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Cystic echinococcosis (CE) is an important cause of human morbidity and mortality worldwide, particularly in Morocco and other North African countries. We investigated the potential of three strategies to reduce Echinococcus granulosus transmission: (1) 4-monthly treatment of dogs with praziquantel, (2) vaccination of sheep with the EG95 vaccine and (3) a combination of both measures. These measures were implemented during four consecutive years in different areas of the Middle Atlas Mountains in Morocco. The outcome of the interventions was assessed through hydatid cyst (viable and non-viable) counts in liver and lungs using necropsy or in vivo ultrasound examination of the liver. A total of 402 lambs were recruited for annual vaccination with the EG95 anti-E. granulosus vaccine and 395 similar lambs were selected as non-vaccinated controls. At approximately four years of age the relative risk (estimated as odds ratio) for vaccinated sheep to have viable hydatid cysts compared with non-vaccinated controls was 3% (9.37% of the vaccinated sheep were found infected while 72.82% of the controls were infected; p = 0.002). The number of viable cysts in vaccinated animals was reduced by approximately 97% (mean counts were 0.28 and 9.18 respectively; p<0.001). An average of 595 owned dogs received 4-monthly treatment during the 44 months trial, corresponding to 91% of the owned dog population. Approximately, 5% of them were examined for E. granulosus adult worms by arecoline purge or eggs in feces (confirmed by PCR). The proportion of infected dogs significantly decreased after treatment (12% versus 35%; p<0.001). Post-treatment incidence of re-infestation corresponded to a monthly risk of 4% (95% CI: 3-6%). Treatment of owned dogs on a 4-monthly basis did not reduce the level of transmission of E. granulosus to sheep, nor did it enhance the level of control generated by vaccination of sheep with EG95, possibly because of unowned dogs and wild canids were not treated. These data suggest that vaccination of sheep with EG95 has the potential to reduce the level of CE in Morocco and in other parts of the world with similar transmission dynamics. Under the epidemiological circumstances existing in the trial area, 4-monthly treatment of owned dogs with praziquantel was insufficient to have a major impact of E. granulosus transmission to sheep.

Background Gastrointestinal nematode (GIN) infections are common in domestic sheep and impact directly and indirectly on the health of infected animals as well as on the associated economic production. In this study, we aim at summarizing the current knowledge on the influence of GIN infections on sheep production by conducting a systematic review. A subsequent meta-analysis of relevant studies was performed to provide an estimate of the effect of GIN infections on weight gain, wool production and milk yield. Methods A literature search was performed on the CAB, Pubmed and Web of Science database for the period 1960–2012. Inclusion criteria were: 1) Measurement of at least one production parameter. 2) Comparison between groups of sheep with different nematode burdens. 3) Same conditions regarding all aspects except parasite burden between groups. 4) Quantitative measurements of one or more production traits. Results Altogether, 88 studies describing 218 trials were included in this review. The majority of studies (86 %) reported that GIN infections had a negative effect on production but this was reported to be statistically significant in only 43 % of the studies. Meta-analysis indicated that performances of sheep infected with nematodes was 85, 90 and 78 % of the performance in uninfected individuals for weight gain, wool production and milk yield respectively. Our results suggest a possible reporting bias or small study effect for the estimation of the impact of GIN infections on weight gain. Finally, a general linear model provided an estimate for the decrease in weight gain in relation to the increase in faecal egg count of nematodes. Conclusion This study underlines the importance of GIN infections for sheep production and highlights the need to improve parasite management in sheep, in particular in face of challenges such as anthelmintic resistance.

Sites of persistence of bacterial pathogens contribute to disease dynamics of bacterial diseases. Footrot is a globally important bacterial disease that reduces health and productivity of sheep. It is caused by Dichelobacter nodosus , a pathogen apparently highly specialised for feet, while Fusobacterium necrophorum , a secondary pathogen in footrot is reportedly ubiquitous on pasture. Two prospective longitudinal studies were conducted to investigate the persistence of D. nodosus and F. necrophorum in sheep feet, mouths and faeces, and in soil. Molecular tools were used to detect species, strains and communities. In contrast to the existing paradigm, F. necrophorum persisted on footrot diseased feet, and in mouths and faeces; different strains were detected in feet and mouths. D. nodosus persisted in soil and on diseased, but not healthy, feet; similar strains were detected on both healthy and diseased feet of diseased sheep. We conclude that D. nodosus and F. necrophorum depend on sheep for persistence but use different strategies to persist and spread between sheep within and between flocks. Elimination of F. necrophorum would be challenging due to faecal shedding. In contrast D. nodosus could be eliminated if all footrot-affected sheep were removed and fade out of D. nodosus occurred in the environment before re-infection of a foot.

