Infections in horses encompass a range of diseases caused by various pathogens, including bacteria, viruses, fungi, and parasites. These infections can affect different systems within the horse, such as the respiratory, gastrointestinal, and integumentary systems, leading to a variety of clinical signs depending on the pathogen and the severity of the infection. Common infectious diseases in horses include equine influenza, strangles, and equine herpesvirus. Diagnosis often involves clinical examination, laboratory testing, and sometimes imaging, to identify the causative agent and assess the extent of the disease. Treatment strategies may include antimicrobial therapy, supportive care, and preventive measures such as vaccination and biosecurity practices. This page aggregates peer-reviewed research studies and scholarly articles that explore the pathogenesis, diagnosis, treatment, and prevention of infectious diseases in equine populations.
Vernaccini M, de Marchi L, Bindi F, Meucci V, Sala G, Cingottini D, Sgorbini M.Antibiotics are essential in veterinary medicine, enhancing animal health and welfare. However, widespread use contributes to resistance, increasing the risk of treatment failure and the transmission to humans. Objective: Analyze antibiotic prescribing practices in an equine internal medicine unit, focusing on factors influencing use, particularly Highest Priority Critically Important Antimicrobials (HPCIAs). Methods: 1315 adult equids, including horses, donkeys and mules, presented for different diseases to the Veterinary Teaching Hospital (VTH) of the University of Pisa from 2011 to 2023. Re...
Goetz M, Cremoux M, Lassalle L, Douet JY.To assess the efficacy and safety of Rose Bengal and green light corneal cross-linking (RGX) as an adjunctive treatment for complicated corneal ulcers and stromal abscesses in horses. Methods: A retrospective analysis included 81 horses (82 eyes) treated with RGX between 2018 and 2024. Cases involved complicated corneal diseases such as melting keratitis, fungal keratitis, deep stromal defects, and stromal abscesses. Treatment consisted of topical or iontophoretic administration of 1% Rose Bengal followed by green light irradiation (550 nm; 150 J/cm) for 10 min. Most procedures (76.8%) w...
Klass LG, Krücken J, Mbedi S, Sparmann S, Schenk T, Andreotti S, von Samson-Himmelstjerna G.Mixed strongyle infections represent the most prevalent equine parasitosis and can result in life-threatening disease, especially in young horses. Species involvement and pathogenesis of this parasitosis are poorly understood, and data on foals and broodmares are notably lacking. Methods: In a longitudinal study undertaken in 2022 in Germany, individual faecal samples (n = 497) and metadata were collected for naturally infected foals and broodmares (n = 48) kept under conventional husbandry conditions. Nematode infections were detected coproscopically via the Mini-FLOTAC method. In a s...
Cooper CJ, Arroyo LG, Hammermueller JD, Botts MM, Pearl DL, Wootton SK, Lillie BN.Equine herpesvirus-1 (EHV-1) is ubiquitous in the horse population, but prevalence estimates have ranged from 3 to 88% depending on the population and method of sampling. No prevalence studies have been carried out in Ontario, Canada. The objective of this study was to measure the prevalence of EHV-1 shedding in healthy broodmares in Ontario. A total of 381 mares from 42 farms in Ontario were sampled, including pregnant and barren broodmares. Samples were collected from the nose, vagina, and blood of each mare up to 6 times from December 2016 through October 2017 using a cross-sectional study ...
Sjolin E, Espinosa D, Arroyo L, Kenney D, Lack A, Baird J.Listeriosis is caused by , a Gram-positive, facultative anaerobic, intracellular rod bacterium that can infect a wide variety of species. Listeriosis occurs in a diverse range of domestic and wild animals but is most commonly a disease of ruminants. Clinical signs include meningoencephalitis, typhlocolitis, septic arthritis, and abortions. Listeriosis in horses has been reported in several countries but is an uncommon diagnosis. This report describes clinical, bacteriological, histopathological, and immunohistochemical findings in 6 foals with neonatal septicemia from which was isolated. Key ...
Sayre KC, Flores-Ahlschwede P, Wethington AB, Kahn SK, Bray JM, Volding DM, Ahlschwede S, Bordin AI, Cohen ND, Welsh TH.Transfusion of Rhodococcus equi hyperimmune plasma (REHIP) to neonatal foals is done to reduce the incidence of rhodococcal pneumonia. Objective: To determine effects in newborn foals of REHIP transfusion on serum cortisol concentrations; the association of serum cortisol concentrations with serum globulin concentration and anti-rhodococcal immunoglobulin activity; and cumulative incidence of rhodococcal pneumonia. Methods: Serum samples were collected from 356 newborn foals from 13 New York farms immediately before and after transfusion of 1 L or 2 L of REHIP. Serum samples were assayed for c...
