Topic:Antibodies
Antibodies in horses are specialized proteins produced by the immune system in response to foreign substances, known as antigens. These substances can include pathogens such as bacteria, viruses, and parasites. Antibodies function by recognizing and binding to specific antigens, thereby neutralizing them or marking them for destruction by other immune cells. In equine health, antibodies are integral to both natural immune responses and those induced by vaccinations. The study of antibodies in horses encompasses their production, diversity, and role in disease resistance and management. This page gathers peer-reviewed research studies and scholarly articles that explore the generation, function, and implications of antibodies in equine immunology and disease control.
The Viremic Phase and Humoral Immune Response Against African Horse Sickness Virus That Emerged in Thailand in 2020. African horse sickness (AHS), a life-threatening disease caused by African horse sickness virus serotype 1 (AHSV-1), emerged in Thailand in February 2020 with 607 cases and a 93% fatality rate. The outbreak was mitigated by vector control and a live attenuated virus (LAV) vaccine. Information regarding viremia and immunity after infection and vaccination during outbreaks are essential for controlling disease transmission. This study evaluated these parameters in 15 infected naïve horses and 11 vaccinated horses during the 2020 outbreak. Whole blood was collected and subjected to RT real-time ...
Progress in serology and molecular biology of equine parasite diagnosis: sustainable control strategies. Internal parasitic infections are a persistent challenge for horse owners, in the absence of effective vaccines and the growing challenge of drug resistance, leading many researchers to view current control strategies as unsustainable. Despite slow progress over the past two decades, effective parasitic diagnosis remains crucial for controlling infections and preventing the growing issue of drug resistance. This review examines the research progress in serological and molecular biological diagnostic methods for major equine parasites. Currently, most diagnostic techniques are based on genes su...
Adjuvant combination enhances immune response of equine influenza virus vaccine in horses. Despite routine vaccination, equine influenza outbreaks occur due to disparities of virus strains between vaccine and field, and immunity gaps between vaccinations. Objective: To evaluate whether a combination of adjuvants can enhance immune responses to equine influenza virus (EIV) vaccines. Methods: In vivo experimental study. Methods: Eight mixed-breed horses were immunised intramuscularly with a recombinant canarypox-based EIV vaccine, either alone or in combination with monophosphoryl lipid A (MPL) and polyinosinic-polycytidylic acid (poly I:C). A single vaccine dose was administered, and...
A serological test based on mutated recombinant Fasciola hepatica cathepsin L protease for the diagnosis of equine fasciolosis. Fasciola hepatica is a common trematode parasite of livestock in many regions, causing significant economic losses and affecting animal welfare. Horses rarely develop patent liver fluke infection. However, liver damage can affect animal health and welfare. Therefore, F. hepatica infection in horses may be underreported. Recently, a serological test for the antibody detection has been reported based on recombinant parasite cathepsin L1 (FhCL1) protease. Here, we optimized this enzyme-linked immunosorbent assay (ELISA) for antibody-detection in horses with equine fasciolosis based on recombinant...
Effect of Long-Term Freezing on Indirect Fluorescent Antibody Titers for the Diagnosis of Equine Protozoal Myeloencephalitis. Long-term freezing storage can alter the stability of proteins, thereby compromising accurate determination of indirect fluorescent antibody test (IFAT) titers that support the diagnosis of equine protozoal myeloencephalitis. Objective: Assess the effect of long-term storage at -80°C on IFAT against S. neurona and N. hughesi in equine serum and cerebrospinal fluid (CSF). Methods: Paired serum and CSF (n = 46), and serum only (n = 25) samples. Methods: Prospective study of samples stored 6-12, 13-18, and 19-24 months. Comparing antibody titers across time points, McNemar and Wilcoxon...
