Rachael Tarlinton

(1) Background: Transboundary notifiable infectious viral diseases, such as lumpy skin disease (LSD), highly pathogenic avian influenza (HPAI), and foot-and-mouth disease (FMD), continue to severely disrupt Europe’s animal health and welfare, food security, and the multi-burdened livestock sector. (2) Methods: Through an extensive literature search, with data collected from the scientific literature, outbreak notifications, and European Union (EU) policy reports, this study synthesises evidence on the economic and societal impacts of preventive mass vaccination compared with stamping out for listed viral animal diseases in Europe. (3) Results: Evidence from LSD, HPAI, and FMD indicates that preventive vaccination reduces outbreak size, duration, and associated economic losses, particularly in high-risk and endemic settings. For LSD, vaccination is essential in eradication, as culling alone fails. For HPAI, evolving epidemiology supports vaccination-to-live strategies. In contrast, for FMD, despite epidemiological benefits of vaccination, the maintenance of FMD-free status without vaccination remains the dominant policy objective, constraining adoption of vaccination-to-live due to trade implications. (4) Conclusions: Overall, findings support the following recommendations: shifting toward preventive vaccination tailored by country and disease, prioritising vaccine-to-live strategies within a harmonised regulatory framework, and strengthening differentiating infected from vaccinated animals (DIVA)-based surveillance and trade-compatible frameworks, all sensible approaches to protect animal welfare and economic stability in Europe’s livestock sector.

Feline leukemia virus (FeLV) is widespread in domestic cats and frequently spills over into wild felid populations, causing severe outbreaks in nondomestic felid populations. Domestic cats carry both endogenous FeLV (enFeLV) and exogenous variants of FeLV (exFeLV), which can recombine to generate novel variants with alternate receptor usage. In contrast, most nondomestic felids, including the guigna, do not harbor enFeLV. This study applied amplification of the FeLV envelope gene combined with Illumina sequencing to characterize FeLV envelope gene diversity and transmission dynamics in guignas ( Leopardus guigna ), a small wild felid native to Chile and Argentina. Seven polymerase chain reaction (PCR )amplicons from five free-ranging guignas were sequenced. Illumina sequencing was successfully conducted, and subsequent phylogenetic analysis indicated that the detected infections were most closely related to strains circulating in Chilean domestic cats. However, a distinct guigna-specific cluster with unique sequence variations was identified, suggesting that FeLV transmission also occurs among guignas independent of domestic cats. Phylogenetic analysis showed that all guigna sequences formed a Chile-specific FeLV clade, closely related to domestic cat viruses but clearly separated from international FeLV-A strains.

Background: Feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) are retroviruses that affect cat longevity and health. This study aimed to assess the impact of retroviral status on life expectancy in a feline sanctuary population, which includes cats with behavioural issues and retroviral infections. Method: A retrospective cohort analysis was conducted on 132 cats, including 22 uninfected, 82 FIV ⁺ , 24 FeLV ⁺ and four FeLV/FIV ⁺ individuals. Lifetime clinical records were analysed, lifespan analysis estimates were calculated using Kaplan‒Meier analysis and common clinical conditions were assessed. Results: The median life expectancies were 160.3 months for uninfected cats, 149.1 months for FIV ⁺ , 41.5 months for FeLV ⁺ and 74.2 months for FeLV/FIV ⁺ . Both FeLV and FIV infections significantly reduced longevity ( p < 0.001 for FeLV and p = 0.037 for FIV), although this reduction was less marked for FIV. Neoplasia, especially lymphoma (76.9%), was strongly associated with FeLV ( p < 0.001), and oral disease was significantly linked to FIV ( p = 0.004). Limitations: The study is limited by the low number of animals, particularly in the FeLV/FIV ⁺ and uninfected cohorts. Statistical analysis of these groups should therefore be considered with caution. Conclusion: FeLV infection markedly shortens lifespan and increases the risk of lymphoma, whereas FIV‐infected cats are less likely to live to extremely old age.

