Search Results (279)

Over the years, various diagnostic and surgical techniques have been developed to recognise and treat cryptorchidism in equid. This study retrospectively analysed cases of cryptorchidism referred to two centres between 2012 and 2025. Clinical data collected included species, breed, age, gender, location of retained testis, diagnostic approach, anaesthesia plan and surgical treatment, perioperative medical treatment, intra-operative complications and outcomes. A total of 37 clinical cases were included, 1/37 was a donkey and 1/37 was an intersex female. Most of the horses were three years old and belonged to western riding horse breeds. Ultrasound examination correctly identified the location of the retained testis in 87% of cases. The anaesthesia plan includes a local anaesthesia block, mainly a local injection for the infiltration of the retained testis. The laparoscopic standing flank technique was the main approach, performed in 82% of cases. Complications were encountered in 9% of cases, and the median discharge time was 2 days. In our study, Quarter Horse-type horses were overrepresented, and three horses were sons of the same Quarter Horse stallion, suggesting a genetic component in aetiology. The use of ultrasound might confirm cryptorchidism in both abdominal and inguinal locations. Standing flank laparoscopy was the most frequently chosen procedure, over recumbent laparoscopy and inguinal open orchiectomy. The outcome reported a low rate of intra-operative complications. Full article

African horse sickness (AHS) is an arthropod-borne, severe equid disease caused by African horse sickness virus (AHSV). AHSV has high mortality and is endemic to sub-Saharan Africa. It has been classified into nine distinct serotypes (AHSV-1 to AHSV-9) based on VP2 immunogenicity. The AHS outbreak in Thailand in 2020, caused by AHSV-1, marked the first occurrence of this disease in Southeast Asia. It posed a substantial threat to the security of the equine industry in the nations across the region. To ensure the emergency reserve for AHS prevention and control, the AHSV strain imported to China from abroad over 60 years ago was characterized in this study. The strain was passaged in mice and then blind-passaged in Vero cells. The plaque purification method was then used to purify the strain and obtain its cell-adapted version, named AHSV/C. Neutralization tests confirmed that the virus belongs to AHSV-1. Whole-genome sequencing revealed that AHSV/C was highly homologous to AHSV-1 isolate 1180, with over 95% homology of major antigenic protein VP2, as compared to other AHSV-1 strains, including the prevalent strain in Thailand. In the mouse models, AHSV/C exhibited no clinical signs or histopathological lesions, suggesting low virulence and safety. This research for the first time characterized the in vitro growth characteristics and viral subtypes of the AHSV in China, determined its complete whole-genome sequence, and evaluated its safety using a mouse model. It provides crucial experimental materials and scientific foundations for the development of diagnostic methods and vaccines against AHSV-1. Full article

The critically endangered African wild ass is found in low population densities and there may be as few as 600 individuals in the Danakil Desert of Ethiopia and Eritrea. An understanding of suitable habitats is important for prioritizing the conservation and management of the African wild ass. In this study, we recorded presence locations of the African wild ass and independently prepared environmental covariates to identify suitable habitats using the maximum entropy (Maxent) model. Model performances were high, with the area under the curve (AUC) values of 0.927 and 0.950 for wet and dry seasons, respectively. The predicted moderately suitable habitat area extent was greater during the wet season (15,223 km²) than during the dry season (6052 km²). Precipitation, temperature, and distance from water sources were vital variables for the wet season, while distance from water sources and distance from the settlements were important determinant covariates for the dry season. This information prioritizes where protected areas should be established for African wild ass conservation and also indicates potential new undocumented locations to guide surveys in the Danakil Desert of the Afar Region, Ethiopia. Full article