Genetic and serological analyses of equine influenza viruses isolated in Kumamoto and Hokkaido, Japan in 2025. In April and May 2025, outbreaks of equine influenza occurred for the first time in 17 years in Japan. Equine influenza virus (EIV) of the H3N8 subtype was mainly detected in heavy draft horse populations in Kumamoto Prefecture and the Tokachi area of Hokkaido. In total, 10 EIVs were isolated from infected horses and then were used for genetic and serological analyses. Phylogenetic analysis of all eight genes revealed that all Japanese isolates were clustered with the Florida sublineage clade 1 (Fc1) viruses and were closely related to North American Fc1 viruses detected in 2024-2025. The resu...
Life-threatening anaphylaxis following antivenom administration in two patients with horse dander allergy. Antivenom is used to treat systemic envenomation and is immunoglobulin G raised from animals, mainly horses, inoculated by venom. Unassigned: We report two cases of life-threatening anaphylaxis following the administration of antivenom in patients with known horse dander allergy. Unassigned: A 14-year-old boy presented with redback spider envenomation. He had a known horse dander allergy. He received antivenom to treat severe pain and developed immediate severe anaphylaxis requiring endotracheal intubation and inotropic support. A 52-year-old man with horse dander allergy presented with suspec...
Development of an In-House ELISA for Serological Detection of Equine Herpesvirus-1/4 Antibodies in Turkish Horses. Equine herpesvirus 1 (EHV-1) and Equine herpesvirus 4 (EHV-4) are major viral pathogens of horses that contribute to respiratory disease, abortion, and neurological disorders, leading to economic losses in the equine industry. Accurate serological diagnosis is critical for disease surveillance and control. This study aimed to develop and validate an in-house enzyme-linked immunosorbent assay (ELISA) for detecting antibodies against EHV-1 and EHV-4 in horse sera. Serum samples previously confirmed by virus neutralization test (VNT) and a commercial ELISA were used to optimize the assay. Cut-off...
Human Adenovirus 36 Antibodies in Horses with Different Metabolic Statuses. This study investigated the presence of antibodies to human adenovirus type 36 (HAdV-D36) in horses with different metabolic statuses, including normal, overweight, and those diagnosed with equine metabolic syndrome (EMS). A total of 151 serum samples were tested, of which 47.6% were positive for anti-HAdV-D36 antibodies. Although the horses were confirmed to be susceptible to HAdV-D36 infection, there was no significant correlation between infection and blood glucose or cholesterol levels. However, the triglyceride levels showed significant differences-they were particularly elevated in the s...
Development and application of a NP-cELISA for the detection of nucleoprotein antibodies of equine influenza virus. Equine influenza (EI), caused by the equine influenza virus (EIV), is an acute respiratory disease that has become enzootic worldwide, resulting in frequent outbreaks and substantial economic losses within the equine industry. In this study, we developed a competitive enzyme-linked immunosorbent assay (NP-cELISA) for the detection of antibodies against the EIV nucleoprotein (NP). The assay was designed by coating plates with purified monoclonal antibodies (mAbs) against the NP protein, followed by simultaneous incubation of the test serum samples and HRP-NP antigen in a competitive binding rea...
Prevalence of African Horse Sickness Virus Antibodies in Horses and Selected Wildlife in Four Geographical Regions of Nigeria. African horse sickness (AHS) is a severe, infectious arthropod-borne disease of equids caused by the AHS virus (AHSV). It is endemic in Sub-Saharan Africa, and several sporadic outbreaks of the disease have been reported in Nigeria in the past 5 decades. Following a recent outbreak of the disease in Lagos State, this study was conducted to investigate the prevalence of (AHSV) antibodies in apparently healthy horses and some selected wildlife sampled in four geographical regions of Nigeria. Using a competitive enzyme-linked immunosorbent assay, 575 serum samples collected from horses in five ...
