Aflatoxins are secondary metabolites produced by Aspergillus spp which can lead to serious health outcomes for both people and animals if ingested via contaminated food. An outbreak of presumptive aflatoxin poisoning affected dogs in southern Malawi after consuming contaminated home-cooked maize. The dogs presented with clinical signs consistent with liver damage. Blood tests, necropsy findings and histological examination of liver tissue revealed changes consistent with hepatic damage. Tests on 16 households’ maize samples, representing some of the affected dogs' feed, identified detectable aflatoxin levels. This report demonstrates the probable effects aflatoxin can have on canine health and the potential effects to human health through consumption of unregulated maize. Veterinarians play a key role in identifying such outbreaks, not only reducing dog deaths but also acting as a crucial early warning system for potential human health risks.

Veterinarians are custodians of animal welfare, ensuring practices remain current and effective in the face of the ever-changing demands of the profession. Continuing Professional Development (CPD) is essential for protecting animal welfare, however access to quality CPD is a challenge in many countries. India has one of the fastest growing veterinary industries globally, emphasising the importance of accessible CPD opportunities that are relevant to this setting. This study used focus groups to explore how Indian veterinarians identify relevant CPD, barriers they encounter, and their experiences with CPD. We describe three themes: (1) ‘career vs calling’, where veterinarians’ extrinsic and intrinsic motivational factors were identified, such as their desire to protect animal welfare; (2) being ‘willing to learn but can’t’, with context-specific barriers, such as accessing reliable CPD information; and (3) ‘real interactions matter’, where participants described how pedagogical design influenced their choices, e.g. being able to observe animal welfare improvements through practical teaching. We have three recommendations: firstly, to improve CPD learning opportunities informed by evidence-based methods, to meet knowledge and skills gaps such as the high demand for practically focused training; secondly, the development of a unified accreditation and quality assurance framework to assess content, relevance and delivery standards of available CPD options to veterinarians; and, lastly, improved support from employers to address current barriers and facilitate attendance. These findings contribute to the current knowledge gap of factors that influence Indian veterinarians’ experiences of attaining relevant, accessible CPD and makes suggestions to improve standards of veterinary care and, ultimately, patient welfare.

Background: Old World orthohantaviruses are the aetiological agent of Haemorrhagic Fever with Renal Syndrome (HFRS) disease. Worldwide, the two most prominent pathogens of HFRS are Seoul orthohantavirus (SEOV) and Hantaan orthohantavirus (HTNV). There is currently no specific treatment nor widely licensed vaccine form hantaviruses. Methods: This study developed a virus-vectored vaccine approach using modified vaccinia Ankara (MVA) incorporating a SEOV-HTNV chimeric nucleoprotein antigen. Results: The vaccine demonstrated the induction of humoral and cellular immunity. In the absence of a disease model, a reduction in the viral load of a susceptible mouse strain with type-I interferon receptor deficiency (A129) was used to ascertain protective effects after challenge with SEOV. Results demonstrated a significant reduction in and/or clearance of viral RNA in immunised animals. Conclusions: An MVA viral vector vaccine incorporating the nucleoprotein as antigen offers a promising approach for Hantavirus vaccine development.

Catch-neuter-vaccinate-release (CNVR) programmes for free-roaming dogs (FRD) are humane and effective in controlling dog populations in developing countries. However, each component, from capture to release, can impact an individual animal’s welfare. This study aimed to develop a standardised welfare assessment scoring system for evaluating the welfare of dogs undergoing routine CNVR procedures at a veterinary training facility in Goa, India and to assess the impact of a targeted staff training intervention by comparing welfare assessment scores before and after its implementation. A score-based protocol was designed, incorporating 22 animal-, resource-, and management-based parameters covering six key steps of the CNVR procedure: catching/transport; cage/holding area; pre-operative period; surgery; post-operative period; and release. Eighty-two dogs were assessed initially. Areas for improvement were identified and informed the design of a targeted staff training intervention involving theory-based lectures and interactive sessions. Knowledge was assessed before and after receiving the intervention, with total scores on the assessment improving. The welfare assessment was repeated on another 81 dogs. Total welfare scores for individual dogs improved significantly after the staff intervention compared with before. This study demonstrates that a welfare assessment tool can be used to assess the welfare of individual dogs in a busy CNVR programme; furthermore, it can inform the compilation and delivery of a targeted staff training intervention and demonstrate improvements in dog welfare after such an intervention.