Hedgehogs have been recently identified as carriers of Betacoronavirus erinacei (also known as Erinaceus coronavirus, EriCoV) a virus closely related to B. cameli responsible for human Middle East Respiratory Syndrome (MERS), raising questions about the risk of hedgehog-to-human transmission and suggesting the need for coronavirus (CoV) surveillance in hedgehogs. This study investigated the presence of CoVs in fecal samples of hedgehogs kept as pets in Italy in 2021-2022. A pan-CoV nested RT-PCR targeting the RdRp gene was used for screening and positive samples were sequenced and phylogenetically analyzed. Two (6.2%) out of 30 hedgehogs analyzed were positive for B. erinacei represented by 2/3 (66.7%) long eared hedgehog (Hemiechinus auritus) while all the 27 tested African pygmy hedgehog (Atelerix albiventris) were negative. Whole genome sequence obtained from one B. erinacei-positive sample showed closest homology (85.7%) with B. erinacei previously detected in Erinaceus sp. from Eastern Russia. Phylogeny showed that the virus of this study formed a separate clade in the cluster with other B. erinacei identified in Europe and European Russia and did not cluster with other B. erinacei identified in China in Amur hedgehog (E. amurensis). No recombination events were observed. Analysis of the Spike protein revealed the presence of six out of the 11 key receptor binding residues, including two out of the three critical residues recently identified for the binding of Erinaceus europaeus receptor APN and B. erinacei. Results of this study suggest the presence of a long-eared hedgehog-specific strain of B. erinacei. Overall results support the circulation of coronaviruses along a phylogenetic continuum among different species of hedgehogs and geographic locations, suggesting the need for further CoV surveillance in both domestic and wild animals. There is also a need for studies on the affinity of EriCoV with the H. auritus APN specific receptor to confirm its involvement in the viral entry process.

Retroviruses commonly cause neoplasia in many species but have not been described in guinea pigs. While historical evidence exists for the presence of an active retrovirus in domestic guinea pigs ( Cavia porcella), there has been no description of the sequence of these viruses or their role in disease in guinea pigs. This paper uses genome mining of the published domestic and wild ( Cavia aperea) guinea pig genomes for retroviral sequences to identify the gamma and beta-retroviral complement of the Cavia genome, describing eight groups of viruses with evidence of recombination between virus groups. The most intact group, gamma-like retroviruses related to HERV-T (integration estimates of 855,000 to 3.8 million years ago), has five near full length loci that are likely capable of active infection. RNA-Scope In-situ Hybridisation of archived formalin-fixed, paraffin embedded (FFPE) guinea pig lymphoma sections with a probe for one of these loci demonstrated viral RNA expression in lymphoma tissue, strengthening the case for a role of these viruses in the high incidence of leukaemia and lymphoma in this species.

Retroviruses that colonize the host germline can be passed on as inherited genetic variants. The koala ( Phascolarctos cinereus ) is currently experiencing germline colonization by two retroviruses, the koala retrovirus (KoRV) and phaCin-β. We analyze the integration site segregation and diversity of endogenous KoRV, phaCin-β, and the related phaCin-β-like in 111 pedigreed koalas from the San Diego Zoo Wildlife Alliance and seven European Zoos. The use of multigenerational pedigrees and the inclusion of health information for each individual koala reveal elimination of retroviruses from proto-oncogenes and the generation and spread of new germline integrations. Seven-hundred-and-fourteen integrations do not persist in the living population. For the 55 triads examined, 21 unique integrations identified in individual koalas are absent in their parents. Retroviral integrations associated with leukemia, fertility, and longevity are used to estimate genetic risk scores and develop a longevity breeding index to minimize neoplasia risk in the captive koala population.

Background: The recent expansion of highly pathogenic avian influenza (HPAI) H5N1 to non‐avian species in the United States has intensified public health‐related concerns. In Great Britain, low veterinarian confidence in seeing and treating birds creates potential barriers to HPAI diagnosis and reporting. Methods: An online survey explored general practice (GP) veterinarians’ confidence in and barriers to treating avian species and understanding HPAI control measures. The Capability, Opportunity, Motivation ‐ Behaviour (COM‐B) behaviour change model was used to identify barriers to treating birds and diagnosing HPAI. Results: The survey generated 72 useable responses. Only 6% reported feeling fairly/very confident seeing birds, over 83% lacked confidence in ruling out HPAI as a differential diagnosis and 17.1% were unsure how to advise clients who suspected HPAI in their flocks. Limitations: The survey required an internet connection and some technical literacy. The sample size is relatively small and may over‐represent veterinarians who have more confidence with poultry. Conclusions: GP veterinarians play critical roles in triaging, reporting and controlling HPAI. Behaviour change frameworks such as COM‐B can facilitate the identification of interventions with the potential to address barriers to accurate HPAI diagnosis and reporting in Great Britain and beyond. However, these often require national‐level rather than (or in addition to) individual‐level action.