Anti-IL-5 Vaccination Dampens Allergen-Specific IgE Levels and Modulates IL-4 and IL-5 Th2 Cytokines in Skin Allergy of Mice and Horses. Skin allergies are among the most frequent types of allergies, where continuous investigation of the pathological immune mechanisms is required for a better understanding and a more effective treatment of the disease. In this study, we aimed to investigate the effect of interleukin (IL)-5 vaccination on allergen-specific IgE antibodies as well as T cell cytokine modulation in skin allergy using a mouse model and a naturally occurring disease in horses. Methods: Ovalbumin (OVA)-sensitized mice, as well as horses affected by equine insect bite hypersensitivity (IBH) were administered an anti-IL-...
Seroprevalence of segmented flavi-like Alongshan virus in horses. The emergence of new pathogens poses a significant threat to global health, exacerbated by climate change, biodiversity loss, and increased globalization. Ticks, as vectors for various pathogens, contribute to the rising incidence of diseases. Surveillance programs are crucial for identifying and controlling emerging pathogens. This study focuses on the Alongshan virus (ALSV), a segmented flavi-like virus first identified in humans in China in 2017. Despite its ability to infect a wide range of mammals, the natural hosts and transmission pathways of ALSV remain poorly understood. Therefore, we...
Seroprevalence and Passive Clinical Surveillance of West Nile Virus in Horses from Ecological High-Risk Areas in Western Romania: Exploratory Findings from a Cross-Sectional Study. This cross-sectional study evaluated the seroprevalence and clinical impact of West Nile virus (WNV) infection in horses from three ecologically high-risk counties in western Romania (TimiÈ™, Arad, and Bihor) between 2023 and 2025. A total of 306 unvaccinated horses were tested using a commercial ELISA, with 8.17% testing positive for WNV antibodies, indicating prior exposure. Passive surveillance for clinical signs during mosquito seasons identified 16 horses with acute neurological symptoms, four of which were confirmed as clinical cases based on WNV-specific IgM positivity, suggesting proba...
Serological differentiation of West Nile, Usutu, and tick-borne encephalitis virus antibodies in birds and horses using mutant E protein ELISAs. West Nile virus (WNV), Usutu virus (USUV) and tick-borne encephalitis virus (TBEV) are worldwide endemic zoonotic orthoflaviviruses, often co-circulating in the same areas. Serological studies in animals, mostly birds and horses, are important means to monitor the spread of these viruses and the infection risks for humans. However, cross-reactive antibodies to these structurally similar flaviviruses frequently impact serological differentiation in enzyme-linked immunosorbent assays (ELISAs), hence time-consuming virus neutralization tests (VNTs) have to be employed in laboratories with high bi...
α2-Macroglobulin Concentrations in Canine and Equine Serum Donors. To determine if serum α2-macroglobulin (A2M) concentration varies based on donor species-canine or equine-and signalment. Methods: Serum A2M concentration ([A2M]) was measured in healthy dogs (n = 30) and horses (n = 31) using species-specific ELISAs. Results: Canine and equine [A2M] median (IQR; range) were 98.70 ng/mL (92.79 ng/mL; 34.33-696.18 ng/mL) and 557 000 ng/mL (437 900 ng/mL; 62 600-3 042 900 ng/mL), respectively. Equine [A2M] was significantly higher than canine [A2M]. Depending on the statistical analysis performed, sex had either no statistical (pâ€...
Detection of Antibodies Against Leptospira interrogans Serovars Among Stabled Horses in Qazvin Province of Iran as a One-Health Concern. Leptospirosis, a global zoonotic disease caused by pathogenic Leptospira spp., poses significant health risks to both animals and humans. This study aimed to assess the seroprevalence of antibodies against Leptospira interrogans serovars in stabled horses in Qazvin province, Northwest Iran. From January 2023 to April 2024, a total of 83 blood samples were collected from asymptomatic horses using the microscopic agglutination test (MAT). Results indicated a seroprevalence of 40.96% (95% CI: 31-52), with notable variations among regions: 38.89% (95% CI: 27-52) in Qazvin, 38.46% (95% CI: 18-64) i...
