Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Virus
The study of viral infections that affect equine species assesses the relationship between viruses and horses. Infections can lead to a range of clinical symptoms and may impact the health and performance of horses. Common equine viruses include Equine Influenza Virus, Equine Herpesvirus, and West Nile Virus, among others. Understanding the mechanisms of viral transmission, pathogenesis, and host immune responses is essential for developing effective prevention and treatment strategies. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, molecular biology, and clinical management of viral infections in horses.
Evaluation of mosquito transmission of equine hepacivirus in laboratory and field studies. Equine hepacivirus (EqHV) is a hepatotropic virus, closely related to human hepatitis C virus (HCV), that can cause acute or chronic infection in horses. As with HCV, transmission is thought to occur primarily through parenteral, particularly blood-borne, routes. Vertical transmission from mare to foal has been reported but appears to be uncommon. The high seroprevalence in horse populations and the occurrence of infection in isolated horses indicate efficient horizontal transmission routes exist. One such possibility is biological or mechanical transmission by arthropods, such as mosquitoes, ...
Phylogenetic and phylogeographic analysis of equine influenza in Colombia. In 2022, Colombia experienced an outbreak of equine influenza (EI) that primarily affected competition horses. Despite the epidemiological relevance of equine influenza virus (EIV) in the country, no previous phylogenetic or phylogeographic analyses based on complete genomes have been reported. Objective: To perform phylogenetic and phylogeographic analyses of complete EIV genomes obtained from horses with clinical signs in two Colombian regions between 2020 and 2023. Methods: Molecular epidemiological study based on whole-genome sequencing and evolutionary analyses. Methods: Nasopharyngeal sa...
Equine herpesvirus myeloencephalopathy-associated mutations in equine herpesvirus 1 DNA polymerase confer the ability to replicate at elevated temperatures. Equine herpesvirus myeloencephalopathy (EHM), caused by equine herpesvirus type 1 (EHV-1), poses a major threat to the equine industry because of its devastating impact on animal welfare and athletic performance. A single-nucleotide polymorphism (SNP), G2254, in ORF30 (UL30), which encodes the viral DNA polymerase, has been used as a marker of neuropathogenic EHV-1 strains, although its contribution to EHM pathogenesis remains controversial. In addition, other ORF30 SNPs have been reported in association with EHM, but their functional significance is unclear. Clinical observations indicate tha...
An experimental multiplex PCR/RT-PCR for detection of the main viruses associated with equine neurological disease. Viral neurological infections are important causes of morbidity and mortality in horses worldwide. Herein, we describe an end-point multiplex PCR/RT-PCR for simultaneous and differential detection of major equine encephalitis-related agents: rabies virus (RABV), equine herpesvirus type 1 (EHV-1), alphaviruses [Venezuelan equine encephalitis virus (VEEV), Eastern equine encephalitis virus (EEEV), Western equine encephalitis virus (WEEV) and Madariaga virus (MADV)] and flaviviruses [West Nile virus (WNV), Saint Louis encephalitis virus (SLEV), Rocio virus (ROCV) and Japanese encephalitis virus (...
Equine Sarcoid: From BPV-Driven Oncogenesis to Host-Sustained Tumor Persistence. Equine sarcoid is the most common cutaneous neoplasm of equids and represents a distinctive model of virus-associated tumor persistence. Although bovine papillomaviruses, particularly BPV-1 and BPV-2, are recognized as the main etiological agents, viral infection alone does not fully explain the clinical heterogeneity, frequent recurrence, and limited spontaneous regression of these lesions. This review summarizes current evidence on the molecular and cellular mechanisms underlying equine sarcoid pathogenesis, with emphasis on the interaction between BPV infection, host signaling pathways, tum...
Whole-genome characterization and phylogenetic analysis of Equine Rotavirus A isolated from Jeju Island, Korea. Equine Rotavirus A (ERVA) is a major cause of acute diarrhea in neonatal foals, leading to significant economic losses. Genetic variation and global transmission complicate disease control efforts. Objective: To analyze the complete genome of an ERVA strain from Jeju Island, Korea, and assess its genetic and phylogenetic relationships with global ERVA strains. Methods: Twenty-five fecal and swab samples were collected from diarrheic horses in Jeju during spring and summer 2025. Samples were screened using antigen testing and RT-PCR. One PCR-positive, antigen-test-positive sample was selected f...
