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.
Anderson MA, Whitlock JE, Harwood VJ.Escherichia coli is the most completely characterized prokaryotic model organism and one of the dominant indicator organisms for food and water quality testing, yet comparatively little is known about the structure of E. coli populations in their various hosts. The diversities of E. coli populations isolated from the feces of three host species (human, cow, and horse) were compared by two subtyping methods: ribotyping (using HindIII) and antibiotic resistance analysis (ARA). The sampling effort required to obtain a representative sample differed by host species, as E. coli diversity was consis...
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...
Liang CZ, Cao RB, Wei JC, Zhu LH, Chen PY.According to the antigenic analysis of equine arteritis virus (EAV) GL protein, one pair of primers were designed, with which the gene fragment coding the high antigenic domain of EAV GL protein was amplified from the EAV genome. The cloned gene was digested with BamH I and Xho I and then inserted into pET-32a and resulted pET-GL1. The pET-GL1 was transformed into the host cell BL21(DE3) and the expression was optimized including cultivation temperature and concentration of IPTG. The aim protein was highly expressed and the obtained recombinant protein manifested well reactiongenicity as was c...
Muscatello G, Gilkerson JR, Browning GF.The use of selective media to facilitate the isolation of Rhodococcus equi from environmental and clinical samples has aided studies of the ecology of R. equi and the epidemiology of disease caused by R. equi. Here, we compared the efficacy of two selective media (NANAT and modified CAZ-NB) for the recovery of six defined strains of R. equi and for the isolation and enumeration of both avirulent and virulent R. equi from 60 paired soil samples from horse farms using colony blotting and DNA hybridisation. No difference was found between the two media in the recoverability of defined strains of ...
Tu YB, Zhou T, Yuan XF, Qiu HJ, Xue F, Sun CQ, Wang L, Wu DL, Peng JM, Kong XG, Tong GZ.The long terminal repeats (LTRs) of equine infectious anemia virus donkey leukocyte-attenuated virus (EIAV-DLA) were substituted with those of the wild-type EIAV-L (wt EIAV-L, the parent virus of EIAV-DLA). The resulting chimeric plasmid was designated pOK-LTR DLA/L. Purified pOK-LTR DLA/L was transfected into monocyte-derived macrophage (MDM) cultures prepared from EIAV-negative, heparinized whole blood from a donkey. Eighth-passage cell cultures developed the typical cytopathogenic effects (CPE) of EIAV infection, and virions with typical EIAV profiles were observed with an electron microsco...
Hussey SB, Clark R, Lunn KF, Breathnach C, Soboll G, Whalley JM, Lunn DP.Equine herpesvirus-1 (EHV-1) infection is common in young horses throughout the world, resulting in respiratory disease, epidemic abortion, sporadic myelitis, or latent infections. To improve on conventional diagnostic tests for EHV-1, a real-time polymerase chain reaction (PCR) technique was developed, using primers and probes specific for the EHV-1 gB gene. Amplification efficiencies of 100% +/- 5% were obtained for DNA isolated from a plasmid, infected peripheral blood mononuclear cells (PBMCs), and nasal secretions from infected ponies. The dynamic range of the assay was 8 log10 dilutions,...
Waitt LH, Cebra CK, Tornquist SJ, Löhr CV.A 22-year-old pinto mixed breed mare was admitted for evaluation of severe colic signs and gastric reflux. Multiple nonpainful, variably sized hard masses were palpated in the subcutis over the thorax, abdomen, and hindquarters of the horse. The mare was diagnosed with sterile peritonitis and had systemically high gamma-glutamyltransferase, amylase, and lipase. Three days into treatment she became febrile with signs of persistent and mild abdominal discomfort; euthanasia was elected. Necropsy revealed peripancreatitis, pancreatic fibrosis, abdominal steatitis and panniculitis. Panniculitis ass...
Lannergård J, Guss B.Streptococcus equi ssp. equi is the causative agent of strangles, a highly contagious and serious disease in the upper respiratory tract of horses. The present study describes the characterization of IdeE, a homolog of the secreted IgG-specific protease IdeS/Mac of Streptococcus pyogenes. The activity of IdeE is compared with the activity of IdeZ, the corresponding enzyme of the closely related S. equi ssp. zooepidemicus. A study of the proteolytic activity of recombinant IdeE and IdeZ on IgG from a selection of mammals shows that only antibodies containing the substrate site of IdeS/Mac are c...
Carrieri ML, Peixoto ZM, Paciencia ML, Kotait I, Germano PM.Laboratory diagnosis is essential to confirm suspected cases of equine rabies and to determine the medical care needed for human postexposure antirabies prophylaxis. Equine rabies transmitted by the vampire bat, Desmodus rotundus, has increased gradually in the State of São Paulo. The present study has several objectives, the most important being the evaluation of fluorescent antibody test (FAT) and virus-isolation laboratory tests performed with different equine nervous system tissues (cortical, hippocampus, cerebellar, brainstem and cervical medullar) to determine the tissue for which the t...