Long-Term Maintenance of High Neutralizing Anti-SARS-CoV-2 Antibodies Titres in Mares’ Milk and Offspring Serum After Pregnant Mares Immunization With SARS-CoV-2 Spike Protein. In this study, we aim to report the persistent presence of anti-SARS-CoV-2 immunoglobulins in pre-immunized mare offspring. Three mares from Vital Brazil Institute were pre-immunized with recombinant SARS-CoV-2 spike protein and became pregnant during this period. After parturition, the mares' serum and colostrum/milk and foal serum were collected over 6 weeks. Our results have shown high and persistent presence of IgG and neutralizing antibodies over the weeks not only in the mares' serum, as expected, but in mares' colostrum/milk and foal serum as well-what were very surprising. This peculia...
Pigments with antimicrobial and cytotoxic activities from the coprophilous fungus Fusarium solani isolated from horse dung. Four previously undescribed phenazine-derived pigments (1-4), along with seventeen known compounds, were isolated from a strain cultured on solid rice medium. Structural elucidation of the new compounds was achieved through extensive spectroscopic analysis, while known compounds were identified by comparison with literature data. The antimicrobial and cytotoxic activities of the isolated compounds were assessed. Compounds 2, 5, and 11 exhibited weak antifungal activity against at 200 μM, while compounds 5, 6, 11, 12, 15, and 20 demonstrated moderate antibacterial effects against at the sam...
A Prevalence Study on Anoplocephala spp. in Serbian Horses: Navigating Diagnostic Challenges and Understanding Infection Risks. spp. are common equine tapeworm species in Europe, frequently found in grazing horses. is the most pathogenic, clinically significant species associated with gastrointestinal disorders, particularly colic, and can have a fatal outcome in some horses. The aim of this study was to determine the infection prevalence of spp. in Serbia and to identify relevant risk factors. A total of 173 horses from various regions were tested using a combination of diagnostic methods: coprological analysis via combined sedimentation-flotation and the Mini-FLOTAC technique, as well as serological testing using ...
Seroprevalence of Equine Influenza Virus Antibodies in Horses from Four Localities in Colombia. Equine influenza is a highly contagious disease caused by the equine influenza virus (EIV). The occurrence of EIV outbreaks in America is associated with low levels of vaccination coverage. In Colombia, no seroprevalence evaluation has been carried out to estimate the distribution of the virus within the country. Our aim was to perform a sero-epidemiological survey of equine influenza infections and to identify associated risk factors in horses from four departments of Colombia. Serological testing was carried out by using an ELISA for the detection of IgG antibodies against the influenza A vi...
West Nile Virus Antibody Prevalence in Horses During the 2023 Outbreak in Tunisia, North Africa. A total of 20 horses belonging to the Pasteur Institute of Tunis used for the production of therapeutic serum antiscorpion venom were tested for the presence of antibodies anti-West Nile virus (WNV) during the 2023 outbreak of West Nile disease that affected humans and horses in Tunisia. Of the 20 samples tested in November 2023 by enzyme-linked immuno-sorbent assay (ELISA), five were positive, leading to a seroprevalence of 25%. Since the number of horses is not substantial, all samples were tested also by virus microneutralization test (MNT) using the Tunisian strain of WNV lineage 1 isolate...
High seroprevalence of Francisella tularensis with low titers in Oklahoma equids from 2021-2023 suggests widespread exposure in the state’s equine population. To determine the seroprevalence of Francisella tularensis in horses in Oklahoma and to describe factors associated with seropositivity. Unassigned: In this observational study, 238 frozen equine serum samples were tested for F tularensis by microagglutination assay (MAT). Samples were collected from 36 of 77 Oklahoma counties from 2021 through 2023. Exclusion criteria included insufficient sample quantity, cross-reactivity to Brucella abortus, and county outside of Oklahoma. The Fisher exact test was used to compare the proportion of positive tests by year, river basin, and topographic region....