Increasing Seroprevalence In Horses Evidences Widespread Circulation Of West Nile Virus In Albania. West Nile virus (WNV) is a zoonotic mosquito-borne flavivirus that causes West Nile disease, an emerging and re-emerging infection of major global importance. Horses are an important sentinel species for monitoring WNV circulation. Since viraemia in horses is brief and viral loads in the blood are low, serological assays are the primary tools used to monitor WNV exposure. This study aimed to estimate the seroprevalence of WNV antibodies in horses in Albania. Between 2017 and 2020, 509 serum samples were collected from apparently healthy, unvaccinated horses across different regions of the coun...
Nucleic acid detection and molecular traceability of equine herpesvirus 1 in imported horses. Equid alphaherpesvirus 1 is a major pathogen threatening the global equine industry, causing respiratory disease, abortion, and neurological disease. Unassigned: In April 2024, during routine pathogen screening of a batch of imported quarantine horses from the Netherlands, four out of 20 nasal swab samples tested positive for EHV-1 nucleic acid. Unassigned: The affected horses exhibited only mild respiratory signs. ORF30 SNP typing at nucleotide position 2254 and Sanger sequencing confirmed that all positive samples belonged to the N752 non-neuropathogenic genotype. As virus isolation was unsu...
First Molecular Survey of Equine Adenovirus Type 1 Infection Among Horses in Poland. Equine adenovirus type 1 (EAdV-1) infection has been recognised among horses worldwide. The virus predominantly targets respiratory tract but has also been recovered from other body systems. The objective of the study was to determine the frequency of EAdV-1 infection among selected horse populations in Poland and to estimate genetic variability within the viruses obtained. A quantitative PCR assay targeting a partial gene was used to screen 1150 nasal swabs collected from 1145 horses from 19 horse studs throughout Poland. The samples were collected opportunistically between 2012 and 2025. A ...
Molecular detection of African horse sickness virus from selected areas in Ethiopia. Equines are vital to global economies and support millions of livelihoods. However, their productivity and welfare are severely hindered by infectious diseases such as African Horse Sickness, which causes major socio-economic losses in Ethiopia. A cross-sectional study was conducted from November 2022 to May 2023 to isolate and detect African horse sickness virus in equines across epidemic areas of Ethiopia. In total, 30 blood samples and 2 tissue representative specimens were aseptically collected from clinically sick and recently dead animals and transported under cold chain to the National ...
Recombinant EHV-1 Vector Expressing Immunodominant Hemagglutinin Protein of Equine Influenza Virus H3N8 (Sub-Lineage Florida Clade 2). Equine herpesvirus type 1 (EHV-1) and equine influenza virus (EIV) are major respiratory pathogens in horses, causing significant economic losses in domesticated horses. Bacterial Artificial Chromosome (BAC) technology can be used to precisely manipulate the EHV-1 genome for the development of live-attenuated vector vaccines. Earlier, our group developed a live-attenuated EHV-1 vaccine by deleting virulence-associated genes using this technology and the mutant EHV-1 has been exploited for expressing foreign gene in the current study. Specifically, in this study, a mutant EHV-1 virus expressing...
Preliminary Assessment on Pathogenicity of an African Horse Sickness Virus Serotype 1 Strain in Guinea Pigs and Horses. African horse sickness (AHS), a noncontagious insect-borne disease affecting equids, is caused by the African horse sickness virus (AHSV) and is associated with extremely high morbidity and mortality. AHSV has nine distinct serotypes (AHSV-1 to AHSV-9). In a previous study, we characterized the genome and in vitro growth properties of AHSV/C, a cell-adapted derivative of an AHSV-1 strain imported into China 60 years ago, and verified its safety in mice. This study preliminarily explored the pathogenicity of AHSV/C in guinea pigs and horses (its natural host). Six groups of guinea pigs were ino...
Alphavirus madariaga-associated encephalomyelitis in equines from the Brazilian Pantanal reveals arbovirus circulation in a peri-urban environment. Alphavirus madariaga (MADV), a member of the eastern equine encephalitis virus complex, is an emerging arbovirus in South America, with limited information regarding its occurrence and molecular characterization in equine populations. This study reports the detection and genetic characterization of MADV in equines from the state of Mato Grosso, Brazil. Two horses presenting acute neurological disease with a clinical course of approximately two days were evaluated. Histopathological examination revealed nonsuppurative meningoencephalomyelitis. Molecular screening for neurotropic viruses using T...