The ovary is among the earliest organs to undergo age-related degeneration, limiting the reproductive potential of elite horses and constraining the growth of the equine industry. Follicular development during estrus is a key determinant of fertility, yet the molecular mechanisms underlying its decline, particularly at the level of specific ovarian cell types, remain poorly understood in equids. Here, we constructed a single-cell transcriptomic atlas to investigate ovarian changes in Kazakh horses. Using single-cell RNA sequencing (scRNA-seq), we profiled 112,861 cells from follicle-containing and follicle-absent ovaries, identifying nine distinct ovarian cell types and their subtypes, each with distinct gene expression signatures. Functional enrichment analyses revealed cell type-specific engagement in biological pathways, including ECM–receptor interaction, PI3K-Akt signaling, and oxytocin signaling. Gene expression patterns indicated tightly regulated processes of ovarian activation and cell differentiation. Notably, stromal cells exhibited high expression of ROBO2, LOC111770199, and TMTC2, while smooth muscle cells (SMCs) were marked by elevated levels of CCL5, KLRD1, and NKG7. Moreover, cell–cell interaction analyses revealed robust signaling interactions among SMCs, endothelial cells, neurons, and proliferating (cycling) cells. Together, these findings provide a comprehensive single-cell transcriptomic map of normal and abnormal ovarian states during estrus in Kazakh horses, offering novel insights into the cellular mechanisms of follicular development and identifying potential diagnostic biomarkers and therapeutic targets for ovarian quiescence in equids. Full article

The perturbation of ER homeostasis by viral infection gives rise to the unfolded protein response (UPR), characterized by the activation of three signaling pathways. PERK, IRE1, and ATF6 have been identified as the primary mediators responsible for restoring homeostasis or leading to apoptosis in response to stress. Alphaarterivirus equid, known as equine arteritis virus (EAV), is a RNA virus with importance in the equine industry that could persist in semen and lead to abortions in pregnant mares. The present article explores the consequences of in vitro infection with the EAV Bucyrus strain on UPR. Employing RT-PCR, qPCR and Western blot, our investigation has revealed the activation of PERK and IRE1α pathways, whilst ATF6 has been suppressed. Furthermore, the p38α MAPK, caspase-12, and CHOP genes were found to be upregulated, demonstrating the induction of apoptosis. Finally, in the inhibition experiments, the PERK pathway was found to be implicated in the modulation of viral replication in the initial phases of infection. Conversely, the IRE1α pathway was identified as the predominant UPR pathway in EAV replication, as evidenced by the complete inhibition of replication observed in these experiments. Consequently, the further exploration of this UPR pathway is necessary to determine whether it can effectively suppress EAV replication. Full article

Streptococcus equi subsp. zooepidemicus (SEZ) is a bacterium that primarily affects horses but can also infect other animals and humans. In 2021–2022, two SEZ outbreaks occurred in Abruzzo, Italy: one in humans linked to unpasteurized cheese (37 cases) and another in donkeys (4 deaths). These events led researchers to investigate SEZ in horses, donkeys, and a mule in the regions of Abruzzo and Molise, focusing on antibiotic resistance and genetic traits. A total of 490 nasal and genital swabs were collected from equids and analyzed for SEZ presence, with 61 positive samples. Isolated strains underwent antimicrobial susceptibility testing to assess their resistance to various antibiotics. Genetic analysis was performed to detect antibiotic resistance and virulence genes. Multi-locus sequence typing (MLST) was used to compare SEZ strains and identify potential epidemiological links. The study found that 37.7% of SEZ strains were resistant to at least one antibiotic, with tetracycline and trimethoprim/sulfamethoxazole being the most common. Additionally, 8.2% of strains showed MDR. Genetic analysis identified resistance genes such as tet(W) and erm(B), along with virulence genes like Fbp54. No major genetic clusters were detected, but ST61 was identified, similar to the human outbreak. The presence of antibiotic-resistant SEZ highlights the importance of monitoring and controlling its spread under a One Health approach, considering human, animal, and environmental health. Full article