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus causing a debilitating febrile illness with rheumatic disease symptoms of arthralgia and arthritis. Since its spread outside of Africa in 2005, it continues to cause outbreaks and disseminates into new territories. Intervention strategies are urgently required, including vaccination and antiviral approaches. To test efficacy, the use of small animal models is required. Two mouse strains, A129, with a deficiency in their type-I interferon (IFN) receptor, and C57BL/6 are widely used. A direct comparison of these strains alongside the wild-type parental strain of the A129 mice, 129Sv/Ev, was undertaken to assess clinical disease progression, viral loads in key tissues, histological changes and levels of sera biomarkers. Our results confirm the severe disease course in A129 mice which was not observed in the parental 129Sv/Ev strain. Of the two wild-type strains, viral loads were higher in 129Sv/Ev mice compared to C57BL/6 counterparts. Our results have established these models and parameters for the future testing of vaccines and antiviral approaches.

Background The tick-borne bunyavirus, Crimean-Congo Haemorrhagic Fever virus (CCHFV), can cause severe febrile illness in humans and has a wide geographic range that continues to expand due to tick migration. Currently, there are no licensed vaccines against CCHFV for widespread usage. Methods In this study, we describe the preclinical assessment of a chimpanzee adenoviral vectored vaccine (ChAdOx2 CCHF) which encodes the glycoprotein precursor (GPC) from CCHFV. Findings We demonstrate here that vaccination with ChAdOx2 CCHF induces both a humoral and cellular immune response in mice and 100% protection in a lethal CCHF challenge model. Delivery of the adenoviral vaccine in a heterologous vaccine regimen with a Modified Vaccinia Ankara vaccine (MVA CCHF) induces the highest levels of CCHFV-specific cell-mediated and antibody responses in mice. Histopathological examination and viral load analysis of the tissues of ChAdOx2 CCHF immunised mice reveals an absence of both microscopic changes and viral antigen associated with CCHF infection, further demonstrating protection against disease. Interpretation There is the continued need for an effective vaccine against CCHFV to protect humans from lethal haemorrhagic disease. Our findings support further development of the ChAd platform expressing the CCHFV GPC to seek an effective vaccine against CCHFV.

Tuberculosis (TB) remains a very significant infectious disease worldwide. New vaccines and therapies are needed, even more crucially with the increase of multi-drug resistant Mycobacterium tuberculosis strains. Preclinical animal models are very valuable for the development of these new disease control strategies. Guinea pigs are one of the best models of TB, sharing many features with the pathology observed in human TB. Here we describe the development of TB lesions in a guinea pig model of infection. We characterise the granulomatous lesions in four developmental stages (I–IV), using histopathological analysis and immunohistochemical (IHC) techniques to study macrophages, T cells, B cells and granulocytes. The granulomas in the guinea pigs start as aggregations of macrophages and few heterophils, evolving to larger lesions showing central caseous necrosis with mineralisation and abundant acid-fast bacilli, surrounded by a rim of macrophages and lymphocytes in the outer layers of the granuloma. Multinucleated giant cells are very rare and fibrotic capsules are not formed in this animal model.