Cyathostomins and Anoplocephala perfoliata infect equids worldwide and both are of concern due to their potential to cause clinical disease. Although coprological techniques are commonly used for assessing helminth egg shedding these do not provide information about an individual's total parasite burden. Antibody-based tests provide information on infection levels within individuals. Objective: This study aimed to evaluate cyathostomin and Anoplocephala perfoliata occurrence in Italian horses using coprological and serum-based antibody detection methods and to analyse risk factors for infectio...
Decoster C, Lefère L, Raes E, van Loon G, Dufourni A.Leptospirosis is a widespread zoonotic, infectious disease associated with abortion, stillbirth, as well as liver and kidney failure. Leptospiral Pulmonary Haemorrhage Syndrome (LPHS) has increasingly been reported in human and canine patients infected by Leptospira and is associated with a high fatality rate. In equine medicine, pulmonary haemorrhage has mainly been described in foals with leptospiral infections, but rarely in adult horses. Objective: To characterise the clinicopathological features of pulmonary haemorrhage as a distinct disease entity in adult horses with leptospirosis, term...
Friedlund AM, Bracamonte JL, Koziy RV, Epp T, Thomas KL.To evaluate if high-volume lavage results in a negative bacterial culture of egress fluid, regardless of pathogen in an experimental model of equine septic arthritis. Methods: Experimental study. Methods: A total of 11 horses in three groups (lipopolysaccharide [LPS] Group 1, n = 4; Escherichia coli [E. coli] Group 2, n = 4; Staphylococcus aureus [S. aureus] Group 3, n = 3). Methods: A middle carpal joint of each horse was injected with LPS (synovitis Group 1), E. coli (septic arthritis Group 2) or S. aureus (septic arthritis Group 3). Arthroscopic lavage of the middle carpal joint...
Jager MC, Luethy D, Shallop S, Cathcart J, Divers TJ, Tan JY, Beasley EM, Johnson P, Leduc L, Smith C, Jamieson CA, Magdesian KG, Van de Walle GR....Equine hepacivirus (EqHV) is closely related to hepatitis C virus (HCV), which causes persistent infection and chronic hepatitis in people. Information on persistent EqHV infection and hepatitis is limited. Objective: To report 19 cases of chronic hepatitis and persistent EqHV infection. Methods: Mixed retrospective and prospective case series. Methods: Inclusion criteria were: (1) chronic hepatitis, defined as persistently increased serum liver biomarkers, increased serum liver biomarkers accompanied by histopathological evidence of chronicity, for example, fibrosis, or both; (2) positive ser...
Rossi TM, O'Sullivan TL, Greer AL.Competitions are an important source of entertainment and revenue in the horse industry but may contribute to disease introduction and spread. The objectives of this study were to, (i) describe the annual (2016 to 2018) contact networks of Equestrian Canada competitions in Ontario, Canada, and (ii) determine if the networks exhibit characteristics of 'small world' networks. Data on Equestrian Canada registered competitions in the province of Ontario, Canada between 2016 and 2018 were used to create three types of yearly contact networks: competition networks, horse networks, and venue networks...
Strompfová V, Štempelová L, Bujňáková D, Karahutová L, Gondoľová D, Nagyová M, Siegfried L.In order to develop non-antibiotic therapies to treat dermatological diseases it is urgent to spread knowledge on composition and properties of skin bacteria in healthy animals. Since horses are popular companions of humans, it is necessary to know what risk skin bacteria pose to humans. Therefore the aim of this work was to analyse species composition of staphylococci isolated from skin swabs of 50 healthy horses using MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight) spectrometry and to characterize their virulence properties. Swabs were collected from five body areas (n...
Ketphan W, Sato M, Tsujimura K, Mizutani T, Takemae H.Equine rhinitis B virus (ERBV), a member of the Picornaviridae family, is associated with mild to moderate respiratory illness in horses, yet its genomic diversity remains incompletely characterized. In this study, we performed metagenomic analysis on a rectal swab sample from a diarrheic foal confirmed to be positive for rotavirus A. Unexpectedly, we identified a highly divergent ERBV strain with a 9,448-nucleotide genome encoding a 2,721-amino-acid polyprotein. Sequence analysis revealed only 62.5-63.1% identity in the polyprotein and 47.1-49.8% in the VP1 region compared to known ERBV serot...
Raftery AG, Gummery L, Garcia K, Mohite D, Capewell P, Sutton D.Equine trypanosomiasis is a neglected protozoal disease. Objective: To answer the study question: In equines what are the effects of disease management of trypanosomiasis on disease severity (individual level) and disease prevalence (population level) compared to no intervention? Methods: Systematic review. Methods: Studies were identified that described management of naturally occurring equine trypanosomiasis in any country following 'Preferred Reporting Items for Systematic Reviews and Meta-analyses' using eight international databases (1980-2022). Risk of bias was assessed using ROBINS-I. D...
