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.
HARDY FM, ARBITER D.Hardy, Frank M. (Fort Detrick, Frederick, Md.), and David Arbiter. Lipid inclusions in L cells associated with Venezuelan equine encephalomyelitis virus infection. J. Bacteriol. 89:1101-1103. 1965.-Venezuelan equine encephalomyelitis (VEE) virus has been shown to induce changes of lipid components within the L cell. Lipid inclusions in the form of dark granular bodies were observed in the L cell after aqueous osmium tetroxide fixation and Sudan black staining. Microscopic examination of cells as early as 8 hr after infection with VEE virus showed an increase in the concentration of these inclu...
McManamny LF.This research argues for the veterinarians leading the planning and enforcement of disease control measures in thoroughbred stud farms, emphasizing their expertise and knowledge in disease diagnosis and management. Collaboration […]
Hannant D.This study investigates severe equine asthma (sEA), a significant health risk in horses similar to human asthma, identifying latex found in riding arenas and racetracks as a potential risk factor. […]
Glatthaar R.In April 1996 an attack of black flies (Diptera, Simuliidae) to horses was observed in the region of Basle, Switzerland. Females of Simulium erythrocephalum and Simulium ornatum were involved in this attack, part of them had taken a blood meal. For S. ornatum this is the first record in Switzerland that this species takes blood meals on horses.
Hosseinzadeh S, Nofouzi K, Hasanzadeh F, Esmaeili S, Ayen E.Q fever is a frequently occurring illness that is induced by the bacterium ) that can infect humans and various animals. It targets the macrophage cells in the tissues, and circulating monocytes. Unassigned: This study was conducted between 2022 and 2023 in the West Azerbaijan and Ardabil provinces of northwestern Iran to examine the presence infection of . Specimens were obtained by swabbing from 140 mares (70 from each province) and 20 stallions (10 from each province) which were apparently healthy, and their DNA was analyzed using quantitative PCR assay detecting the element of the bacteri...
MacNeill AL, Micheloud JF, Parvin R, Gjessing M, Airas NA, Sant'Ana FJF, Adamek M.Zoonotic poxviruses, including monkeypox virus (MPV), the causative agent for Mpox disease, have gained significant media and scientific attention due to recent outbreaks in human populations across the globe. The increase in human cases of poxvirus infection is not unexpected, as routine vaccination against smallpox (a disease caused by the poxvirus variola virus, which cross protects against other orthopoxviruses) was discontinued in the 1980s after its eradication. Large numbers of vertebrate and invertebrate species are susceptible to infection by . Clinical signs and histologic lesions ca...
Slavik K, Whitlock R, Johnson A.Botulism is a severe and often fatal disease in equine patients worldwide. Clostridium botulinum is a ubiquitous soil organism which produces a potent neurotoxin resulting in neuromuscular blockade and flaccid paralysis in affected animals. Definitive diagnosis is often impractical or impossible, leading to diagnosis and treatment based on clinical experience and presenting signs. Delay in case identification and treatment results in rapid deterioration of the patient. Treatment of recumbent equine botulism cases presents challenges due to patient size and requires intensive nursing care. This...
Whitlock F, McGlennon A, Newton R, Riley K.As part of her undergraduate research project, Cambridge vet student Katie Riley surveyed the attitudes of UK veterinarians with regard to preventing and controlling strangles, including the use of vaccination. Here, she and Fleur Whitlock, Abigail McGlennon and Richard Newton of Equine Infectious Disease Surveillance discuss her findings.
Rakaki ME, van der Walt M, Williams J, Venter M.We detected Shuni virus in horses and ovine fetuses and Shamonda virus in a caprine fetus in South Africa. We identified a Shuni/Shamonda virus reassortant in a horse and Shuni/Caimito, Shamonda/Caimito, and Shamonda/Sango virus reassortants in Culicoides midges. Continued genomic surveillance will be needed to detect orthobunyavirus infections in Africa.
Drury M.Participants in the 1- and 2-day Tamworth Dressage Club (TDC) annual dressage championships arrived in Moonbi, New South Wales (NSW) as reports of the equine influenza outbreak surfaced on 25 August 2007. Three horses who had attended a competition in Maitland the weekend before had been showing flu-like symptoms and the next day the site was declared a suspect premise. On 27 August, infection was confirmed and the site was placed in total quarantine. Although most participants had travelled long distances to compete and did not have provisions for them or their horses, the quarantine was not ...
Kukurić T, Erdeljan M, Matthews JB, Lightbody KL, Austin CJ, Peczak N, Uzelac A, Klun I, Simin S. 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 ...
Dersch K, Kreuder A, Wang C, Troy J.Surgical site infections (SSI) are a common postoperative complication of equine orthopedic surgery and often increase morbidity and mortality. Objective: This study aimed to determine if covering surgical instruments during surgery decreased bacterial environmental air contamination during early opening of surgical packs (EOSP). The authors hypothesized that covering instruments with sterile surgical towels would reduce the total number of bacterial colonies to which the instruments were exposed. Methods: Blood agar plates (BAP) were allocated into two groups (non-covered vs. covered with a s...