Equine piroplasmosis (EP), caused by Theileria equi and Babesia caballi, is a tick-borne disease posing significant threats to equine health and the horse industry worldwide. Other vector-borne blood parasites, including Anaplasma phagocytophilum, Trypanosoma spp., and Leishmania spp., can also infect horses; however, their prevalence remains poorly characterized in Türkiye. This study aimed to determine the molecular prevalence of T. equi, B. caballi, A. phagocytophilum, Trypanosoma spp., and Leishmania spp. in equids from the Western Aegean Region of Türkiye. Blood samples were collected from 388 clinically healthy equines across İzmir, Aydın, Denizli, and Muğla provinces. Species-specific PCR assays were performed, and T. equi and B. caballi were detected in 24.74% (96/388) and 12.89% (50/388) of samples, respectively, with co-infections in 3.09%. T. equi and B. caballi infections were detected in horses from all four sampled provinces—Aydın, İzmir, Denizli, and Muğla—except for B. caballi, which was not found in any samples from Muğla. No samples tested positive for A. phagocytophilum, Trypanosoma spp., or Leishmania spp. Prevalence significantly varied by province, breed, age, and sex (p < 0.05). This study demonstrates the considerable prevalence of T. equi and B. caballi in Western Türkiye, underlining the need for routine screening and vector control programs. The absence of other parasites suggests limited circulation; however, continued surveillance remains crucial to safeguard equine health and prevent disease spread. Full article

Equid herpesvirus 5 (EHV-5) comprises a group of heterogeneous viruses with a worldwide distribution. Primary infection typically occurs early in life, which is followed by latency and periodic recrudescence of the virus. The aim of this study was to determine the genetic variation of EHV-5 in individual animals over time and to determine the dynamics of EHV-5 spread among selected mare–foal pairs at three horse studs. The partial glycoprotein B (gB) gene was amplified from archival nasal swab samples. Sequences from 3–5 clones from each PCR product were compared using identity matrix, phylogeny, and median-joining haplotype networks. Overall, 328 clones were sequenced from long PCR products amplified from 84 EHV-5 PCR-positive swabs. The sequences were heterogeneous (89.4% to 100% nucleotide identity). The EHV-5 sequences from mares and their foals most often clustered separately, although similar EHV-5 sequences from the same mare–foal pair were also recovered. For some animals, the EHV-5 sequences from multiple sampling times clustered together, while sequences from other animals were distributed throughout the networks. Clones from the same PCR product were most often similar to each other, but divergent clones from the same PCR product were also apparent. In conclusion, the foals were likely to acquire EHV-5 infection from sources other than their dams, but some exchange of EHV-5 between mares and their foals also occurred. Some foals likely acquired EHV-5 from a single source, while others from multiple sources. These data contribute to our understanding of EHV-5 variability and the dynamics of infection in individual horses. Full article

Glanders is a highly contagious and often fatal zoonotic disease of equids caused by Burkholderia mallei, a pathogen of significant concern due to its potential for bioterrorism. In Brazil, glanders remains endemic, particularly among working equids in the Northeast region. Diagnostic confirmation typically involves serology, culture, and polymerase chain reaction (PCR), although false-negative PCR results have been increasingly reported. This study aimed to evaluate the diagnostic performance and analytical sensitivity of four B. mallei-specific PCR primer sets using samples from 30 seropositive equids. Microbiological cultures were obtained from various organs and swabs, followed by PCR targeting four genomic regions: fliP-IS407A(a), fliP-IS407A(b), Burk457, and Bm17. All animals were confirmed positive for B. mallei via culture, but PCR detection rates varied significantly across primer sets. The fliP-IS407A(b) primer set showed the highest sensitivity, detecting 86% of samples, while the WOAH-recommended fliP-IS407A(a) set had the lowest performance (13.4%). Analytical sensitivity assays confirmed that fliP-IS407A(b) and Bm17 primers detected DNA concentrations as low as 0.007 ng, outperforming the others. These findings suggest that certain widely used primer sets may lack sufficient sensitivity for reliable detection of B. mallei, especially in chronically infected animals with low bacterial loads. The study underscores the need for ongoing validation of molecular diagnostics to improve the detection and control of glanders in endemic regions. Full article