Girisgin O, Gülegen E, Girisgin AO, Cirak VY.Anoplocephalid species are responsible for causing tapeworm infection in horses. The disease may cause serious health issues, including discomfort, colic, and even intestinal perforation and death. A study was carried out to compare the detection rates of tapeworm eggs in naturally infected horses using two different examination solutions. For this purpose, faecal samples of 241 horses were examined with a combined sedimentation + centrifugation + flotation technique using saturated sugar solution (specific gravity (SG) = 1.30) as the basis and potassium carbonate (KCO) solution (S...
Pourmahdi Borujeni M, Ghobadian Diali H, Mashhadi AG, Aliabad MJ.The recent identification of novel viruses associated with hepatitis in horses has prompted equine veterinarians to investigate the viral factors contributing to equine hepatitis. Hepacivirus equi (EqHV), a member of the Flaviviridae family within the Hepacivirus genus, has been detected in horses affected by hepatitis. Globally, EqHV is highly conserved, existing as a single genotype with three distinct subtypes (Subtypes 1-3). Numerous studies have detected the virus by PCR and identified EqHV-specific antibodies through serological tests in different regions worldwide. However, to the best ...
Hiblu MA, Ahmed MO.This case report documents the first identified Brucella infection in a 6-year-old male Thoroughbred horse in Libya. The horse exhibited muscle and joint pain, inflammation over the shoulders with a pulpy texture (fistulous withers), stress, fatigue, and potential systemic infection. Its diagnosis was confirmed through serological testing, with agglutination titers of 1/80 for B. melitensis and 1/160 for B. abortus, and a blood culture revealing Gram-negative coccobacilli. After 3 weeks of combination therapy with rifampicin and doxycycline, the inflammation resolved, systemic signs disappeare...
Parker M, Arnade H, Parker JL, Gordon J, Peroni JF.Investigation of alternative antibiotic therapies is critical for the future of medicine. Platelet lysate (PL) is a blood product that has shown antibiotic potential, which could be used to augment or replace current antibiotics. Objective: To compare the effects of equine PL versus antibiotics on growth of clinically isolated antibiotic resistant bacteria. We hypothesized that PL would exert an antimicrobial effect on equine bacterial isolates resistant to antibiotics. Methods: In vitro experimental study. Platelets were collected via apheresis from nine donor horses and underwent two freeze-...
Bazan L, Argibay HD, Borges-Silva W, Pita Gondim LF, Dos Santos Mattos TA, Santana JO, da Silva EM, Begon M, Khalil H, Costa F, de Oliveira Carneiro I.Toxoplasma gondii is a globally neglected zoonotic parasite, particularly prevalent in socioeconomically vulnerable areas. Various animal species serve as reservoirs for T. gondii across different regions, including domestic cats, livestock, and a variety of wild and synanthropic animals. In urban areas, especially informal settlements, the close coexistence of humans, domestic animals, and wildlife may influence local transmission dynamics. This study evaluated the seroprevalence and associated risk factors for T. gondii infection in domestic and synanthropic animals from two low-income neigh...
Karaushi H, Yoshitake A, Kanazawa Y, Watanabe N, Tokano M, Seki M, Mitsutake K.A 69-year-old woman with hypertension had undergone total arch replacement with an open stent graft 7 years prior. She was referred to our hospital for evaluation after experiencing fever (>38 °C) and cough. Chest radiography revealed a prominent aortic arch, and contrast-enhanced computed tomography demonstrated aortic arch enlargement and peri-graft fluid collection containing air. These findings indicated graft infection and prompted immediate intervention. Blood cultures grew Streptococcus equi subspecies zooepidemicus, a zoonotic pathogen associated with horses. Notably, the patient wor...
Hoerdemann M, Sahoo DK, Allbaugh RA, Kubai MA.To assess if an inexpensive, commercially available ultraviolet C (UV-C) light device with a peak emission of 275 nm can inhibit equine keratomycosis-associated pathogens located at different corneal depths in an ex vivo model. Methods: A controlled, randomized experimental design. Aspergillus fumigatus and Fusarium solani isolates were inoculated in fresh bovine corneoscleral transplants, superficially or at 450 μm of stromal depth for the ulcerative keratomycosis or stromal abscess model, respectively. After a minimum of 18 h of incubation, treatment groups received 15 s of UV-C li...