Research in human tuberculosis (TB) is limited by the availability of human tissues from patients, which is often altered by therapy and treatment. Thus, the use of animal models is a key tool in increasing our understanding of the pathogenesis, disease progression and preclinical evaluation of new therapies and vaccines. The granuloma is the hallmark lesion of pulmonary tuberculosis, regardless of the species or animal model used. Although animal models may not fully replicate all the histopathological characteristics observed in natural, human TB disease, each one brings its own attributes which enable researchers to answer specific questions regarding TB immunopathogenesis. This review delves into the pulmonary pathology induced by Mycobacterium tuberculosis complex (MTBC) bacteria in different animal models (non-human primates, rodents, guinea pigs, rabbits, cattle, goats, and others) and compares how they relate to the pulmonary disease described in humans. Although the described models have demonstrated some histopathological features in common with human pulmonary TB, these data should be considered carefully in the context of this disease. Further research is necessary to establish the most appropriate model for the study of TB, and to carry out a standard characterisation and score of pulmonary lesions.

Tuberculosis remains a major health threat globally and a more effective vaccine than the current Bacillus Calmette Guerin (BCG) is required, either to replace or boost it. The Spore-FP1 mucosal vaccine candidate is based on the fusion protein of Ag85B-Acr-HBHA/heparin-binding domain, adsorbed on the surface of inactivated Bacillus subtilis spores. The candidate conferred significant protection against Mycobacterium. tuberculosis challenge in naïve guinea pigs and markedly improved protection in the lungs and spleens of animals primed with BCG. We then immunized rhesus macaques with BCG intradermally, and subsequently boosted with one intradermal and one aerosol dose of Spore-FP1, prior to challenge with low dose aerosolized M. tuberculosis Erdman strain. Following vaccination, animals did not show any adverse reactions and displayed higher antigen specific cellular and antibody immune responses compared to BCG alone but this did not translate into significant improvement in disease pathology or bacterial burden in the organs.

The development of new therapies against SARS-CoV-2 is required to extend the toolkit of intervention strategies to combat the global pandemic. In this study, hyperimmune plasma from sheep immunised with whole spike SARS-CoV-2 recombinant protein has been used to generate candidate products. In addition to purified IgG, we have refined candidate therapies by removing non-specific IgG via affinity binding along with fragmentation to eliminate the Fc region to create F(ab′) 2 fragments. These preparations were evaluated for in vitro activity and demonstrated to be strongly neutralising against a range of SARS-CoV-2 strains, including Omicron B2.2. In addition, their protection against disease manifestations and viral loads were assessed using a hamster SARS-CoV-2 infection model. Results demonstrated protective effects of both IgG and F(ab′) 2 , with the latter requiring sequential dosing to maintain in vivo activity due to rapid clearance from the circulation.

India has a large, free-roaming dog population, encompassing both owned and stray dogs. Canine surgical neutering is often a central component of dog population management and rabies control initiatives. The provision of practical, surgical training opportunities remains a major challenge for veterinary educational establishments worldwide to ensure competency in this routine procedure. A 12-day educational programme, focusing on surgical neutering skills, was developed to address this need. A questionnaire comprising 26 questions covering surgical and clinical topics, and a self-assessment of confidence in undertaking five common surgical procedures, was completed immediately before and after finishing the programme. A total of 296 participants attended, with 228 achieving the inclusion criteria for the study. Total knowledge scores increased significantly after the training programme (mean score pre-18.94, 95% CI 18.13-19.74; post-28.11, 95% CI 27.44-28.77, p < 0.05) with improvements seen in all categories (surgical principles, anaesthesia, antibiotic use and wound management). After accounting for other participants' characteristics, scores increased, on average, by 9 points after training. Being female was associated with significantly higher overall scores, while compared to younger and older age groups, those aged 25-34 were associated with lower overall scores. Amongst those with post-graduate qualifications, overall scores increased with age. Furthermore, there was an increase in self-rated confidence by participants in undertaking all five procedures. This study demonstrates that a targeted training programme can improve veterinary participants' knowledge and confidence in canine surgical neutering and may provide an effective way to develop surgical expertise amongst veterinarians engaged in dog population management initiatives.

