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.
A novel oral immunotherapy strategy using transgenic barley induces Culicoides allergen-specific immune responses in horses. Insect bite hypersensitivity (IBH) is a seasonal, IgE-mediated allergic dermatitis of horses caused by salivary gland proteins of biting midges ( spp.). Current management relies on relief of clinical signs and on physical protection. In a previous pilot study, healthy horses were fed transgenic barley expressing a allergen via a special spiral bit, which successfully induced allergen-specific antibody responses. Building on this concept, the present study aimed to evaluate a more practical feeding approach, delivering transgenic barley expressing the major allergen Cul o 2p in a feed-compat...
Advances in ELISA-based detection of equine leptospirosis. Leptospirosis is a globally distributed zoonosis that affects both humans and animals, with being the main causative agent. In horses, the disease is associated with considerable economic losses. The Microscopic Agglutination Test (MAT) is the reference test for diagnosis but has limitations, emphasizing the need for effective diagnostic alternatives. In this study, was evaluated the use of a recombinant chimera, composed of ErpY-like and LemA proteins, as an antigen for ELISA-based detection of equine leptospirosis. The chimera was successfully expressed, purified and tested on 915 horse ser...
A Novel Equine F[ab’]2 Veterinary Antivenom for North American Viperid Snake Envenomation Demonstrates Efficacy by Rapid Serum Venom Removal and Improvement in Snakebite Severity Score. To assess the efficacy of a new equine F[ab'] antivenom (US Department of Agriculture code 6101.05) in removing serum venom and lowering the snakebite severity score (SSS) in animals suffering from naturally occurring viperid envenomation. Methods: Retrospective study, April 2020 to October 2021. Methods: Veterinary hospitals across four North American regions. Methods: Twenty-two dogs, one cat, and one horse. Methods: All patients received the new antivenom intravenously and were assessed for clinical response. Most dogs required one vial for clinical control of signs. Results: Among the dogs...
Seroepidemiological survey of Rhodococcus equi infection in adult horses in Mongolia. ELISA antibody titers against Rhodococcus equi strain ATCC 6939 were measured in serum samples collected from 644 horses aged 1-21 years at 13 provinces and the capital of Mongolia, of which 631 (98%) samples showed values of approximately zero. The mean antibody titers in the 14 areas ranged from -0.08 to -0.01. Nine samples (1.4%) exhibited titers of 0.1-0.2, and surprisingly, four horses (0.6%) each aged 2, 5, 8, and 9 years demonstrated positive values in the range of 0.3-0.8. Considering the age resistance characteristic of this disease, the positive horses were hypothesized to exhibit no...
Treatment evaluation using ultrasonographic scanning of the spleen in Arabian horses affected by babesiosis. Equine babesiosis is a widespread protozoan disease in Saudi Arabia. The most common finding of clinical babesiosis is splenomegaly, which can be detected using non-invasive splenic ultrasonography. Unassigned: This study aimed to investigate changes in the spleen size in horses infected with babesiosis using ultrasonography before and after treatment. Unassigned: This study employed 15 male and female Arabian horses. Each animal was examined clinically for clinical signs, and blood samples were collected in plain tubes to detect antibodies against . The spleens of healthy and affected horses ...
Characterization of the lambda light chain repertoire and non-coding regions of equine immunoglobulins using the EquCab3 genome. Horse immunoglobulins have been utilized for over a century in serotherapy to treat venomous animal bites and various other conditions. However, molecular-level information about these immunoglobulins remains limited, particularly regarding immunoglobulin lambda light chains (Igλ), which constitute over 90 % of circulating antibodies. Despite the sequencing of the equine genome, the International ImMunoGeneTics information system (IMGT) has not yet annotated Igλ in its database, restricting the analysis of the horse antibody repertoire. In this study, we analyzed the equine Igλ repertoire...
Identification of Antibodies to Chondrocyte and Synoviocyte Antigens in Equine Osteoarthritis. Innate immune responses within the joint are now known to play a key role in osteoarthritis (OA) pathogenesis. However, comparatively little is known regarding the role of adaptive immune responses in OA, and whether they may be important for initiating and sustaining progressive low-level joint inflammation. Therefore, we evaluated spontaneous osteoarthritis in horses to investigate whether antibodies recognizing live joint cells (chondrocytes, synoviocytes) were present in blood or synovial fluid, and to identify possible cellular target antigens. We found that horses with advanced OA had an...
First serological evidence of equine coronavirus and severe acute respiratory syndrome coronavirus 2 in horses in North Africa. Viral diseases cause significant economic losses within the equine population. Horses are susceptible to equine coronavirus (ECoV) and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), although only ECoV has been associated to clinical disease. The aim of this study was to investigate, for the first time in Algeria, the seroprevalence of ECoV and SARS-CoV-2 antibodies and the prevalence of ECoV infection in horses. In 2022, a total of 299 serum samples was collected from horses aged 1 to 27 years. Serological analysis for the presence of ECoV and SARS-CoV-2 was performed using a va...
Analysis of IgG responses to Sarcocystis neurona in horses with equine protozoal myeloencephalitis (EPM) suggests a Th1-biased immune response. Equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona is one of the most important neurological diseases of horses in the Americas. While seroprevalence of S. neurona in horses is high, clinical manifestation of EPM occurs in less than 1 % of infected horses. Antemortem diagnosis has proven challenging as serum antibodies against S. neurona are an indicator of infection but not necessarily disease. Factors governing the occurrence of EPM are largely unknown, although horse immunity might contribute to EPM pathogenesis. Immunoglobulin G is the predominant antibody class in eq...
A study of the epidemiology of Anoplocephala perfoliata infection in horses and the oribatid mite vector in southern England. Anoplocephala perfoliata is the most common equine tapeworm infection. This parasite is found at the small/large intestinal junction and has been associated with colic. The cestode has an indirect lifecycle involving oribatid mite intermediate hosts, though little is known of its epidemiology. This study aimed to monitor seasonal fluctuations in pasture oribatid mite numbers and the presence of Anoplocephala spp. DNA in mite samples collected from three equine premises in the UK. Exposure to infection in resident horses was assessed by measuring tapeworm-specific salivary antibodies. The data ...
Vaccination against Hendra virus of previously unvaccinated mares and their foals demonstrates the effectiveness of the current prime and boost vaccination schedule for foals. Hendra virus (HeV) is a high consequence pathogen that causes severe respiratory and/or neurological disease in both horses and humans with high mortality. The equine vaccine, Equivac® HeV, is a recombinant soluble version of the G glycoprotein of HeV (HeV-sG) that elicits a potent HeV-neutralising antibody response in adult horses and also provides indirect protection for humans. Maternally derived HeV-G specific antibodies could interfere with subsequent foal vaccination, although other factors such as foal age and the suitability of vaccination protocols that have been optimised for adult ...
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...
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...
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...
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 ...
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...
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...