Peste des petits ruminants (PPR) is a viral disease which primarily affects small ruminants, causing significant economic losses for the livestock industry in developing countries. It is endemic in Saharan and sub-Saharan Africa, the Middle East and the Indian sub-continent. The primary hosts for peste des petits ruminants virus (PPRV) are goats and sheep; however recent models studying the pathology, disease progression and viremia of PPRV have focused primarily on goat models. This study evaluates the tissue tropism and pathogenesis of PPR following experimental infection of sheep and goats using a quantitative time-course study. Upon infection with a virulent strain of PPRV, both sheep and goats developed clinical signs and lesions typical of PPR, although sheep displayed milder clinical disease compared to goats. Tissue tropism of PPRV was evaluated by real-time RT-PCR and immunohistochemistry. Lymph nodes, lymphoid tissue and digestive tract organs were the predominant sites of virus replication. The results presented in this study provide models for the comparative evaluation of PPRV pathogenesis and tissue tropism in both sheep and goats. These models are suitable for the establishment of experimental parameters necessary for the evaluation of vaccines, as well as further studies into PPRV-host interactions.

We performed a systematic review and meta-analysis of the epidemiology, clinical and pathological features, outcomes, and therapy for listeriosis in ruminants. PubMed, Web of Science, and Scopus were searched with no publication date limits. A random-effects meta-analysis model was used to calculate the pooled effect size using morbidity and case fatality rate data. 63 and 38 studies met the inclusion criteria for the systematic review and meta-analysis, respectively. 56 out of 63 studies were published before 2016 when cgMLST was developed. A comprehensive analysis of historical data shows that the association of silage as a source of contamination in ruminants should be re-evaluated. The most common clinical presentation was encephalitis (64.8% of the animals, 1839/2837), followed by abortion (21.3% of the animals, 604/2837). The mortality rate was high despite treatment. Overall, the mean morbidity, case fatality rate, and abortion rate were 12.6%, 50.6%, and 12.8%, respectively. Meta-analysis of the subgroups revealed a Hedges' g value of −4.60 for the abortive form, indicating greater morbidity than mortality in this form. In contrast, the encephalitic form was characterized by a higher case fatality rate than morbidity (Hedges' g 9.46). Literature gaps exist since most reported outbreaks are from the twentieth century and only from a few countries. There is a lack of information on the current prevalence, consequences, and effectiveness of antimicrobial treatment of listeriosis in domestic ruminants. There is also an incomplete picture of the prevalence of Listeria infection worldwide.

Small ruminants, including sheep and goats, play an important role in the economy of American agriculture. They are susceptible to a variety of diseases that impact animal welfare and production. This study evaluated postmortem data from two different diagnostic laboratories in the state of Tennessee to discern common causes of death of small ruminants that were brought in for necropsy between 2017 to 2021. Data were prepared for analysis by selecting the predominant conditions observed at postmortem examination and risk factors including sex, age, season, and region were included in analysis. The predominant condition seen in both small ruminant species was endoparasitism. In both sheep and goats, female juvenile animals were more likely to be diagnosed with this condition at necropsy during summer months. Abortive diseases were the next most prominent condition diagnosed in both small ruminant species. The majority of these cases were due to an unknown cause and age was a significant risk factor in both sheep and goats. Neurological disorders in goats and pneumonia in sheep were included in the most prevalent diagnoses at postmortem examination with age being a significant risk factor. These findings suggest that many small ruminant deaths are attributed to infectious diseases that have herdwide implications. Producer education could be beneficial to help identify and implement control measures in a timely manner to help minimize production loss associated with common diseases.

The only genus of the Francisellaceae family known to contain species pathogenic to mammals is Francisella, for which reported cases in the Southern Hemisphere have been limited to Australia. We describe severe necrotizing and inflammatory lesions and intralesional immunohistochemical identification of Francisella sp. lipopolysaccharide among aborted ovine fetuses in Uruguay.