Magdesian KG.Knowledge of immunodeficiencies is crucial to neonatal medicine, in that they predispose to sepsis in the newborn and neonatal foal, as well as recurrent infections in older foals. The most common immunodeficiency in newborn and neonatal foals is failure of passive transfer, which is an example of an acquired immunodeficiency. Congenital or developmental immunodeficiencies may be transient or permanent, and can either affect the cell-mediated or humoral arms of immunity, and in some cases both. Affected foals often have chronic or recurrent respiratory or gastrointestinal infections, often wit...
Nara PL, Krakowka S, Powers TE, Garg RC.Fourteen young outbred horses, divided into 2 groups on the basis of 18- or 24-hour skin-test reactions to Streptococcus equi, were inoculated nasopharyngeally with virulent S equi. Animals (n = 6, group I) with evidence of previous exposure to S equi (positive dermal response and existing serum antibodies), with one exception, developed minimal or no signs of disease after inoculation. In contrast, S equi skin-test negative and seronegative horses (n = 8, group II) developed predictable and severe clinical signs of infection after their inoculation, including shedding of the organism from nas...
Monzón CM.A direct agglutination test is described to diagnose 'Mal de Caderas' caused by Trypanosoma evansi. The antigen used was a suspension of trypsin-treated parasites stabilized with formalin. The test was evaluated in horses with both natural and experimental infections. Test sensitivity and specificity were 94 and 97%, respectively. Treatment of serum with 2-mercaptoethanol before testing permitted the differentiation of IgM and IgG antibodies, and possible differentiation of current infection from past exposure to the parasite. The antigen was stable over a 6-month evaluation period and also sh...
Peter V, Marr C, Foote A, Auer H, Head M.This case report describes a 13-year-old cob-cross gelding presented for evaluation of recent onset hindlimb ataxia. The gelding had undergone general anaesthesia and tenoscopy of the right hindlimb digital flexor tendon sheath at a nearby clinic three months earlier and had appeared normal at routine post-operative assessments until the sudden onset of neurological deficits. Spinal trauma was suspected initially but radiography and scintigraphy were unremarkable. Due to the severity and progressive nature of the clinical signs the -gelding was subjected to euthanasia. Post mortem examinations...
Thein P, Brown K.Infections with EHV1 can lead to manifestation at the CNS of horses followed by encephalomyelitis and "equine stroke". Horse experiments could confirm the clinical picture and gave links to the potential pathogenesis of the disease. We also have been in the position to isolate and characterize an EHV4 virus out of the brain of a horse with CNS disorders. The two viruses carry different biological properties which obviously dominate the pathogenesis. These properties as well as experimental and field cases are described and different diagnostic tests are discussed.
Atwill ER, Mohammed HO, Lopez JW.To determine whether mean annual frequency and destination of equine travel was associated with exposure to Ehrlichia risticii and whether these associations were modified by horses' place of residence. Methods: Cross-sectional study. Methods: 511 equine operations containing 2,587 horses were visited in New York state from a target population of 39,000 operations. Methods: Each horse was tested for serum antibodies against E risticii, using indirect fluorescent antibody. Information on the horse's travel history, farm's management practices, and surrounding ecology was obtained by personal in...
Cohen ND, Kahn SK, Cywes-Bentley C, Ramirez-Cortez S, Schuckert AE, Vinacur M, Bordin AI, Pier GB.Rhodococcus equi is a prevalent cause of pneumonia in foals worldwide. Our laboratory has demonstrated that vaccination against the surface polysaccharide β-1→6-poly-N-acetylglucosamine (PNAG) protects foals against intrabronchial infection with R. equi when challenged at age 28 days. However, it is important that the efficacy of this vaccine be evaluated in foals when they are infected at an earlier age, because foals are naturally exposed to virulent R. equi in their environment from birth and because susceptibility is inversely related to age in foals. Using a randomized, blind experim...
Molini U, Franzo G, Rautenbach I, Otto HV, Khaiseb S, Di Gennaro A, Ntahonshikira C, Baines I, Monaco F, Savini G, D'Alterio N.West Nile virus (WNV) is a vector-borne virus maintained in nature by a bird-mosquito cycle. However, it can occasionally and accidentally infect horses and human beings, leading to sometimes severe or even fatal outcomes in these species. Therefore, the monitoring of its circulation and disease occurrence is of relevance. Unfortunately, it is underdiagnosed or not diagnosed in several African counties, including Namibia, where no data is currently available for horses. In this study, 98 horses in three different stables in the Windhoek city area were investigated. They were found to have a se...
