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.
Sabine M, Feilen C, Herbert L, Jones RF, Lomas SW, Love DN, Wild J.Until 1977 no case of abortion caused by equine herpesvirus 1 (EHV1) had been recorded in Australia although the virus, called equine rhinopneumonitis virus, had been known to have been present at least since 1962. Outbreaks of EHV1 abortion occurred in New South Wales in 1977 and in 1981. Sporadic cases of EHV1 abortion had been confirmed in some parts of Australia each year since 1975. It was concluded that an abortigenic subtype of EHV1 had been introduced to Australia in 1977 and that the previously endemic respiratory subtype occasionally caused abortion. Virus isolation in a variety of c...
Peel AJ, Field HE, Reid PA, Plowright RK, Broder CC, Skerratt LF, Hayman DT, Restif O, Taylor M, Martin G, Crameri G, Smith I, Baker M, Marsh GA....No abstract available
Uzal FA, Navarro MA, Asin J, Henderson EE.The clostridial diseases of horses can be divided into three major groups: enteric/enterotoxic, histotoxic, and neurotoxic. The main enteric/enterotoxic diseases include those produced by Clostridium perfringens type C and Clostridioides difficile, both of which are characterized by enterocolitis. The main histotoxic diseases are gas gangrene, Tyzzer disease, and infectious necrotic hepatitis. Gas gangrene is produced by one or more of the following microorganisms: C. perfringens type A, Clostridium septicum, Paeniclostridium sordellii, and Clostridium novyi type A, and it is characterized by ...
French RA, Meier WA, Zachary JF.Tissues from a 9-year-old American Standardbred gelding with a history of anorexia, mild colic, and unexpected death were submitted to the Laboratories of Veterinary Diagnostic Medicine at the University of Illinois for histopathologic examination. Microscopic diagnoses were severe subacute, diffuse eosinophilic colitis with intralesional protozoa and a subacute to chronic eosinophilic portal hepatitis with granuloma formation. Two tissue-invading, ciliated protozoa were identified in large numbers within the colonic mucosa. The ciliates were Polymorphella ampulla and Cycloposthium sp., Phylum...
El-Sayed SAE, Rizk MA, Baghdadi HB, Ringo AE, Sambuu G, Nugraha AB, Igarashi I.In this study, we designed novel truncated Babesia caballi (B. caballi) recombinant proteins from the previously used B. caballi proteins; 134-Kilodalton Protein (rBC134) and Merozoite Rhoptry 48 Protein (rBC48). Then, we evaluated the diagnostic performance of the newly designed proteins when used as a single antigen or when used as cocktail antigen consists of rBC134 full length (rBC134f) + newly designed rBC48 (rBC48t) or newly designed rBC134 (rBC134t) + rBC48t for the detection of B. caballi infection in horse using indirect enzyme-linked immunosorbent assay (iELISA). We used one dose and...
Birckhead EM, Das S, Tidd N, Raidal SL, Raidal SR.Septic synovitis and peritonitis are routinely diagnosed in horses based on clinical examination findings and laboratory assessment of synoviocentesis and abdominocentesis samples, respectively. Diagnosis is difficult in some cases because of an overlap in laboratory results for septic and non-septic inflammation. Neutrophil extracellular trap (NET) formation is part of the innate immune response against pathogens. Identifying and quantifying NETs, which have not been explored in clinical samples from horses with septic synovitis and peritonitis, to our knowledge, may be helpful in detecting i...
Cardo MV, Vezzani D.Targeted vector surveillance informed by data on mosquito biting patterns can help limit arboviral zoonotic diseases. To characterise host-biting networks in rural and urban equestrian facilities from temperate Argentina, adult resting mosquitoes were collected (December 2018-April 2019) with a battery-powered aspirator. Engorged females were sorted to species, and their blood source was identified using molecular techniques. Bipartite network analysis was performed for rural and urban matrices. A total of 177 bloodmeals from 11 mosquito species of Aedes and Culex were identified, with seven m...