The mutation profile of the SARS-CoV-2 Omicron (lineage BA.1) variant posed a concern for naturally acquired and vaccine-induced immunity. We investigated the ability of prior infection with an early SARS-CoV-2 ancestral isolate (Australia/VIC01/2020, VIC01) to protect against disease caused by BA.1. We established that BA.1 infection in naïve Syrian hamsters resulted in a less severe disease than a comparable dose of the ancestral virus, with fewer clinical signs including less weight loss. We present data to show that these clinical observations were almost absent in convalescent hamsters challenged with the same dose of BA.1 50 days after an initial infection with ancestral virus. These data provide evidence that convalescent immunity against ancestral SARS-CoV-2 is protective against BA.1 in the Syrian hamster model of infection. Comparison with published pre-clinical and clinical data supports consistency of the model and its predictive value for the outcome in humans. Further, the ability to detect protection against the less severe disease caused by BA.1 demonstrates continued value of the Syrian hamster model for evaluation of BA.1-specific countermeasures.

Rift Valley fever virus (RVFV) is a mosquito-borne zoonotic pathogen causing disease in livestock and humans. Whilst initially restricted to the African continent, recent spread to the Arabian Peninsula has highlighted the likelihood of entry into new regions. Due to the absence of a regulatory-approved human vaccine, work is ongoing to develop and assess countermeasures. As such, small animal models play a pivotal role in providing information on disease pathogenesis and elucidating which intervention strategies confer protection. To develop and establish the BALB/c mouse model, we challenged mice with RVFV grown from two separate cell lines: one derived from mosquitoes (C6/36) and the other mammalian derived (Vero E6). Following infection, we assessed the clinical course of disease progression at days 1 and 3 post-challenge and evaluated viral tropism and immune analytes. The results demonstrated that RVFV infection was affected by the cell line used to propagate the challenge virus, with those grown in insect cells resulting in a more rapid disease progression. The lowest dose that caused uniform severe disease remained the same across both virus preparations. In addition, to demonstrate reproducibility, the lowest dose was used for a subsequent infection study using male and female animals. The results further demonstrated that male mice succumbed to infection more rapidly than their female counterparts. Our results establish an RVFV mouse model and key parameters that affect the course of disease progression in BALB/c mice.

Antibodies against SARS-CoV-2 are important to generate protective immunity, with convalescent plasma one of the first therapies approved. An alternative source of polyclonal antibodies suitable for upscaling would be more amendable to regulatory approval and widespread use. In this study, sheep were immunised with SARS-CoV-2 whole spike protein or one of the subunit proteins: S1 and S2. Once substantial antibody titres were generated, plasma was collected and samples pooled for each antigen. Non-specific antibodies were removed via affinity-purification to yield candidate products for testing in a hamster model of SARS-CoV-2 infection. Affinity-purified polyclonal antibodies to whole spike, S1 and S2 proteins were evaluated for in vitro for neutralising activity against SARS-CoV-2 Wuhan-like virus (Australia/VIC01/2020) and a recent variant of concern, B.1.1.529 BA.1 (Omicron), antibody-binding, complement fixation and phagocytosis assays were also performed. All antibody preparations demonstrated an effect against SARS-CoV-2 disease in the hamster model of challenge, with those raised against the S2 subunit providing the most promise. A rapid, cost-effective therapy for COVID-19 was developed which provides a source of highly active immunoglobulin specific to SARS-CoV-2 with multi-functional activity.

Innovative cross-over study designs were explored in non-human primate (NHP) studies to determine the value of this approach for the evaluation of drug efficacy against tuberculosis (TB). Firstly, the pharmacokinetics (PK) of each of the drugs Isoniazid (H), Rifampicin (R), Pyrazinamide (Z) and Ethambutol (E), that are standardly used for the treatment of tuberculosis, was established in the blood of macaques after oral dosing as a monotherapy or in combination. Two studies were conducted to evaluate the pharmacokinetics and pharmacodynamics of different drug combinations using cross-over designs. The first employed a balanced, three-period Pigeon design with an extra period; this ensured that treatment by period interactions and carry-over could be detected comparing the treatments HR, HZ and HRZ using H37Rv as the challenge strain of Mycobacterium tuberculosis (M. tb). Although the design accounted for considerable variability between animals, the three regimens evaluated could not be distinguished using any of the alternative endpoints assessed. However, the degree of pathology achieved using H37Rv in the model during this study was less than expected. Based on these findings, a second experiment using a classical AB/BA design comparing HE with HRZ was conducted using the M. tb Erdman strain. More extensive pathology was observed, and differences in computerized tomography (CT) scores and bacteriology counts in the lungs were detected, although due to the small group sizes, clearer differences were not distinguished. Type 1 T helper (Th1) cell response profiles were characterized using the IFN-γ ELISPOT assay and revealed differences between drug treatments that corresponded to decreases in disease burden. Therefore, the studies performed support the utility of the NHP model for the determination of PK/PD of TB drugs, although further work is required to optimize the use of cross-over study designs.