Rask E, Righetti F, Ruiz A, Bjerketorp J, Frosth S, Frykberg L, Jacobsson K, Guss B, Flock JI, Henriques-Normark B, Hartman E, Gustafsson A....Infection of susceptible horses with subspecies (), the causative agent of strangles, is associated with commingling. Exposure may occur among horses at equestrian events, sales, or horses moved among different equine stabling environments. Strangles can affect all horses on a farm, leading to the death of up to 10% of cases depending on their immunity status at the time of infection, the development of complications, the success of biosecurity measures, and the use of vaccination. The current retrospective study used ELISAs to measure the exposure of horses to at a farm that experienced an...
Harpke M, Brangsch H, Melzer F.In Germany, Contagious Equine Metritis (CEM) is a persistent problem in equine populations. The often subclinical nature of the disease, which is caused by the bacterium Taylorella equigenitalis, poses a problem for the breeding industry. However, there is a lack of knowledge about the genomic diversity of the pathogen in Germany, as studies on the genome level are lacking. Thus, in this study we sequenced 63 T. equigenitalis isolates from a strain collection and contemporary clinical isolates from before 2007-2024. Most of these isolates came from Icelandic horses in southern Germany. Based...
Gao W, Liu M, Nurdaly K, Caidan D, Sun Y, Duan J, Zhao J, Gong X, Zhou J, Zhang Y, Chen Q.Equine bacterial abortion presents substantial economic and One Health challenges; however, comprehensive epidemiological data from China are limited. This study sought to ascertain the overall prevalence of key pathogens-namely, spp., , , and spp.-in equine populations in northwestern China. In this study, we aimed to further elucidate the characteristics of co-infections, profile antimicrobial resistance genes, and identify associated risk factors. Conducted as a cross-sectional analysis across four provinces, we collected 508 blood samples and 24 abortion tissue samples from 15 farms. Pat...
Rudeekiatthamrong A, Nguyen GT, Kamyingkird K. infection (Surra) remains a major constraint to equine health and productivity in Thailand. The only available trypanocidal drug, diminazene aceturate (DA), has limited efficacy, poor blood-brain barrier penetration, and toxicity in horses. This study aimed to investigate the inhibitory effects of commonly used equine antibiotics, gentamicin (GMC), ceftiofur (CTF), and trimethoprim-sulfamethoxazole (TS), against (Thai strain isolated from dairy cattle number 953; TEDC 953) to identify potential therapeutic alternatives or adjuncts for equine trypanosomosis. Unassigned: An growth inhibition...
Nowicka B, Łopuszyński W, Krajewska-Wędzina M, Biazik A, Sobuś M, Polkowska I, Szacawa E.Gastrointestinal mycobacteriosis in horses is difficult to diagnose because of the pathogen's intracellular nature and the non-specific clinical symptoms. Effective accurate diagnosis facilitates prognosis and treatment. Current diagnostic procedures and methods of collecting material do not permit definitive antemortem diagnosis. However, culturing, acid-fast bacilli staining, histopathology, PCR and immunological marker evaluation may prove useful. Unassigned: Three horses were admitted to a clinic for intensive care and a final diagnosis. Physical examination and additional tests were perfo...
Barua S, Tarannum A, Huber L, Easterwood LA, Velayudhan B, Da Silveira BP, Enyetornye B, Cohen ND, Dimitrov KM, Schwarz ER, Awtrey A, Groover E....Over the past decade, newly identified equine hepatotropic flavi- and parvoviruses, such as equine parvovirus-hepatitis (EqPV-H) and equine hepacivirus (EqHV), have generated considerable scientific and clinical interest. Pegiviruses, including Pegivirus (P.) caballi and P. equi, are also recognized and known to frequently cause persistent infections. However, comprehensive epidemiological data in the United States remain limited. This study analyzed 1195 equine serum samples collected from university-owned horses and diagnostic submissions across Alabama, Georgia, and Texas. Quantitative PCR ...
El-Geneady MA, Ramadan RM, Mahdy OA, Kamel MS, Salem MA.Hippobosca equina, a common ectoparasite of horses, poses a significant challenge to equine health worldwide. This study provides a molecular characterization of H. equina and examines its impact on host immune responses and oxidative stress. Genetic analysis of samples from various regions revealed notable homogeneity, indicating limited genetic variation among populations. Phylogenetic analysis demonstrated close genetic relationships among sequences from Egypt, France, Kazakhstan and Portugal, while also showing comparable but more distant identities to sequences from China, Denmark, Finlan...