Castration remains a common surgical procedure in equids, yet postoperative complications such as hemorrhage, infection, and eventration persist, influencing surgical outcomes. This retrospective study introduced a novel modified semi-closed castration technique aimed at minimizing these complications. Eighty-five sexually intact mature male equids (including horses, ponies, and donkeys) underwent the described inguinal castration procedure under general anesthesia. The technique involved a carefully managed opening and subsequent secure closure of the parietal vaginal tunic, enabling direct inspection of tunic contents while reducing risks associated with fully open or closed approaches. The median surgery duration was 60 min (range, 45–95), with no intraoperative complications. Postoperatively, only two equids (2.35%) exhibited scrotal swelling, which was resolved rapidly with NSAIDs. No cases of hemorrhage, pyrexia, or infection occurred. Follow-up, conducted via owner interviews after a minimum of three months, confirmed complete recovery and primary intention healing in all patients, who returned to normal activity within two days post-surgery. Compared to previously documented complication rates ranging from 2% to 48%, the present approach demonstrates superior results. Additionally, this study proposes refining existing castration technique classifications, focusing explicitly on the vaginal tunic’s status post-procedure (open, semi-closed, closed) for clarity and consistency. This novel semi-closed inguinal technique effectively integrates inspection advantages with closed technique safety, offering significantly reduced complication rates and enhanced postoperative recovery profiles in equids undergoing castration. Full article

Equine piroplasmosis (EP) is a tick-borne disease caused by Theileria equi, Theileria haneyi and Babesia caballi. It affects equids, representing significant health and economic concerns for the equine industry. EP is endemic in Portugal, so developing and implementing preventive strategies is essential. Accessing veterinarians’ knowledge, attitudes and practices (KAP) through a survey is a suitable approach, and no such studies have been conducted in Portugal until now. A KAP survey was applied to 41 Portuguese equine vets, representing mainly the Alentejo region. The average knowledge score went from medium to high, correctly identifying the causative agents, transmission routes and clinical signs. Knowledge gaps mostly concerned the identification of T. haneyi as an agent, transplacental transmission, duration of infection and diagnostic methods. Reported practices were appropriate overall, including enhancing breeders’ awareness of the disease and its prevention. Diagnostic and treatment protocols were generally consistent with current recommendations; however, these protocols are not yet fully standardized. Our findings highlight key areas where increasing expertise is needed and could serve as a foundation for future evidence-based guidelines to improve EP control in Portugal. Full article

Gastrointestinal parasitic diseases pose significant health risks to equine populations. This study investigated the epidemiological patterns of equine gastrointestinal parasites in Xinjiang by analyzing 83 fecal samples collected from Ili (n = 62) and Urumqi (n = 21) between August and November 2024. The modified McMaster technique was employed to quantify fecal egg counts (EPG) and was complemented by morphological identification to assess infection dynamics related to geography, breed specificity, and management practices. The results demonstrated an overall infection prevalence of 66.3% (55/83), with strongyles, Parascaris equorum, and Eimeria oocysts being present. Significant geographical variation was observed, with Ili exhibiting a higher prevalence (74.2%) compared to Urumqi (42.9%). Breed susceptibility analysis revealed that there was a 94.1% prevalence in Yili horses versus 42.9% in Kazakh horses. Pasture-managed herds showed markedly higher infection rates (94.1%) than stable-based systems (50.0%). Parasite community composition was dominated by strongyles (82.1%), followed by Triodontophorus spp. (27.7%) and P. equorum (2.4%). These findings highlight severe parasitic infection risks in Xinjiang’s grazing equids, underscoring the urgency of implementing targeted anthelmintic protocols to mitigate disease transmission. Full article