Surveillance on African Horse Sickness Virus in China’s Southern Border Regions. African horse sickness (AHS) is a vector-borne and noncontagious disease caused by African horse sickness virus (AHSV) that poses a severe threat to the global equine industry. As a country historically free from AHS, China faces elevated risks due to recent outbreaks in Southeast Asia in 2020 and its ecological suitability of its border regions for AHSV vectors. Therefore, we conducted consecutive molecular and serological surveillance for AHSV in high-risk border regions from 2020 to 2024. A total of 3203 equine serum samples, 2909 whole-blood samples, and 1037 collections of blood-sucking...
Cutaneous Equine Sarcoidosis: A Case Series and Investigation Into a Potential Association With Equine Gammaherpesviruses-2 and -5 in 30 Equids. Gammaherpesviruses have been associated with granulomatous inflammation in the skin of various species. Equine sarcoidosis (idiopathic granulomatous disease) can cause granulomatous dermatitis, and its cause remains unknown. Objective: This retrospective study aimed to investigate the possible association between equine gammaherpesviruses-2 and -5 (EHV-2, -5) and cutaneous equine sarcoidosis (cES). Methods: Thirty client-owned equids. Methods: All animals had histologically and clinically confirmed cES. Signalment, geographical location and clinical features were recorded. Gram, Ziehl-Nielsen ...
[New drugs for horses and production animals in 2025]. In 2025, no novel pharmaceutical agents for horses and farm animals were introduced to the German veterinary drug market; however, the use of 2 existing active ingredients was expanded to include additional animal species. A dexamethasone preparation is now approved for use in goats, and a new product containing sodium salicylate for chickens was introduced. Oxalic acid dihydrate is now available as an impregnated strip for contact treatment. In the field of immunological veterinary medicines, a vaccine against epizootic hemorrhagic disease virus in cattle was approved for the first time. In a...
Detection of equine parapoxvirus in the stable environment during pastern dermatitis outbreak in Finland. Equine parapoxvirus (EqPPV) has emerged as a cause of recurring pastern dermatitis outbreaks in horses in Finland. First detected in 2013, EqPPV has since been associated with potentially hundreds of clinical cases and suspected zoonotic transmission. Based on serological data and field reports, EqPPV causes pastern dermatitis outbreaks in Finland every few years. This study aimed to investigate the environmental presence and plausible transmission dynamics of the virus to prepare for future outbreaks and give targeted guidelines to stable staff and veterinarians. Results: After a large-scale ...
First evidence of exposure to West Nile Virus in horses within Denmark, 2025. A nationwide serological screening of 822 horses was conducted in Autumn 2025 to investigate potential exposure to West Nile Virus (WNV) within Denmark. Serum samples were tested for antibodies against WNV, tick-borne encephalitis virus (TBEV) and Usutu virus (USUV). Four horses without any history of travel outside of Denmark, or previous vaccination against WNV, tested positive for WNV neutralising antibodies. The results support local exposure to WNV indicating that virus infected mosquitoes have been present in Denmark and underline the usefulness of horses as sentinels for the risk of hum...
Intermittent shedding dynamics of EHV-1 across biological matrices during a natural outbreak linked to international equestrian events. Equine herpesvirus type 1 (EHV-1) outbreaks associated with international equestrian events have demonstrated the capacity of this virus for rapid transboundary dissemination. However, detailed longitudinal data integrating viral shedding across multiple biological matrices within the same animals during naturally occurring outbreaks remain limited. In this study, ten horses hospitalized during a naturally occurring EHV-1 outbreak linked to an international jumping competition were monitored for 10-12 days, from which 306 nasal, ocular, urine and faecal samples were obtained and analysed by qu...
First serological evidence of circulation of equine rhinitis A virus and molecular detection of equine rhinitis B virus in horses in North Africa. Equine rhinitis A virus (ERAV) and equine rhinitis B virus (ERBV) are major respiratory pathogens of horses with a global distribution. The aim of this study was to evaluate, for the first time in Algeria, the seroprevalence of ERAV antibodies, and to investigate a wide range of equine viruses (EIV, EHV-1, EHV-4, ERAV and ERBV). A total of 298 serum samples were collected between May 2022 and October 2023, from 11 provinces. Serological analysis for the presence of ERAV was performed using the complement fixation test (CFT). Our results revealed that 16.8% (50/298) samples tested positive for ...