The COVID-19 pandemic is entering a new era with the approval of many SARS-CoV-2 vaccines. In spite of the restoration of an almost normal way of life thanks to the immune protection elicited by these innovative vaccines, we are still facing high viral circulation, with a significant number of deaths. To further explore alternative vaccination platforms, we developed COVID-eVax-a genetic vaccine based on plasmid DNA encoding the RBD domain of the SARS-CoV-2 spike protein. Here, we describe the correlation between immune responses and the evolution of viral infection in ferrets infected with the live virus. We demonstrate COVID-eVax immunogenicity as means of antibody response and, above all, a significant T-cell response, thus proving the critical role of T-cell immunity, in addition to the neutralizing antibody activity, in controlling viral spread.

The tuberculosis vaccine, Bacille Calmette-Guerin (BCG), also affords protection against non-tuberculous diseases attributable to heterologous immune mechanisms such as trained innate immunity, activation of non-conventional T-cells, and cross-reactive adaptive immunity. Aerosol vaccine delivery can target immune responses toward the primary site of infection for a respiratory pathogen. Therefore, we hypothesised that aerosol delivery of BCG would enhance cross-protective action against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and be a deployable intervention against coronavirus disease 2019 (COVID-19). Immune parameters were monitored in vaccinated and unvaccinated rhesus macaques for 28 days following aerosol BCG vaccination. High-dose SARS-CoV-2 challenge was applied by intranasal and intrabronchial instillation and animals culled 6–8 days later for assessment of viral, disease, and immunological parameters. Mycobacteria-specific cell-mediated immune responses were detected following aerosol BCG vaccination, but SARS-CoV-2-specific cellular- and antibody-mediated immunity was only measured following challenge. Early secretion of cytokine and chemokine markers associated with the innate cellular and adaptive antiviral immune response was detected following SARS-CoV-2 challenge in vaccinated animals, at concentrations that exceeded titres measured in unvaccinated macaques. Classical CD14+ monocytes and Vδ2 γδ T-cells quantified by whole-blood immunophenotyping increased rapidly in vaccinated animals following SARS-CoV-2 challenge, indicating a priming of innate immune cells and non-conventional T-cell populations. However, viral RNA quantified in nasal and pharyngeal swabs, bronchoalveolar lavage (BAL), and tissue samples collected at necropsy was equivalent in vaccinated and unvaccinated animals, and in-life CT imaging and histopathology scoring applied to pulmonary tissue sections indicated that the disease induced by SARS-CoV-2 challenge was comparable between vaccinated and unvaccinated groups. Hence, aerosol BCG vaccination did not induce, or enhance the induction of, SARS-CoV-2 cross-reactive adaptive cellular or humoral immunity, although an influence of BCG vaccination on the subsequent immune response to SARS-CoV-2 challenge was apparent in immune signatures indicative of trained innate immune mechanisms and primed unconventional T-cell populations. Nevertheless, aerosol BCG vaccination did not enhance the initial clearance of virus, nor reduce the occurrence of early disease pathology after high dose SARS-CoV-2 challenge. However, the heterologous immune mechanisms primed by BCG vaccination could contribute to the moderation of COVID-19 disease severity in more susceptible species following natural infection.