Equine piroplasmosis (EP), caused by Theileria equi and Babesia caballi, is a worldwide tick-borne disease with severe economic, commercial, and sanitary implications for equids. Although diagnosis is based on direct (blood smear or PCR) or indirect (serology) methods, these techniques are expensive, laborious, and false-negative and false-positive results can be yielded. Biochemistry blood profiles are routinely performed in horses. Biochemical parameters and ratios could be a reliable complementary diagnostic tool to assist clinicians in EP diagnosis, mainly in endemic areas, or for discarding similar disorders (piro-like diseases) and prioritizing specific diagnostic testing. This study describes the changes induced by EP infection in blood biochemical parameters and common and novel biochemical ratios in horses. EP-infected horses showed increased serum total and indirect bilirubin, triglycerides, and GLDH concentrations and decreased sodium concentrations compared to non-infected animals. These findings could be linked to hemolysis, diminution of athletic performance, and liver inflammation due to oxidative stress damage. While molecular methods remain the gold standard for EP diagnosis, a complete biochemical profile and ratios could provide valuable complementary information to enhance the diagnostic accuracy of piroplasmosis in horses. Full article

This study aimed to determine the prevalence of antibodies against equine brucellosis in three distinct equid groups (farm animal, urban carthorse, and sport horse) in Western Pará, Brazil, and to identify associated risk factors. A cross-sectional study, involving 75 farms across 14 municipalities, sampled 1069 equids composed of urban carthorses and sport horses. Serum samples were tested for antibodies against Brucella spp. using the buffered acidified plate antigen (BAPA) test for screening, followed by the serum agglutination in tubes with 2-mercaptoethanol (2-ME) for confirmation. Univariate and multivariate analyses assessed associations between brucellosis and potential risk factors. Out of the 1059 equids sampled, 4.05% (95% CI: 3–5.5%) tested positive in the BAPA test. Of the 44 BAPA-positive samples, 11 were confirmed positive by 2-ME, 15 were inconclusive, and 18 were negative, yielding an animal-level prevalence of 1.03% (95% CI: 0.5–1.8%) for equine brucellosis in western Pará. Prevalence was higher in the Southwest Pará Mesoregion (p = 0.047) compared to the Lower Amazon Mesoregion. No significant associations were found with animal type, reproductive problems, animal sex, species, breed, and age group. Out of the 75 farms, 8 (10.66%) had at least one seropositive equid. Confirmed cases were identified in five municipalities (Brasil Novo, Uruará, Altamira, Rurópolis, and Itaituba). This first report of equine brucellosis in Western Pará underscores the need for enhanced surveillance and control measures to mitigate its zoonotic risk to humans and transmission to other animals. Full article

Equid anaesthetic mortality is of interest to practitioners. Data for donkey and hybrid mortality have not been specifically described. The main aim of this worldwide observational, prospective, multicentre cohort study was to report on mortality in the 7 days following a general anaesthetic or standing sedation in donkeys and hybrids. This study hypothesised that donkeys and hybrids would have higher mortalities compared to horses. Data were collected as part of the fourth Confidential Enquiry into Perioperative Equine Fatalities (CEPEF4). A total of 825 cases were included, with 757 donkeys and 68 hybrids. Overall, 616 donkeys and 56 hybrids underwent a general anaesthetic. The overall mortality rate for general anaesthesia in donkeys was 1.0% and 3.6% in hybrids. In total, 141 standing sedations were performed in donkeys and 12 in hybrids. Mortality rates for standing sedations were lower, with the donkey mortality rate as 0.7%, and no hybrid mortality was seen. The mortality for donkeys for general anaesthesia appeared similar to the horse, whilst hybrid mortality was higher. COLIC vs. NON-COLIC DEATHs and EUTHANASIAs were also examined in the study. Mortality for standing sedations was lower compared to general anaesthesia. However, the numbers are too low to draw definitive conclusions; further investigation is required. Full article