Introduction: Sheep associated-malignant catarrhal fever is a frequently fatal, lymphoproliferative, and vascular disease caused by ovine gammaherpesvirus 2 (OvGHV2), a member of the malignant catarrhal fever virus (MCFV) complex. OvGHV2-related epidemics normally have reduced morbidity with elevated lethality. Methodology: This study investigated the causes of elevated morbidity, mortality, and lethality in cattle maintained on Brachiaria grass pastures and with neurological and enteric disease syndromes from nine farms in Paraná, Southern Brazil. Results: The principal histopathological findings included necrotizing lymphocytic vasculitis, proliferative vascular lesions, and toxic cholangiohepatitis. An immunohistochemical (IHC) assay utilizing the 15A monoclonal antibody (15A-MAb), which is specific for MCFV, revealed positive intracytoplasmic immunoreactivity within the epithelial cells of the lungs, intestine, liver, and kidneys in most animals, confirming infections by MCFV. PCR detected singular infections by OvGHV2 (n = 3) and bovine gammaherpesvirus 6 BoGHV6 (n = 3) in cattle with positive intracytoplasmic immunoreactivity by the 15A-MAb IHC assay. In one animal with positive immunoreactivity to the 15A-MAb IHC assay, neither Macavirus was identified through molecular testing. Conclusions: These findings suggested that these two Macavirus were associated with the positive IHC findings. Additionally, the non-detection of OvGHV2 and BoGHV6 in the organs of one animal, despite typical vascular lesions and with positive IHC results, suggests that another Macavirus may be involved. Moreover, the identification of BoGHV6 DNA in cattle not infected by OvGHV2 but containing MCFV antigens, indicates cross-reactivity of BoGHV6 with the 15A-MAb assay. The possibe role of Bracharia on the occurrence of these infections is discussed.

The study aimed to evaluate the histopathological characteristics of renal lesions in chronically infected sheep and with low titers of anti-Leptospira antibodies from a slaughterhouse. In the serological analysis, 24.74% (48/194) presented seroreactivity with a titer equal to or greater than 100. Among these seroreactive sheep, titers of 100 were predominant (58.33%, 28/48), with the highest titer being 1,600 (2.08%, 1/48). Serogroup Sejroe (sv. Hardjo) was the most frequent at 35.42% (17/48). Leptospiral DNA was verified in 4.12% (8/194) of the kidney samples tested, and no urine sample was positive. All the samples corresponded to the pathogenic species L. interrogans. The eight amplicons with 202-nucleotides were identical with two mismatches (presented 100% of identity) using the PCR targeting to secY gene. Histological sections of PCR-positive kidneys were submitted to direct detection by the anti-LipL32 immunohistochemistry (IHC) technique. The Leptospira spp. antigen was evident in 62.5% (5/8) of the kidneys. Positive staining was observed in the cytoplasm of tubular cells and in the form of brownish aggregates that adhered to tubular epithelial cells and projected into the lumen. Inflammatory lymphoplasmacytic infiltrate, ranging from mild to moderate, with multifocal distribution, was the predominant finding in seroreactive animals (33.33%, 16/48). The demonstration of the leptospiral antigen lining the renal tubules through IHC of naturally infected sheep confirmed by PCR characterizes renal colonization in a species with the presence of histological changes compatible with leptospirosis.

Background Segmental axonopathy is a recessively inherited neurodegenerative disorder that has affected Merino sheep since the early 1930s. Despite its long-standing recognition, the genetic basis of the condition remained unknown. This study aimed to identify the genetic cause of segmental axonopathy and confirm its pathological features to improve diagnostic accuracy and inform breeding strategies. Results Whole genome sequencing and genotyping of affected and unaffected Merino sheep identified a novel homozygous frameshift variant in the ALS2 gene that segregated with disease. RNA sequencing of cerebellar peduncle tissue confirmed the nonsense consequence on the ALS2 transcript. Histological analysis highlighted the hallmarks of the disease as large, foamy eosinophilic axonal swellings predominantly in the trigeminal ganglia, with additional degenerative changes in both the brain and spinal cord. These findings support the value of targeted sampling of sensory roots of the trigeminal nerve, spinal cord tracts, and dorsal nerve rootlets to enhance diagnostic accuracy. The same ALS2 variant was found across multiple unrelated flocks in both Australia and New Zealand, indicating a broader presence within the fine-wool Merino sheep population. Conclusions This study identifies a novel ALS2 frameshift variant associated with segmental axonopathy in Merino sheep and provides both genetic and histological evidence supporting its role in disease pathology. The development of a DNA diagnostic test will enable more informed breeding decisions, reduce the prevalence of this condition, and improve animal welfare and productivity in the Merino industry. Moreover, the findings offer a potential large-animal model for exploring early-onset forms of human motor neuron diseases, including amyotrophic lateral sclerosis, in which ALS2 variants are implicated.