Viral Hepatitis. Since 2012, 2 viral causes of hepatitis have been identified in horses. Much remains to be discovered about their transmission, risk factors for clinical disease, diagnosis, and treatment approaches. Equine parvovirus-hepatitis has been identified as the cause of acute hepatic necrosis, previously known as Theiler's disease. Equine hepacivirus is recognized as a cause of chronic fibrosing hepatitis. Diagnosis relies on ruling out other causes of hepatitis and documenting infection by serum or liver polymerase chain reaction. There is no direct antiviral for either condition and treatments are ...
Molecular prevalence of equine herpesvirus type 1 and equine herpesvirus type 4 in thoroughbred and Arabian horse facilities in Türkiye. Equine herpesvirus-1 and -4 are contagious viruses causing respiratory disease and reproductive losses in horses. This study aimed to determine the prevalence of EHV-1 and EHV-4 in eight Turkish stud farms using RT-PCR analysis of nasal secretions, uterine fluids and aborted foal tissues. Deep nasal swabs were collected from 443 horses showing acute-onset fever and/or clinical signs of respiratory disease. Additionally, uterine swabs and tissue samples (lung, liver, spleen, thymus, kidney, heart) were obtained from 152 abortion cases. Among symptomatic horses, EHV-1 DNA was found in 2 cases (0...
Evaluation of two point-of-care molecular diagnostic platforms for rapid detection of equine Hendra virus. Hendra virus (HeV) is a lethal zoonotic pathogen endemic to eastern Australia, posing significant risks to equine and human health. Rapid field detection of HeV enables timely intervention and outbreak management. This study evaluated candidate point-of-care (POC) molecular diagnostic platforms for HeV detection in equine samples: including a loop-mediated isothermal amplification (DARQ RT-LAMP) assay and real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR). Comparative analytical evaluation demonstrated that RT-qPCR exhibited superior analytical sensitivity relativ...
Seroprevalence of Orthoflaviviruses in horses in 3 different Algerian climatic zones between 2021 and 2023. Orthoflaviviruses are etiological agents of neurological diseases in equines. Horses are susceptible to equine Tick-borne encephalitis virus (TBEV), Usutu virus (USUV), and West Nile virus (WNV), although mostly WNV has been associated with clinical disease. The aim of the present study was to estimate the prevalence of TBEV, USUV and WNV in 289 healthy horses from nine provinces of Algeria. This study was conducted between March 2021 and December 2023. Sera that tested positive, doubtful, or negative close to the doubtful threshold in the Orthoflavivirus-ELISA were further tested by the virus...
Isolation and Identification of Emerging Equine Encephalosis Virus Serotype 6 in Israel, 2023. Equine encephalosis (EE) is an arthropod-borne viral disease resembling a mild form of African horse sickness disease, which affects all species of equids. Previously, only EEV serotype 4 (EEV-4) caused sporadic outbreaks of the disease in Israel. In the summer of 2023, EE was clinically diagnosed in horses and donkeys in Israel. For laboratory confirmation, tissue cultures were inoculated with whole-blood samples obtained from sick animals. Five EEV isolates were successfully recovered in tissue and confirmed by conventional RT-PCR and Sanger sequencing of several viral genes. BLAST analysis ...
An epizootic of equine viral arteritis at a Thoroughbred racetrack in Illinois: 223 cases. An epizootic of equine viral arteritis (EVA) occurred over an 8-wk period in the summer of 1993 at a midwestern Thoroughbred (TB) racetrack that ceased operations in 2021. Based on clinical signs, viral isolation, and serology, 223 horses (213 TBs, 10 lead ponies) were affected. Consistent clinical signs included fever (38.3-40.6°C; 101-105°F), depression, inappetence, and diffuse urticaria, including distal limb and preputial edema. Equine arteritis virus (EAV) was cultured from buffy coat samples from 24 of 28 acutely ill horses. Seventeen of 18 convalescent horses and 1 of 92 non-affected...
Equine infectious anemia virus blocks interferon responses through Rev-mediated activation of the stress granule-PKR-eIF2α pathway. Type I interferons (IFNs) play a pivotal role in antiviral defence by inducing interferon-stimulated genes (ISGs) that target multiple stages of viral replication. Equine infectious anemia virus (EIAV) is an ancient lentivirus that establishes long-term asymptomatic infections in equids, suggesting its exceptional immune evasion capabilities. However, the mechanisms by which EIAV modulates IFN responses remain unclear. Here, we demonstrate that EIAV infection attenuates ISG expression at the post-transcriptional level. The viral Rev protein plays a central role by interacting with the stress g...