Feline leukaemia virus (FeLV) is distributed worldwide among domestic cats and non-domestic felids. Frequent spillover events from domestic cats to wild felids have resulted in fatal disease in individual animals and outbreaks in free-ranging populations. Domestic cats carry both endogenous FeLV (enFeLV; proviral copies of the virus in the cat genome) and exogenous variants of FeLV (exFeLV). These can recombine, producing variants with recombinant envelope genes and altered receptor usage, while non-domestic felid species, except for wildcats (Felis silvestris), do not have endogenous FeLV. This study applied amplification of the FeLV envelope gene combined with Illumina sequencing of PCR products to determine the envelope gene diversity and transmission dynamics of FeLV variants in a non-domestic species, guigna (Leopardus guigna), a small felid native to Chile and Argentina. Seven PCR amplicons from five free ranging guignas were sequenced. The Illumina contigs confirmed that the origin of infection was from Chilean domestic cats. However, a distinct guigna cluster was identified, characterised by unique variations that differentiate it from domestic cat sequences and may indicate that transmission is also occurring between guigna independent of domestic cats. Phylogenetic analysis further revealed that all guigna sequences group within a Chile-specific FeLV clade, closely related to Chilean domestic cats but clearly distinct from international FeLV-A strains. We detected 96 intra-host variants across 43 genomic sites, 64 of which were non-synonymous, including one that resulted in a premature stop codon. Some of these have previously been reported in both domestic and non-domestic species from other regions. Additionally, intrahost variation analysis revealed greater genetic diversity and a higher number of non-synonymous mutations across the env gene in guigna. Unlike the variation patterns typically observed in domestic cats, where mutations in the env gene are predominantly located in the SU region, particularly within the receptor binding domain (RBD), here, a substantial proportion of mutations in guignas were found in the TM region. The pattern of mutations, with predominance of G to A transition (62.6%), strongly suggests an influence of the APOBEC-mediated hypermutation, antiviral immune system, on guigna isolates. Although FeLV-B primers produced amplicons, no genuine FeLV-B sequences were detected, consistent with amplification of FeLV-A templates due to primer cross-reactivity. The absence of large deletions or recombination signatures also indicates that only FeLV-A like strains are currently circulating in guignas. Our findings provide evidence of intra-species transmission within guigna populations, demonstrated using Illumina sequencing, a method not commonly applied in this context. Thus, this study offers a novel perspective on the disease dynamics of transmission between domestic and non-domestic felids.

Tick-borne pathogens (TBPs) pose a significant threat to canine health in Nigeria. Despite this, there is little data on the molecular identification of ticks and TBPs of dogs in Nigeria. This study assessed the prevalence of ticks and TBPs in Nigerian dogs, along with associated risk factors. A total of 259 dogs were enrolled in the study, from which 112 adult ticks were collected. Of these, 40 were characterized by molecular barcoding confirming Rhipicephalus sanguineus (R. sanguineus, 35/40) and Haemphysalis leachi (H. leachi, 5/40) infestations. Nucleotide sequences showed high percentage similarity to R. sanguineus tropical lineage and H. leachi sequences from Chad. Point-of-care (POC) testing of 259 dogs detected antibodies to TBPs in 40.9% of blood samples, with Ehrlichia (29.7%), Anaplasma (10.8%), and Dirofilaria (0.4%) species identified. PCR assays revealed a prevalence of 58.7% for TBPs, including Ehrlichia (40.5%) and Babesia (17.4%), with 7.3% co-infected. Risk factor analysis showed that adult dogs and those infested with ticks had a higher likelihood of TBP seropositivity. Exotic breeds and dogs examined during the rainy season were more likely to test positive for TBPs via PCR. Overall, this study demonstrates the high prevalence of diverse TBPs in Nigerian dogs and suggests that dog breed may play a role in susceptibility to diseases.