Biberstein EL, Jang SS, Hirsh DC.A total of 268 isolates of coagulase-positive staphylococci from a variety of animal species, including dogs, horses, cats, monkeys, goats, and cows, were assigned to species on the basis of the API Staph- Ident system (Analytab Products, Inc., Plainview , N.Y.). Of 195 isolates from dogs, 179 (91.8%) were Staphylococcus intermedius, as were 9 of 25 (36%) isolates from horses, 7 of 15 (46.6%) isolates from cats, and 4 of 6 (66.6%) isolates from goats. Only 1 of 10 isolates from monkeys and none of 7 isolates from cows were S. intermedius. Of the remaining 68 cultures, 63 were identified as Sta...
Dauphin G, Legay V, Pitel PH, Zientara S.For over two centuries, Borna disease (BD) has been described as a sporadically occurring infectious meningoencephalomyelitis affecting horses and sheep in Central Europe. Over the last decade, the BD epidemiology has been discussed. Firstly, its geographical distribution seems larger than what was previously thought. Secondly, the disease can affect a large number of warm-blooded animal species, including humans. The aetiological agent is the Boma disease virus (BDV), an enveloped, nonsegmented negative-stranded RNA virus classified in the new virus family Bornaviridae (Mononegavirales order)...
Lawhon SD, Taylor A, Fajt VR.Clinical specimens from dogs, cats, and horses were examined for the presence of obligate anaerobic bacteria. Of 4,018 specimens cultured, 368 yielded 606 isolates of obligate anaerobic bacteria (248 from dogs, 50 from cats, and 308 from horses). There were 100 specimens from 94 animals from which only anaerobes were isolated (25 dogs, 8 cats, and 61 horses). The most common sites tested were abdominal fluid (dogs and cats) and intestinal contents (horses). The most common microorganism isolated from dogs, cats, and horses was Clostridium perfringens (75, 13, and101 isolates, respectively). Th...
Muniz APM, Tolesano-Pascoli G, Vieira RBK, Polli MG, Rodrigues VDS, Gonzaga HT, Mamede CCN, Da Cunha NC, Szabó MJP, Yokosawa J.Rickettsia rickettsii is the etiological agent of Rocky Mountain spotted fever, which is an important tick-borne zoonosis and, in Brazil, it causes Brazilian spotted fever, which has high lethality rate. This study aimed to evaluate a synthetic peptide corresponding to a segment of the outer membrane protein A (OmpA) as an antigen in a serological test for the diagnosis of rickettsial infections. The amino acid sequence of the peptide was selected by predicting B cell epitopes using B Cell Epitope Prediction (Immune Epitope Database and Analysis Resource) and Epitopia and OmpA sequences of Ric...
With outbreaks of equine influenza continuing to be reported in the UK, Richard Newton and Fleur Whitlock of the Animal Health Trust discusses practical steps that vets can promote and practise to reduce the risk of the virus spreading.
Romi R, Pontuale G, CIufolini MG, Fiorentini G, Marchi A, Nicoletti L, Cocchi M, Tamburro A.In the late summer of 1998, an outbreak of equine encephalomyelitis due to West Nile virus (WNV) occurred in the Tuscany region of central Italy. The disease was detected in 14 race horses from nine localities in four Provinces: Firenze, Lucca, Pisa and Pistoia. The outbreak area included Fucecchio wetlands (1800 ha), the largest inland marsh in Italy, and the adjacent hilly Cerbaie woodlands with farms breeding horses. To detect potential vectors of WNV, entomological surveys of Fucecchio and Cerbaie were undertaken during 1999-2002 by collecting mosquito larvae from breeding sites and adult ...