Silva JG, Martins KR, Rahal NM, Schuch LFD, Cunha RC, Meireles MCA.Neorickettsia risticii, an obligate intracellular bacterium, is the causative agent of Potomac Horse Fever (PHF) - a systemic, acute, and potentially fatal diarrheal disease. This pathogen is an endosymbiont of digenetic trematodes, with freshwater snails playing a role in its biological cycle. The disease exhibits endemic and seasonal patterns, primarily affecting horses in wetlands during warmer months, and has been documented in the United States, Canada, Europe, and South America. Previous studies confirmed the pathogen's presence in herds from southern Brazil via serology and PCR; however...
Hondalus MK, Mosser DM.Rhodococcus equi is a facultative intracellular bacterium of macrophages that can cause serious pneumonia in both young horses and immunocompromised people. Essential to understanding rhodococcus pathogenesis is a quantitative documentation of the intracellular events that follow macrophage phagocytosis of the organism. By using a bacterial immunofluorescence staining assay, we verified the intracellular survival and replicative potential of R. equi in both murine peritoneal macrophages and equine alveolar macrophages in vitro. Following an initial lag period of 6 to 12 h, the intracellular nu...
Russo AT, White MA, Watowich SJ.Alphavirus replication and propagation is dependent on the protease activity of the viral nsP2 protein, which cleaves the nsP1234 polyprotein replication complex into functional components. Thus, nsP2 is an attractive target for drug discovery efforts to combat highly pathogenic alphaviruses. Unfortunately, antiviral development has been hampered by a lack of structural information for the nsP2 protease. Here, we report the crystal structure of the nsP2 protease (nsP2pro) from Venezuelan equine encephalitis alphavirus determined at 2.45 A resolution. The protease structure consists of two dist...
Tulman ER, Delhon G, Afonso CL, Lu Z, Zsak L, Sandybaev NT, Kerembekova UZ, Zaitsev VL, Kutish GF, Rock DL.Here we present the genomic sequence of horsepox virus (HSPV) isolate MNR-76, an orthopoxvirus (OPV) isolated in 1976 from diseased Mongolian horses. The 212-kbp genome contained 7.5-kbp inverted terminal repeats and lacked extensive terminal tandem repetition. HSPV contained 236 open reading frames (ORFs) with similarity to those in other OPVs, with those in the central 100-kbp region most conserved relative to other OPVs. Phylogenetic analysis of the conserved region indicated that HSPV is closely related to sequenced isolates of vaccinia virus (VACV) and rabbitpox virus, clearly grouping to...
Field H, de Jong C, Melville D, Smith C, Smith I, Broos A, Kung YH, McLaughlin A, Zeddeman A.Hendra virus is a recently emerged zoonotic agent in Australia. Since first described in 1994, the virus has spilled from its wildlife reservoir (pteropid fruit bats, or 'flying foxes') on multiple occasions causing equine and human fatalities. We undertook a three-year longitudinal study to detect virus in the urine of free-living flying foxes (a putative route of excretion) to investigate Hendra virus infection dynamics. Pooled urine samples collected off plastic sheets placed beneath roosting flying foxes were screened for Hendra virus genome by quantitative RT-PCR, using a set of primers a...
Harman RM, Yang S, He MK, Van de Walle GR.The prevalence of chronic skin wounds in humans is high, and treatment is often complicated by the presence of pathogenic bacteria. Therefore, safe and innovative treatments to reduce the bacterial load in cutaneous wounds are needed. Mesenchymal stromal cells (MSC) are known to provide paracrine signals that act on resident skin cells to promote wound healing, but their potential antibacterial activities are not well described. The present study was designed to examine the antibacterial properties of MSC from horses, as this animal model offers a readily translatable model for MSC therapies i...
Broder CC, Xu K, Nikolov DB, Zhu Z, Dimitrov DS, Middleton D, Pallister J, Geisbert TW, Bossart KN, Wang LF.Hendra virus and Nipah virus are bat-borne paramyxoviruses that are the prototypic members of the genus Henipavirus. The henipaviruses emerged in the 1990s, spilling over from their natural bat hosts and causing serious disease outbreaks in humans and livestock. Hendra virus emerged in Australia and since 1994 there have been 7 human infections with 4 case fatalities. Nipah virus first appeared in Malaysia and subsequent outbreaks have occurred in Bangladesh and India. In total, there have been an estimated 582 human cases of Nipah virus and of these, 54% were fatal. Their broad species tropis...
Walsh C, Gangloff M, Monie T, Smyth T, Wei B, McKinley TJ, Maskell D, Gay N, Bryant C.LPS signals through a membrane bound-complex of the lipid binding protein MD-2 and the receptor TLR4. In this study we identify discrete regions in both MD-2 and TLR4 that are required for signaling by lipid IVa, an LPS derivative that is an agonist in horse but an antagonist in humans. We show that changes in the electrostatic surface potential of both MD-2 and TLR4 are required in order that lipid IVa can induce signaling. In MD-2, replacing horse residues 57-66 and 82-89 with the equivalent human residues confers a level of constitutive activity on horse MD-2, suggesting that conformational...
