Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Infectious Disease
Infectious diseases in horses encompass a range of illnesses caused by bacteria, viruses, fungi, or parasites. These diseases can affect various systems within the equine body, leading to symptoms that range from mild discomfort to severe systemic illness. Common infectious diseases in horses include equine influenza, strangles, equine herpesvirus, and West Nile virus. These diseases can be transmitted through direct contact with infected animals, contaminated surfaces, or vectors such as insects. Understanding the mechanisms of transmission, pathogenesis, and immune response is essential for effective prevention and control. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, diagnosis, treatment, and management of infectious diseases in horses.
Neutralising antibodies for Mayaro virus in Pantanal, Brazil. The Pantanal hosts diverse wildlife species and therefore is a hotspot for arbovirus studies in South America. A serosurvey for Mayaro virus (MAYV), eastern (EEEV), western (WEEV) and Venezuelan (VEEV) equine encephalitis viruses was conducted with 237 sheep, 87 free-ranging caimans and 748 equids, including 37 collected from a ranch where a neurologic disorder outbreak had been recently reported. Sera were tested for specific viral antibodies using plaque-reduction neutralisation test. From a total of 748 equids, of which 264 were immunised with vaccine composed of EEEV and WEEV and 484 had n...
Concentrations of faecal coliforms, Escherichia coli, enterococci and Campylobacter spp. in equine faeces. To determine the concentration of Campylobacter spp. as well as faecal indicator bacteria; faecal coliforms, Escherichia coli and enterococci in the faeces of healthy adult horses in a sample of properties in the Canterbury region of New Zealand. Methods: The faeces of healthy adult horses (n=59), including ponies, pleasure horses and Thoroughbreds, were collected from eight properties around Christchurch, New Zealand. The faeces were analysed for concentrations of Campylobacter spp and faecal indicator bacteria; faecal coliforms, Escherichia coli and enterococci. The presence of other animals...
Characterization of nonprimate hepacivirus and construction of a functional molecular clone. Nonprimate hepacivirus (NPHV) is the closest known relative of hepatitis C virus (HCV) and its study could enrich our understanding of HCV evolution, immunity, and pathogenesis. High seropositivity is found in horses worldwide with ∼ 3% viremic. NPHV natural history and molecular virology remain largely unexplored, however. Here, we show that NPHV, like HCV, can cause persistent infection for over a decade, with high titers and negative strand RNA in the liver. NPHV is a near-universal contaminant of commercial horse sera for cell culture. The complete NPHV 3'-UTR was determined and consists...
Le virus de l’artérite virale équine : de l’épidémiologie moléculaire à l’émergence de variants pathogènes. Equine arteritis virus (EAV) is the causative agent of equine viral arteritis, a disease observed only in equids. EAV is the prototype of the family Arteriviridæ within the order Nidovirales. EAV is an enveloped, positive-sense, single-stranded RNA virus with a considerable variation in the genome as observed in other RNA viruses. During natural infections, EAV may cause abortion and persistent subclinical infections in stallions which can shed the virus in the semen for years, or even lifetime. Chronically infected stallions represent the natural reservoir of the virus. They ensure the persi...
Skin malformations in a neonatal foal tested homozygous positive for Warmblood Fragile Foal Syndrome. Skin malformations that resembled manifestations of Ehlers-Danlos-Syndrome were described in a variety of domestic animals during the last century as cutis hyperelastica, hyperelastosis cutis, dermatosparaxis, dermal/collagen dysplasia, dermal/cutaneous asthenia or Ehlers-Danlos-like syndrome/s. In 2007, the mutation responsible for Hereditary Equine Regional Dermal Asthenia (HERDA) in Quarter Horses was discovered. Several case reports are available for similar malformations in other breeds than Quarter Horses (Draught Horses, Arabians, and Thoroughbreds) including four case reports for Warmb...
Update on viral diseases of the equine respiratory tract. Many viral agents have been associated with respiratory disease of the horse. The most important viral causes of respiratory disease in horses are equine influenza and the equine alphaherpesviruses. Agents such as equine viral arteritis virus, African horse sickness virus, and Hendra virus establish systemic infections. Clinical signs of disease resulting from infection with these agents can manifest as respiratory disease, but the respiratory tract is not the major body system affected by these viruses. Treatment of viral respiratory disease is generally limited to supportive therapies, where...