Stadejek T, Mittelholzer Ch, Oleksiewicz MB, Paweska J, Belák S.Equine arteritis virus (EAV) was detected by RT-nested PCR in semen samples from a naturally infected South African donkey. Sequence analysis of the amplified ORF5 fragment revealed only 60 to 70% nucleotide identity to a panel of EAV reference sequences. The unique donkey EAV sequence was also found to be stable during passage in horses. The sequence data reported in this study indicate that the South African donkey variant might represent a new genotype of EAV. The distinct genetic properties of the South African asinine strain of EAV suggest a divergent evolution of this arterivirus in vari...
Bezerra CS, Cargnelutti JF, Sauthier JT, Weiblen R, Flores EF, Alves CJ, Clementino IJ, Santos CSAB, Azevedo SS.The aim of this survey was to estimate the apparent herd-level and animal-level prevalences, as well as to identify risk factors and spatial clustering of vesicular stomatitis virus (VSV) positive herds in the state of Paraíba, semiarid of Brazil. The state was divided into three sampling strata: Sertão, Borborema and Zona da Mata/Agreste. For each sampling stratum, herd-level and animal-level prevalences were estimated by a two-stage sampling survey. First, a pre-established number of herds (primary sampling units) were randomly selected; second, within each herd, a pre-established number o...
Schmitt S, Stephan R, Huebschke E, Schaefle D, Merz A, Johler S.Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of severe infections in humans and animals worldwide. Studies elucidating the population structure, staphylococcal cassette chromosome mec types, resistance phenotypes, and virulence gene profiles of animal-associated MRSA are needed to understand spread and transmission. Objective: The objective of this study was to determine 1) clonal complexes and spa types, 2) resistance phenotypes, and 3) virulence/resistance gene profiles of MRSA isolated from animals in Switzerland. Methods: We analyzed 31 presumptive MRSA isolates co...
Gomez DE, Wong D, MacNicol J, Dembek K.The fecal bacterial microbiota of normal foals and foals with enterocolitis has been characterized using next-generation sequencing technology; however, there are no reports investigating the gut microbiota in foals hospitalized for other perinatal diseases. Objective: To describe and compare the fecal bacterial microbiota in healthy and sick foals using next-generation sequencing techniques. Methods: Hospitalized (17) and healthy foals (21). Methods: Case-control study. Fecal samples were collected from healthy and sick foals on admission. Sick foals were further divided into sick nonseptic (...
Middleton DJ, Weingartl HM.Hendra virus (HeV) and Nipah virus (NiV) form a separate genus Henipavirus within the family Paramyxoviridae, and are classified as biosafety level 4 pathogens due to their high case fatality rate following human infection and because of the lack of effective vaccines or therapy. Both viruses emerged from their natural reservoir during the last decade of the twentieth century, causing severe disease in humans, horses and swine, and infecting a number of other mammalian species. The current review summarizes our up to date understanding of pathology and pathogenesis in the natural reservoir spe...
Porphyre T, Grewar JD.African horse sickness (AHS) is a disease of equids that results in a non-tariff barrier to the trade of live equids from affected countries. AHS is endemic in South Africa except for a controlled area in the Western Cape Province (WCP) where sporadic outbreaks have occurred in the past 2 decades. There is potential that the presence of zebra populations, thought to be the natural reservoir hosts for AHS, in the WCP could maintain AHS virus circulation in the area and act as a year-round source of infection for horses. However, it remains unclear whether the epidemiology or the ecological cond...
Tanaka Y, Suganuma K, Watanabe K, Kobayashi Y.Dourine, caused by infection with Trypanosoma equiperdum, is one of the trypanosomiasis in equids. The clinical course of dourine is long-term, ranging from 1-2 months to several years. Since the pathogenesis of dourine has not yet been elucidated, experimental studies using mouse infection models are needed. Although mice are not susceptible to most T. equiperdum strains, some strains can infect mice. Even in such strains, infected mice develop rapidly transient parasitemia and die within 2-8 days. Therefore, mice experimentally infected with these T. equiperdum strains are not suitable for m...