LeBlanc MM, Causey RC.Endometritis, a major cause of mare infertility arising from failure to remove bacteria, spermatozoa and inflammatory exudate post-breeding, is often undiagnosed. Defects in genital anatomy, myometrial contractions, lymphatic drainage, mucociliary clearance, cervical function, plus vascular degeneration and inflamm-ageing underlie susceptibility to endometritis. Diagnosis is made through detecting uterine fluid, vaginitis, vaginal discharge, short inter-oestrous intervals, inflammatory uterine cytology and positive uterine culture. However, these signs may be absent in subclinical cases. Hyper...
van Dinten LC, van Tol H, Gorbalenya AE, Snijder EJ.Equine arteritis virus (EAV), the prototype Arterivirus, is a positive-stranded RNA virus that expresses its replicase in the form of two large polyproteins of 1,727 and 3,175 amino acids. The functional replicase subunits (nonstructural proteins), which drive EAV genome replication and subgenomic mRNA transcription, are generated by extensive proteolytic processing. Subgenomic mRNA transcription involves an unusual discontinuous step and generates the mRNAs for structural protein expression. Previously, the phenotype of mutant EAV030F, which carries a single replicase point mutation (Ser-2429...
Leroux C, Cadoré JL, Montelaro RC.Equine Infectious Anemia Virus (EIAV) is a lentivirus, of the Retrovirus family, with an almost worldwide distribution, infecting equids. It causes a persistent infection characterized by recurring febrile episodes associating viremia, fever, thrombocytopenia, and wasting symptoms. The disease is experimentally reproducible by inoculation of Shetland ponies or horses with EIAV pathogenic strains. Among lentiviruses, EIAV is unique in that, despite a rapid virus replication and antigenic variation, most animals progress from a chronic stage characterized by recurring peaks of viremia and fever ...
Murcia PR, Baillie GJ, Daly J, Elton D, Jervis C, Mumford JA, Newton R, Parrish CR, Hoelzer K, Dougan G, Parkhill J, Lennard N, Ormond D, Moule S....Determining the evolutionary basis of cross-species transmission and immune evasion is key to understanding the mechanisms that control the emergence of either new viruses or novel antigenic variants with pandemic potential. The hemagglutinin glycoprotein of influenza A viruses is a critical host range determinant and a major target of neutralizing antibodies. Equine influenza virus (EIV) is a significant pathogen of the horse that causes periodical outbreaks of disease even in populations with high vaccination coverage. EIV has also jumped the species barrier and emerged as a novel respirator...
Thouless ME, Bryden AS, Flewett TH, Woode GN, Bridger JC, Snodgrass DR, Herring JA.Human, piglet, mouse, foal, lamb, calf and rabbit rotaviruses all infected, but could not readily be subcultured in LLC MK2 cells. Cells infected with mouse and calf rotaviruses reacted by indirect immunofluorescence (FA) with convalescent serum from children, piglets, mice, foals, lambs, calves or rabbits, taken after rotavirus infection. Human, calf, piglet, mouse and foal rotaviruses reacted with human, calf, mouse, foal and lamb convalescent serum by complement fixation (CF). It was not possible to distinguish between different rotaviruses by CF or FA. Neutralization tests, however, detect...
Weese JS, Archambault M, Willey BM, Hearn P, Kreiswirth BN, Said-Salim B, McGeer A, Likhoshvay Y, Prescott JF, Low DE.Methicillin-resistant Staphylococcus aureus (MRSA) infection was identified in 2 horses treated at a veterinary hospital in 2000, prompting a study of colonization rates of horses and associated persons. Seventy-nine horses and 27 persons colonized or infected with MRSA were identified from October 2000 to November 2002; most isolations occurred in a 3-month period in 2002. Twenty-seven (34%) of the equine isolates were from the veterinary hospital, while 41 (51%) were from 1 thoroughbred farm in Ontario. Seventeen (63%) of 27 human isolates were from the veterinary hospital, and 8 (30%) were ...
Reperant LA, Rimmelzwaan GF, Kuiken T.Highly pathogenic avian influenza viruses of subtype H5N1 are remarkable because of their expanding non-avian host range and wide tissue tropism. They have caused severe or fatal respiratory and extra-respiratory disease in seven naturally infected species of carnivore. However, they are not unique in their ability to cross the species barrier, to cause clinical disease and mortality, or to replicate in extra-respiratory organs. Low pathogenic avian influenza viruses have crossed from birds to swine, horses, harbour seals, whales and mink; have resulted in severe respiratory disease and mortal...