Antiserum from mice vaccinated with modified vaccinia Ankara virus expressing African horse sickness virus (AHSV) VP2 provides protection when it is administered 48h before, or 48h after challenge. Previous studies show that a recombinant modified vaccinia Ankara (MVA) virus expressing VP2 of AHSV serotype 4 (MVA-VP2) induced virus neutralising antibodies in horses and protected interferon alpha receptor gene knock-out mice (IFNAR -/-) against challenge. Follow up experiments indicated that passive transfer of antiserum, from MVA-VP2 immune donors to recipient mice 1h before challenge, conferred complete clinical protection and significantly reduced viraemia. These studies have been extended to determine the protective effect of MVA-VP2 vaccine-induced antiserum, when administered 48h be...
Potentially novel Ehrlichia species in horses, Nicaragua. Ehrlichia sp. DNA was amplified from 4 Ehrlichia-seroreactive horses from Mérida, Nicaragua. Sequencing of 16S rDNA, sodB, and groEL genes indicated that the bacterium is most likely a novel Ehrlichia species. The tick vector and the potential for canine and human infection remain unknown.
Outbreak of henipavirus infection, Philippines, 2014. During 2014, henipavirus infection caused severe illness among humans and horses in southern Philippines; fatality rates among humans were high. Horse-to-human and human-to-human transmission occurred. The most likely source of horse infection was fruit bats. Ongoing surveillance is needed for rapid diagnosis, risk factor investigation, control measure implementation, and further virus characterization.
Trends in antimicrobial resistance in equine bacterial isolates: 1999-2012. This study aimed to identify changing antimicrobial resistance patterns in isolates commonly obtained from equine clinical submissions. Laboratory records from 1999 to 2012 were searched for equine samples from which Escherichia coli or Streptococcus species was isolated. Susceptibility to enrofloxacin, ceftiofur, gentamicin, penicillin G, trimethoprim sulfamethoxazole (TMPS) and tetracyclines was noted. Isolates were divided into those identified between 1999 and 2004 (Early) and between 2007 and 2012 (Late). The proportion of isolates resistant to each antimicrobial and multiple drug-resista...
Validation and evaluation of VapA-specific IgG and IgG subclass enzyme-linked immunosorbent assays (ELISAs) to identify foals with Rhodococcus equi pneumonia. Rhodococcus equi (Rhodococcus hoagii/Prescottella equi) is a common cause of foal pneumonia, but its diagnosis remains a challenge for equine veterinarians. While the VapA-specific (virulence-associated protein A) immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) has low sensitivity and specificity for detecting pneumonic foals, little is known about VapA-specific IgG subclasses. Objective: To evaluate the performance of VapA-specific ELISA for IgG and its subclasses IgGa, IgGb and IgG(T) in the early diagnosis of pneumonia caused by R. equi. Methods: Assay validation follow...
Virological and serological investigation of Equid herpesvirus 1 infection in New Zealand. Infection with equid herpesvirus 1 (EHV-1) may be asymptomatic, or may result in respiratory disease, abortion, neonatal death, or neurological disease. The aim of this study was to estimate the prevalence of EHV-1 infection, including differentiation between genotypes with aspartic acid (D) and asparagine (N) at position 752 of the DNA polymerase sequence, within a selected population of New Zealand horses. The second aim was to determine the predictive value of serology for detection of latently infected horses. Retropharyngeal lymph nodes (RLN) and trigeminal ganglia (TG) were dissected fro...
Rickettsial Infection in Animals, Humans and Ticks in Paulicéia, Brazil. A previous study in Paulicéia Municipality, south-eastern Brazil, reported 9.7% of the Amblyomma triste ticks to be infected by Rickettsia parkeri, a bacterial pathogen that causes spotted fever in humans. These A. triste ticks were shown to be associated with marsh areas, where the marsh deer Blastocerus dichotomus is a primary host for this tick species. During 2008-2009, blood serum samples were collected from 140 horses, 41 dogs, 5 opossums (Didelphis albiventris) and 26 humans in farms from Pauliceia Municipality. Ticks were collected from these animals, from vegetation and from addition...
Update on fungal respiratory disease in horses. Fungal respiratory disease is a rare occurrence in horses. Fungal organisms are ubiquitous in the equine environment; however, there is a geographic predisposition for disease development, with fungal respiratory infections seen more commonly by practitioners working in tropical or subtropical environments. Diagnosis and treatment of fungal respiratory infections pose a challenge for the equine practitioner, and the prognosis for complete resolution of infection is often guarded; however, new antifungal medications are likely to improve treatment success. This article summarizes the available ...
