published epidemiological data on disease impacts. Welfare impediment "amputation: one limb" and "respiratory distress" had the lowest and highest impaired welfare weights at 0.134 and 0.796, rescaled with a visual analogue scale, and 0.117 and 0.857, rescaled with time trade-off. Among the 10 diseases, thoracolumbar intervertebral disc disease and atopic dermatitis had the smallest and greatest adverse impact on dogs with WALYs at 2.83 (95% UI: 1.54-3.94) and 9.73 (95% uncertainty interval [UI]: 7.17-11.8), respectively. This study developed the WALY metric and demonstrated that it summarises welfare compromise as perceived by humans and total impact of diseases in individual animals. The WALY can potentially be used for prioritisation of disease eradication and control programs, quantification of population welfare and longitudinal surveillance of animal welfare in companion animals and may possibly be extended to production animals.

One health in our backyard: Design and evaluation of an experiential learning experience for veterinary medical students.

BACKGROUND: New educational approaches are needed to improve student understanding of the wider sociological and ecological determinants of health as well as professional responsibilities in related areas. Field trips allow students to observe interaction between plant, animal and human communities, making them an ideal tool for teaching One Health concepts. METHODS: Veterinary medical students participated in a field trip to a local parklands area, frequented by humans, dogs, horses, and wildlife. Students rotated through 5 learning activities ('stations') that focused on: (1) response to exotic animal disease incursion (equine influenza); (2) impact of cultures and belief systems on professional practice; (3) management of dangerous dogs; (4) land use change, biodiversity and emerging infectious disease; and (5) management of environmentally-acquired zoonoses (botulism). Intended learning outcomes were for students to: evaluate the various roles and responsibilities of veterinarians in society; compare the benefits and risks associated with human-animal and animal-animal interactions; and evaluate the contributions made by various professionals in safeguarding the health and welfare of animals, humans and the environment. Following the field trip, students participated in a debrief exercise and completed an online survey on their experiences. RESULTS: Feedback from students collected in 2016/2017 (n = 211) was overwhelmingly positive. The learning experience at each station was rated as 4 ('Good') or 5 ('Very Good') out of 5 by 82-96% of students. Responses to closed- and open-ended questions - as well as outputs generated in the debrief session - indicated that students achieved the learning outcomes. Overall, 94% of students agreed or strongly agreed that they had a better understanding of One Health because of the field trip. CONCLUSIONS: Field trips to local parklands are effective in promoting learning about One Health and can be incorporated into the core curriculum to maximize student exposure at relatively low cost.

Low- and High-Pathogenic Avian Influenza H5 and H7 Spread Risk Assessment Within and Between Australian Commercial Chicken Farms.

This study quantified and compared the probability of avian influenza (AI) spread within and between Australian commercial chicken farms via specified spread pathways using scenario tree mathematical modeling. Input values for the models were sourced from scientific literature, expert opinion, and a farm survey conducted during 2015 and 2016 on Australian commercial chicken farms located in New South Wales (NSW) and Queensland. Outputs from the models indicate that the probability of no establishment of infection in a shed is the most likely end-point after exposure and infection of low-pathogenic avian influenza (LPAI) in one chicken for all farm types (non-free range meat chicken, free range meat chicken, cage layer, barn layer, and free range layer farms). If LPAI infection is established in a shed, LPAI is more likely to spread to other sheds and beyond the index farm due to a relatively low probability of detection and reporting during LPAI infection compared to high-pathogenic avian influenza (HPAI) infection. Among farm types, the median probability for HPAI spread between sheds and between farms is higher for layer farms (0.0019, 0.0016, and 0.0031 for cage, barn, and free range layer, respectively) than meat chicken farms (0.00025 and 0.00043 for barn and free range meat chicken, respectively) due to a higher probability of mutation in layer birds, which relates to their longer production cycle. The pathway of LPAI spread between sheds with the highest average median probability was spread via equipment (0.015; 5-95%, 0.0058-0.036) and for HPAI spread between farms, the pathway with the highest average median probability was spread via egg trays (3.70 × 10-5; 5-95%, 1.47 × 10-6-0.00034). As the spread model did not explicitly consider volume and frequency of the spread pathways, these results provide a comparison of spread probabilities per pathway. These findings highlight the importance of performing biosecurity practices to limit spread of the AI virus. The models can be updated as new information on the mechanisms of the AI virus and on the volume and frequency of movements shed-to-shed and of movements between commercial chicken farms becomes available.

Wildlife Presence and Interactions with Chickens on Australian Commercial Chicken Farms Assessed by Camera Traps.

The types of wildlife and the frequency of their visits to commercial chicken farms in Australia were assessed using infrared and motion-sensing camera traps. Cameras were set up on 14 free-range layer farms, three cage layer farms, two barn layer farms, five non-free-range meat chicken farms, and six free-range meat chicken farms in the Sydney basin region and South East Queensland. Wildlife visits were found on every farm type and were most frequent on cage layer farms (73%), followed by free-range layer farms (15%). The common mynah ( Acridotheres tristis) was the most frequent wildlife visitor in the study (23.9%), followed by corvids (22.9%) and Columbiformes (7.5%). Most wildlife visits occurred during the day from 6 am to 6 pm (85%). There were infrequent observations of direct contact between chickens and wildlife, suggesting the indirect route of pathogen transfer may be more significant. The level of biosecurity on the farm is suggested to impact the frequency of wildlife visits more so than the farm type.