Gosztonyi G, Ludwig H.Natural BD is a nonpurulent acute/subacute encephalitis of horses and sheep with a propensity to involve the olfactory and limbic systems, and the brain stem. The inflammation is concentrated primarily in the gray matter, but subcortical white matter may also be affected. Experimental BD can be produced in a series of animals from birds to primates. The neuropathology after experimental infection is similar to that in natural disease but the inflammatory changes are more diffuse. In the rat and mouse, a persistent/tolerant infection can also be induced, in which inflammatory changes are conspi...
Baptiste KE, Williams K, Willams NJ, Wattret A, Clegg PD, Dawson S, Corkill JE, O'Neill T, Hart CA.We determined the molecular characteristics of methicillin-resistant staphylococci from animals and staff at a small animal and equine hospital. Methicillin-resistant Staphylococcus aureus (MRSA) identical to human EMRSA-15 was found in dogs and hospital staff. In contrast, 5 distinct MRSA strains were isolated from horses but not from hospital staff.
Pelkonen S, Lindahl SB, Suomala P, Karhukorpi J, Vuorinen S, Koivula I, Väisänen T, Pentikäinen J, Autio T, Tuuminen T.Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is a zoonotic pathogen for persons in contact with horses. In horses, S. zooepidemicus is an opportunistic pathogen, but human infections associated with S. zooepidemicus are often severe. Within 6 months in 2011, 3 unrelated cases of severe, disseminated S. zooepidemicus infection occurred in men working with horses in eastern Finland. To clarify the pathogen's epidemiology, we describe the clinical features of the infection in 3 patients and compare the S. zooepidemicus isolates from the human cases with S. zooepidemicus isolates...
Peregrine AS, Molento MB, Kaplan RM, Nielsen MK.Parascaris equorum and cyathostomins are currently considered the most important parasites of horses and have traditionally been controlled with anthelmintics belonging to three drug classes: benzimidazoles, the tetrahydropyrimidine pyrantel, and macrocyclic lactones. Unfortunately, resistance to benzimidazoles, and to a lesser extent pyrantel, is widespread in cyathostomins around the world. Furthermore, resistance to macrocyclic lactones appears to be in the early stages of development in cyathostomins in multiple locations. In contrast, P. equorum populations have remained susceptible to th...
Niller HH, Angstwurm K, Rubbenstroth D, Schlottau K, Ebinger A, Giese S, Wunderlich S, Banas B, Forth LF, Hoffmann D, Höper D, Schwemmle M, Tappe D....In 2018-19, Borna disease virus 1 (BoDV-1), the causative agent of Borna disease in horses, sheep, and other domestic mammals, was reported in five human patients with severe to fatal encephalitis in Germany. However, information on case frequencies, clinical courses, and detailed epidemiological analyses are still lacking. We report the occurrence of BoDV-1-associated encephalitis in cases submitted to the Institute of Clinical Microbiology and Hygiene, Regensburg University Hospital, Regensburg, Germany, and provide a detailed description of newly identified cases of BoDV-1-induced encephali...
Hammond SA, Cook SJ, Lichtenstein DL, Issel CJ, Montelaro RC.Equine infectious anemia virus (EIAV) provides a natural model system by which immunological control of lentivirus infections may be studied. To date, no detailed study addressing in parallel both the humoral and cellular immune responses induced in horses upon infection by EIAV has been conducted. Therefore, we initiated the first comprehensive characterization of the cellular and humoral immune responses during clinical progression from chronic disease to inapparent stages of EIAV infection. Using new analyses of antibody avidity and antibody epitope conformation dependence that had not been...
Santín M.Cryptosporidium spp. are frequent parasites of livestock and companion animals, raising questions about the clinical significance of such infections. Cryptosporidium infections have a wide spectrum of clinical signs that can vary from asymptomatic to serious infection to death. In neonatal ruminants, cryptosporidiosis is considered an important disease characterised by diarrhoea and mortality. In companion animals most infections are asymptomatic but severe clinical illness has also been reported in dogs, cats and horses. In birds, three main clinical forms of cryptosporidiosis are primarily s...
van der Meulen KM, Pensaert MB, Nauwynck HJ.West Nile virus (WNV), an arthropod-borne virus belonging to the family Flaviviridae, had been recognized in Africa, Asia and the south of Europe for many decades. Only recently, it has been associated with an increasing number of outbreaks of encephalitis in humans and equines as well as an increasing number of infections in vertebrates of a wide variety of species. In this article, the data available on the incidence of WNV in vertebrates are reviewed. Moreover, the role of vertebrates in the transmission of WNV, the control of WNV infections in veterinary medicine as well as future perspect...