Theileria equi isolates vary in susceptibility to imidocarb dipropionate but demonstrate uniform in vitro susceptibility to a bumped kinase inhibitor. The apicomplexan hemoparasite Theileria equi is a causative agent of equine piroplasmosis, eradicated from the United States in 1988. However, recent outbreaks have sparked renewed interest in treatment options for infected horses. Imidocarb dipropionate is the current drug of choice, however variation in clinical response to therapy has been observed. Methods: We quantified the in vitro susceptibility of two T. equi isolates and a lab generated variant to both imidocarb dipropionate and a bumped kinase inhibitor compound 1294. We also evaluated the capacity of in vitro imidocarb dipropionate ...
Biology of Trypanosoma (Trypanozoon) evansi in experimental heterologous mammalian hosts. Trypanosoma (Trypanozoon) evansi is a causative agent of the dreadful mammalian disease trypanosomiasis or 'Surra' and carried as a latent parasite in domestic cattle but occasionally proves fatal when transmitted to horses and camel. Sporadic outbreak of 'Surra' to different animals (beside their natural hosts) reminds that T. evansi may be zoonotic, as their close relative cause sleeping sickness to human being. This haemoflagellate is mechanically transmitted by horse fly and its effect on different host varies depending on certain factors including the effectiveness of transmission by mech...
Microsporidia and Cryptosporidium in horses and donkeys in Algeria: detection of a novel Cryptosporidium hominis subtype family (Ik) in a horse. A total of 219 and 124 individual fecal samples of horses and donkeys, respectively, were screened for the presence of Cryptosporidium spp., Encephalitozoon spp., and Enterocytozoon bieneusi DNA by genus-specific nested PCR. Isolates were genotyped by sequence analysis of SSU rRNA, GP60, TRAP-C1, COWP, and HSP70 loci in Cryptosporidium, and the ITS region in microsporidia. Cryptosporidium spp. was detected on 3/18 horse farms and 1/15 farms where donkeys were kept. Overall, five (2.3%) horse and two (1.6%) donkey specimens were PCR positive for Cryptosporidium. Genotyping at SSU and GP60 loci ...
Update on Streptococcus equi subsp equi infections. There are few diseases that ignite as much fervor among horse owners as strangles. Streptococcus equi subsp equi (strangles) infections frequently require the treating veterinarian to manage not only the clinical cases but also the biosecurity and provision of information to all involved parties. Although the disease is typically characterized by low mortality and high morbidity, restrictions of horse movement that result from appropriate quarantine procedures often frustrate the involved parties. The aims of this article are to provide clinically relevant information for diagnosis, treatment,...
Update on bacterial pneumonia in the foal and weanling. Bacterial pneumonia is a common cause of disease in both neonatal and weanling foals. The causal organism or organisms differ with the age of the foal, should be identified via microbiologic culture, and will ultimately dictate appropriate treatment. Initial treatment in neonates should be broad spectrum and bactericidal, whereas weanling age foals may receive more targeted treatment. The combination of a macrolide antibiotic and rifampin remains the gold standard for treatment of Rhodococcus equi pneumonia; however, resistance to these antimicrobials is a concern.
Molecular characterization of equine rotaviruses isolated in Europe in 2013: implications for vaccination. Equine group A rotavirus (RVAs) mainly cause disease in foals under the age of 3 months. Only sporadic data are available on the circulation of RVAs in equine populations in Europe. In this study, 65 diarrheic samples from foals under 4 months of age were collected in Belgium (n=32), Germany (n=17), Slovenia (n=5), Sweden (n=4), Hungary (n=3), Italy (n=2), France (n=1) and The Netherlands (n=1). Forty percent of these samples (n=26) were found to be RVA positive by a quantitative RT-PCR assay. The viral load in 11 of these samples was sufficiently high to be (partially) genotyped. G3, G14 and ...
Detection of equine herpesvirus in horses with idiopathic keratoconjunctivitis and comparison of three sampling techniques. To determine the role of equine herpesvirus (EHV) in idiopathic keratoconjunctivitis in horses and to determine whether sample collection method affects detection of EHV DNA by quantitative polymerase chain reaction (qPCR). Methods: Twelve horses with idiopathic keratoconjunctivitis and six horses without signs of ophthalmic disease. Methods: Conjunctival swabs, corneal scrapings, and conjunctival biopsies were collected from 18 horses: 12 clinical cases with idiopathic keratoconjunctivitis and six euthanized controls. In horses with both eyes involved, the samples were taken from the eye judg...