Serum and mucosal antibody testing to detect viral exposure in contact horses during an equine herpesvirus myeloencephalopathy outbreak. To apply equine herpesvirus type 1 (EHV-1) antibody testing in nasal swabs and serum in nonclinical horses during a naturally occurring outbreak of (EHV-1). Previous experimental EHV-1 challenge studies showed stable serum anti-EHV-1 antibody concentrations paired with rapidly increasing nasal mucosal antibodies (mucAbs) prevent EHV-1 infection, viral shedding, and cell-associated viremia. From this, we hypothesized that EHV-1 antibody testing can confirm exposure in non-clinical horses during an outbreak. Unassigned: 2 horses with neurological signs from 1 farm were admitted to an equine hosp...
Risk Factors Associated with the Prevalence of Antibodies Against Brucellosis in Equids from Western Pará, Brazil. 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 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 an...
Development of a colloidal gold immunochromatographic strip to detect equine infectious anemia virus. Equine infectious anemia virus (EIAV) poses a significant global threat to the equine industry, resulting in considerable economic losses and compromised horse health. Given the limited treatment options available, early detection and prevention strategies are essential to combat this viral infection. In this study, we introduce a novel colloidal gold immunochromatographic (ICLF) strip for the rapid and accurate detection of EIAV antibodies. The strip incorporates a unique fusion protein, p26-gp90, designed to enhance both the specificity and sensitivity of the detection method for EIAV antibo...
Long-Term Humoral Immune Response After West Nile Virus Convalescence in Horses in a Geographic Area of Multiple Orthoflavivirus Co-Circulation. In the last three decades, West Nile virus (WNV, Flaviviridae, Orthoflavivirus genus) has become one of the most important encephalitic agents worldwide, causing substantial numbers of cases in humans and horses every year by re-emerging in endemic areas and emerging in new territories. It is considered that after natural WNV infection, humans and birds develop long-term immunoprotection, but data on immunoprotection in horses is scarce. Objective: West Nile virus infection provides long-term humoral immunity in subclinically infected horses. Methods: Client-owned, naturally WNV subclinically ...
Nebulization of an mRNA-encoded monoclonal antibody for passive immunization of foals against Rhodococcus equi. Inhalation of Rhodococcus equi causes severe pneumonia in humans and animals worldwide, most commonly affecting horse foals. The standard for preventing R. equi pneumonia in foals is transfusion of hyperimmune plasma, which is expensive and carries the risk of adverse effects. Our goal was to passively immunize foals against R. equi by nebulizing mRNA encoding an equine monoclonal antibody (mAb) against the virulence-associated protein A (VapA) directly into the lungs. VapA-specific memory B cells from an immunized horse were used to identify and select the sequence for an equine immunoglobuli...
Comparative Evaluation of a Multistrain Indirect ELISA Targeting Anti- p26 and gp45 Antibodies for EIAV Detection. Equine Infectious Anemia Virus (EIAV), a lentivirus marked by considerable genetic variability, poses significant diagnostic challenges. Existing diagnostic tools encompass the Agar Gel Immunodiffusion Assay (AGID), enzyme-linked immunosorbent assay (ELISA), and Western blotting (WB). ELISA and AGID mainly utilize the p26 capsid protein, often sourced from the Wyoming reference strain. To broaden the range of viral proteins and strains employed in these immunoassays, we previously developed a novel p26/double-strain gp45 indirect ELISA. In this study, we evaluated the performance of this ELISA...
Development and Preclinical Evaluation of a Lyophilized Vaccine Against Equine Herpesvirus Type 4 (EHV-4). Equine rhinopneumonia, caused by equine herpesvirus types 1 and 4 (EHV-1 and EHV-4), continues to be a significant health and economic concern in the global equine industry, particularly in Kazakhstan. While vaccines targeting EHV-1 are available, there is currently no licensed monovalent vaccine for EHV-4, and existing formulations offer limited protection against this serotype. This study aimed to develop and evaluate a freeze-dried, live-attenuated EHV-4 vaccine with improved safety, stability, and immunogenicity. Methods: A field isolate of EHV-4 was attenuated through serial passaging in ...