Hahn S, Giaglis S, Hoesli I, Hasler P.The intention of this review is to provide an overview of the potential role of neutrophil extracellular traps (NETs) in mammalian reproduction. Neutrophil NETs appear to be involved in various stages of the reproductive cycle, starting with fertility and possibly ending with fetal loss. The first suggestion that NETs may play a role in pregnancy-related disorders was in preeclampsia, where vast numbers were detected in the intervillous space of affected placentae. The induction of NETosis involved an auto-inflammatory component, mediated by the increased release of placental micro-debris in p...
De Cock AW, Mendoza L, Padhye AA, Ajello L, Kaufman L.Pythium insidiosum sp. nov., the etiologic agent of pythiosis, a cosmopolitan disease of horses, cattle, and dogs, is described and illustrated.
Ehlers B, Borchers K, Grund C, Frölich K, Ludwig H, Buhk HJ.A consensus primer PCR approach was used to (i) investigate the presence of herpesviruses in wild and zoo equids (zebra, wild ass, tapir) and to (ii) study the genetic relationship of the herpesvirus of pigeons (columbid herpesvirus 1) to other herpesvirus species. The PCR assay, based on degenerate primers targeting highly conserved regions of the DNA polymerase gene of herpesviruses, was modified by using a mixture of degenerate and deoxyinosine-substituted primers. The applicability of the modification was validated by amplification of published DNA polymerase genes of 16 herpesvirus specie...
Puffer BA, Watkins SC, Montelaro RC.We have identified an interaction between the equine infectious anemia virus (EIAV) late assembly domain and the cellular AP-2 clathrin-associated adapter protein complex. A YXXL motif within the EIAV Gag late assembly domain was previously characterized as a sequence critical for release of assembling virions. We now show that this YXXL sequence interacts in vitro with the AP-50 subunit of the AP-2 complex, while the functionally interchangeable late assembly domains carried by the Rous sarcoma virus p2b protein and human immunodeficiency virus type 1 p6 protein, which utilize PPPY and PTAPP ...
Nedland H, Wollman J, Sreenivasan C, Quast M, Singrey A, Fawcett L, Christopher-Hennings J, Nelson E, Kaushik RS, Wang D, Li F.Influenza D virus (IDV) is a newly described influenza type of the Orthomyxoviridae virus family that was first isolated from diseased swine in 2011 and has subsequently been detected in cattle around the world in 2014. In addition, serological evidence for IDV infection in humans has been recently established. Despite all the progress, the full range of susceptible hosts for this novel virus has yet to be determined, but includes swine, bovine, small ruminants and human. This study was designed to determine if equine is a possible host to this newly emerging influenza virus. Three hundred and...
Mahalingam S, Herrero LJ, Playford EG, Spann K, Herring B, Rolph MS, Middleton D, McCall B, Field H, Wang LF.Hendra virus, first identified in 1994 in Queensland, is an emerging zoonotic pathogen gaining importance in Australia because a growing number of infections are reported in horses and people. The virus, a member of the family Paramyxoviridae (genus Henipavirus), is transmitted to horses by pteropid bats (fruit bats or flying foxes), with human infection a result of direct contact with infected horses. Case-fatality rate is high in both horses and people, and so far, more than 60 horses and four people have died from Hendra virus infection in Australia. Human infection is characterised by an a...
Asanovich KM, Bakken JS, Madigan JE, Aguero-Rosenfeld M, Wormser GP, Dumler JS.The agent of human granulocytic ehrlichiosis (HGE), Ehrlichia phagocytophila, and Ehrlichia equi are very similar. HGE is of variable severity. Genetic and antigenic differences among 3 human isolates (Webster, Spooner, and NY-8) and 1 horse isolate (MRK) were evaluated. The 16S rRNA gene sequences were identical in all human isolates. By use of 5 homologous antisera from these 3 humans and 1 horse and an additional 5 antisera in heterologous reactions, the immunodominant antigens of each isolate were noted to differ in molecular size: 43 kDa in the Webster (Wisconsin) isolate, 46 kDa in the S...
Hardefeldt LY, Gilkerson JR, Billman-Jacobe H, Stevenson MA, Thursky K, Bailey KE, Browning GF.Antimicrobial stewardship (AMS) programs are yet to be widely implemented in veterinary practice and medical programs are unlikely to be directly applicable to veterinary settings. Objective: To gain an in-depth understanding of the factors that influence effective AMS in veterinary practices in Australia. Methods: A concurrent explanatory mixed methods design was used. The quantitative phase of the study consisted of an online questionnaire to assess veterinarians' attitudes to antimicrobial resistance (AMR) and antimicrobial use in animals, and the extent to which AMS currently is implemente...