Cloning and nucleotide sequence analyses of 11 genome segments of two American and one British equine rotavirus strains. Group A equine rotavirus (ERV) is the main cause of diarrhea in foals and causes severe economic loss due to morbidity and mortality on stud farming worldwide. Molecular evolution of equine rotaviruses remains understudies. In this study, whole-genomic analysis of 2 group A ERV, FI-14 (G3P[12]), H-2 (G3P[12]) isolated from American, and FI23 (G14P[12]) from British was carried out and genotype constellations were determined as G3-P[12]-I6-R2-C2-M3-A10-N2-T3-E2-H7 for FI-14; G14-P[12]-I2-R2-C2-M3-A10-N2-T3-E2-H7 for FI23; and G3-P[12]-I6-R2-C2-M3-A10-N2-T3-E2-H7 for H-2, respectively. With the ...
Vaccination with a live multi-gene deletion strain protects horses against virulent challenge with Streptococcus equi. Strangles, caused by Streptococcus equi subspecies equi (S. equi) is one of the most frequently diagnosed infectious diseases of horses and there remains a significant need to develop new preventative vaccines. We generated a live vaccine strain of S. equi containing deletions in six genes: sagA, hasA, aroB, pyrC, seM and recA, which was administered to nine Welsh mountain ponies via the intramuscular route. Four vaccinated ponies developed adverse reactions following the first vaccination from which the live vaccine strain was isolated. Two of these ponies were withdrawn from the study and se...
Demographics of natural oral infection of mosquitos by Venezuelan equine encephalitis virus. The within-host diversity of virus populations can be drastically limited during between-host transmission, with primary infection of hosts representing a major constraint to diversity maintenance. However, there is an extreme paucity of quantitative data on the demographic changes experienced by virus populations during primary infection. Here, the multiplicity of cellular infection (MOI) and population bottlenecks were quantified during primary mosquito infection by Venezuelan equine encephalitis virus, an arbovirus causing neurological disease in humans and equids.
Voluntary surveillance program for equine influenza virus in the United States from 2010 to 2013. Recent surveillance studies for equine respiratory viruses have shown that equine influenza virus (EIV) continues to be a prevalent respiratory virus of equids throughout the United States and Europe. Objective: To gain a better understanding of the prevalence and epidemiology of EIV shed by horses, mules and donkeys in the United States from March 2010 to November 2013. Methods: 2,605 equids. Methods: Nasal secretions from index cases with acute onset of respiratory disease were tested by qPCR for EIV. Multilevel logistic regression was used to model the association between EIV status and pre...
Pathways for entry of livestock arboviruses into Great Britain: assessing the strength of evidence. The emergence of bluetongue virus and Schmallenberg virus in Great Britain (GB) during the last decade has highlighted the need for understanding the relative importance of the various pathways of the entry of livestock arboviruses so as to help focus surveillance and mitigation. This study summarizes what is known for the main routes of entry and assesses the strength of the current evidence for and against. Entry through infected arthropod vectors is considered at the level of each life cycle stage for tick-, biting midge- and mosquito-borne viruses, and while there is evidence that this cou...
Detection of Theileria equi and Babesia caballi using microscopic and molecular methods in horses in suburb of Urmia, Iran. Equine piroplasmosis is a severe disease of horses caused by the intra-erythrocyte protozoan, Theileria equi and Babesia caballi. The aim of this study was to identify equine piroplasmosis based on molecular and morphometrical features in horses in suburb of Urmia, West Azerbaijan province, Iran. From April to September 2011, a total number of 240 blood samples were collected randomly from horses of 25 villages. The specimens were transferred to the laboratory and the blood smears stained with Geimsa, and the morphological and biometrical data of parasite in any infected erythrocyte were consi...
Vector ecology of equine piroplasmosis. Equine piroplasmosis is a disease of Equidae, including horses, donkeys, mules, and zebras, caused by either of two protozoan parasites, Theileria equi or Babesia caballi. These parasites are biologically transmitted between hosts via tick vectors, and although they have inherent differences they are categorized together because they cause similar pathology and have similar morphologies, life cycles, and vector relationships. To complete their life cycle, these parasites must undergo a complex series of developmental events, including sexual-stage development in their tick vectors. Consequentl...
The development of equine immunity: Current knowledge on immunology in the young horse. The development of equine immunity from the fetus to adulthood is complex. The foal's immune response and the immune mechanisms that they are equipped with, along with changes over the first months of life until the immune system becomes adult-like, are only partially understood. While several innate immune responses seem to be fully functional from birth, the onset of adaptive immune response is delayed. For some adaptive immune parameters, such as immunoglobin (Ig)G1, IgG3, IgG5 and IgA antibodies, the immune response starts before or at birth and matures within 3 months of life. Other antib...