Hochart É, Fournier Y.Equestrian sports are widely practiced in Switzerland as hobbies. Horses are imposing and unpredictable. As a result, traumatisms associated with horseback riding are common and cause serious injuries. Cranial traumatisms are among the most frequently encountered injuries and are associated with high rates of hospitalization and mortality. Helmet use decreases the severity of intracranial lesions. Close contact with horses can lead to the development of infectious diseases and respiratory allergies. Although infrequent in Europe, these infections occur sporadically and should be known by gener...
Morse EV, Duncan MA, Fessler JF, Page EH.Among 23 Equidae in which various treatment or management regimens for salmonellosis were observed and evaluated, 9 horses were infected with Salmonella typhimurium and 8 with S anatum; an aged mule harbored S newport, and 1 isolant was not identified. Four dual sero-type infections occurred: 3 typhimurium/anatum and 1 anatum/newington. The results obtained with various antimicrobials in therapy of peracute, acute, and chronic infections were discouraging or questionable with regard to efficacy against salmonellae per se. The antimicrobial resistance patterns of the salmonellae and coliforms f...
Denyer MS, Crowther JR.Antigenic differences within equine-1 and equine-2 isolates of influenza were studied by haemagglutination inhibition tests, indirect ELISA and competition ELISA, using the same antisera. Better differentiation was obtained with the competition ELISA than with the other two tests. All three methods produced similar relationships within the equine-1 isolates but differed in their ability to differentiate the equine-2 isolates where the competition ELISA was superior and produced epidemiologically sensible results. In all three tests, post-infection ferret and horse sera were more useful in disc...
Equine lentivirus receptor-1 (ELR1) has been characterized as the specific functional receptor that mediates equine infectious anemia virus (EIAV) entrance to horse macrophages. This receptor is tumor necrosis factor receptor superfamily member 14 (TNFRSF14). The aim of this study was to investigate the occurrence of allelic variants in the coding sequence of equine TNFRSF14 gene by screening for single-nucleotide polymorphisms (SNPs) in different equine populations. Forty seven horse samples were randomly selected from a reservoir of EIAV-seropositive and seronegative samples collected from d...
Khan A, Mushtaq MH, Ahmad MUD, Nazir J, Fatima Z, Khan A, Farooqi SH.EI in non-vaccinated population causes disruption and economic losses. To identify the risk factors associated with the EI epidemics in equids in Pakistan, a 1:1 matched case control study was conducted during 2015-2016. Including a total of 197 laboratory confirmed cases and negative controls, matched on the basis of geography, time of sampling, specie and age. A piloted questionnaire was used to collect data regarding risk factors associated with the occurrence of EI in face to face interviews. Conditional logistic regression was performed to analyze the data. A total of 16 out of 23 variabl...
Liu L, Castillo-Olivares J, Davis-Poynter NJ, Baule C, Xia H, Belák S.Samples from horses experimentally infected with the "large plaque variant (LP3A+)" of equine arteritis virus were analysed. These included 182 nasal swabs collected from day 1 to 14 post-infection (p.i.), and 21 virus isolates obtained from white blood cells of animals that showed a prolonged viraemia between days 30 to 72 p.i. In order to determine the genetic stability of the virus and particularly to characterise the genetic variants found during the prolonged viraemia, partial sequences of open reading frame 5 (ORF5) encoding glycoprotein 5 (GP5) were generated. Viruses with amino acid su...
Furniss C, Carstens A, Cilliers I.A 12-year-old, grey, crossbred pony mare was presented with a swelling in the neck over the area of the 2nd cervical vertebra (C2), which was found to be painful on palpation. The neck was held stiffly. Radiography of the cervical region showed a focal area of increased radio-opacity over the dorsal, caudal and lateral aspect of the dorsal spinous process of C2. Ultrasound confirmed the presence of a hypoechoic area approximately 15 cm in diameter superimposed over the dorsal spinous process of C2. An aspirate was taken of the mass, which revealed purulent exudate confirming the diagnosis of a...
Ruppert S, Lee JK, Marsh AE.A 6-year-old female captive zebra (Equus zebra) had a three-year history of slow progressive neurologic signs that recently worsened with hind limb ataxia, head tilt, and circling. Gross examination including the brain and spinal cord were unremarkable. On histopathology, the brain and brainstem had multiple random areas of severe lymphoplasmacytic meningoencephalitis associated with numerous 15-25 μm in diameter protozoal cysts with a discernible outer wall containing numerous 2 × 4 μm oval to crescent-shaped organisms. Immunohistochemistry and PCR identified the presence of Neospora or...
McBeath DG, Wells PW, Eyre P, Hanna CJ.This paper attempts to relate the practicalities of vaccine development to the ideals which should be aimed for in a new vaccine. The type of immune response induced is dependent upon the nature of the antigen in the vaccine and the site and timing of its presentation to the immune system. In this respect the influence of age, maternal immunity and antigenic competition are discussed. The possible side effects associated with vaccination are defined and vaccines which are currently available for horses are reviewed. These vaccines are mostly for the prevention of respiratory disease. Finally, ...