Seyedmousavi S, Guillot J, Arné P, de Hoog GS, Mouton JW, Melchers WJ, Verweij PE.The importance of aspergillosis in humans and various animal species has increased over the last decades. Aspergillus species are found worldwide in humans and in almost all domestic animals and birds as well as in many wild species, causing a wide range of diseases from localized infections to fatal disseminated diseases, as well as allergic responses to inhaled conidia. Some prevalent forms of animal aspergillosis are invasive fatal infections in sea fan corals, stonebrood mummification in honey bees, pulmonary and air sac infection in birds, mycotic abortion and mammary gland infections in ...
Kalemkerian PB, Metz GE, Peral-García P, Lopez-Gappa J, Echeverría MG, Giovambattista G, Díaz S.We investigated the association of equine arteritis virus (EAV) infection and three short tandem repeat (STR) polymorphisms located within or in close proximity to equine lymphocyte antigen (ELA) region. We used a case-control design as a first approach before proceeding to select candidate genes. One hundred and sixty-five Silla Argentino horses were taken in 2002 from positive serological detections of EAV in Argentina, to determine whether STR genotypes were correlated to genetic susceptibility to EVA. Allele frequency distribution did not show significant differences between both groups (P...
Nichani AK, Sharma RD, Sarup S.Efficacy of medium RPMI-1640 (supplied by Gibco USA, Centron and Hi-media) supplemented with horse, donkey, sheep and goat sera was evaluated for in vitro propagation of Theileria annulata (Hisar) infected bovine mononuclear cells. The results were compared with the growth rate in RPMI-1640 supplemented with foetal bovine serum (Gibco). RPMI-1640 (Gibco) proved to be the best medium for in vitro cultivation of the parasite infected cells. Foetal bovine serum could be easily, safely and reliably substituted with goat and sheep sera in the growth medium. Horse and donkey sera also gave comparabl...
Wollstein M.The parameningococci of Dopter are culturally indistinguishable from true or normal meningococci, but serologically they exhibit differences as regards agglutination, opsonization, and complement deviation. Because of the variations and irregularities of serum reactions existing among otherwise normal strains of meningococci it does not seem either possible or desirable to separate the parameningococci into a strictly definite class. It appears desirable to consider them as constituting a special strain among meningococci not, however, wholly consistent in itself. The distinctions in serum rea...
Fairbanks EL, Baylis M, Daly JM, Tildesley MJ.African horse sickness virus (AHSV) is a vector-borne virus spread by midges (Culicoides spp.). The virus causes African horse sickness (AHS) disease in some species of equid. AHS is endemic in parts of Africa, previously emerged in Europe and in 2020 caused outbreaks for the first time in parts of Eastern Asia. Here we analyse a unique historic dataset from the 1989-1991 emergence of AHS in Morocco in a naïve population of equids. Sequential Monte Carlo and Markov chain Monte Carlo techniques are used to estimate parameters for a spatial-temporal model using a transmission kernel. These para...
Borchers K, Frölich K, Ludwig H.In blood samples of seven captive equid species from four German zoos EHV-1 specific antibodies were detected in 76% and EHV-4 specific antibodies in 73% of the 55 animals, whereas 93% were tested positive for EHV-2 and EHV-5, respectively. In only one blood sample from a Przewalski's wild horse EHV-4 DNA was amplified by PCR. From seven Przewalski's wild horses EHV-2, and from another one EHV-5 was isolated by cocultivation. The identity of the virus isolates was verified by PCR and restriction enzyme digestion.
Brees DJ, Sondhoff AH, Kluge JP, Andreasen CB, Brown CM.A 7-month-old foal was admitted to the hospital with a history of lethargy, weight loss, mild diarrhea, and anorexia. A diagnosis of proliferative enteritis caused by Lawsonia intracellularis-like organisms was made after necropsy and histologic examination of the small intestine. Although infection with L intracellularis-like organisms is a rare cause of enteritis in foals, it should be considered in the differential diagnosis, especially if the foal was housed in the proximity of pigs or pig feces. Antemortem diagnosis remains challenging because isolation of the organism in fecal material r...