Goodwin D, Gennari SM, Howe DK, Dubey JP, Zajac AM, Lindsay DS.Encephalitozoon cuniculi has been associated with natural cases of abortion and stillbirth in horses. However, little is known about the prevalence of this parasite in horses. We examined sera from 559 horses from Brazil for antibodies to E. cuniculi using the indirect immunofluorescent antibody (IFA) test and the direct agglutination test (DAT). We found that 79 (14.1%) were positive in the IFA test and 70 (12.5%) were positive in the DAT. Compared to the IFA as the "gold standard" the sensitivity of the DAG was 94.0% and the specificity was 96.1%. Our study indicates that horses in Brazil ar...
Eysker M, van Doorn DC, Lems SN, Weteling A, Ploeger HW.Due to excessive and inappropriate use of dewormers anthelmintic resistance has developed as a significant problem in horse parasites in the Netherlands. Since it is unlikely that new classes of anthelmintics against horse nematodes will be introduced in the near future, it is important to use the present drugs wisely. Veterinarians should advice horse owners about worm control programs with a more targeted approach. The number of anthelmintic treatments should be reduced and, through selective anthelmintic treatments, further development of anthelmintic resistance should be delayed. Preferabl...
Schaaf KL, Kannegieter NJ, Lovell DK.A Warmblood horse presented with a purulent nasal discharge that had failed to respond to antibiotic therapy. Radiography and endoscopy confirmed a large number of chondroid masses (over 200) in the left guttural pouch. Despite the large number of chondroids present, there was no external swelling evident. The masses were surgically removed via a hyovertebrotomy approach that provided excellent exposure, and no postoperative complications were encountered. Long term follow-up (3 years) confirmed a successful outcome.
Pei Y, Dupont C, Sydor T, Haas A, Prescott JF.To analyze further the role in virulence of the prominent cholesterol oxidase (ChoE) of Rhodococcus equi, an allelic exchange choE mutant from strain 103+ was constructed and assessed for virulence in macrophages, in mice, and in foals. There was no difference between the mutant and parent strain in cytotoxic activity for macrophages or in intra-macrophage multiplication. No evidence of attenuation was obtained in macrophages and in mice, but there was slight attenuation apparent in four intra-bronchially infected foals compared to infection of four foals with the virulent parent strain, based...
Traub-Dargatz JL, Weese JS, Rousseau JD, Dunowska M, Morley PS, Dargatz DA.Reduction factors (RFs) for bacterial counts on examiners' hands were compared when performing a standardized equine physical examination, followed by the use of one of 3 hand-hygiene protocols (washing with soap, ethanol gel application, and chlorohexidine-ethanol application). The mean RFs were 1.29 log10 and 1.44 log10 at 2 study sites for the alcohol-gel (62% ethyl alcohol active ingredient) protocols and 1.47 log10 and 1.94 log10 at 2 study sites for the chlorhexidine-alcohol (61% ethyl alcohol plus 1% chlorhexidine active ingredients) protocols, respectively. The RFs were significantly d...
Borchers K, Ebert M, Fetsch A, Hammond T, Sterner-Kock A.Equine herpes virus 2 (EHV-2), a gamma(2)-herpesvirus, is common in horses of all ages. Its role as a primary pathogen is unclear but there is an association between EHV-2, respiratory disease and keratoconjunctivitis. The purpose of this study was to gain more information on the prevalence of EHV-2 DNA in conjunctival swabs from horses with and without ocular disease and to define the anatomical site and cell type harbouring viral genome or antigen. By polymerase chain reaction (PCR) 22 out of 77 (28.6%) ocular swabs of clinically healthy and only 4 out of 48 (8.3%) samples from diseased hors...
Kydd JH, Davis-Poynter NJ, Birch J, Hannant D, Minke J, Audonnet JC, Antczak DF, Ellis SA.Equine herpesvirus 1 (EHV-1) causes respiratory and neurological disease and abortion in horses. Animals with high frequencies of cytotoxic T lymphocytes (CTL) show reduced severity of respiratory disease and frequency of abortion, probably by CTL-mediated control of cell-associated viraemia. This study aimed to identify CTL epitopes restricted by selected major histocompatibility complex (MHC) class I alleles expressed in the equine leukocyte antigen (ELA) A3 haplotype. Effector CTL were induced from EHV-1-primed ponies and thoroughbreds with characterized MHC class I haplotypes and screened ...
Chahan B, Zhang S, Seo JY, Nakamura C, Zhang G, Bannai H, Jian Z, Inokuma H, Tuchiya K, Sato Y, Kabeya H, Maruyama S, Mikami T, Xuan X.The prevalence of Babesia (Theileria) equi and B. caballi infections in donkeys in western Xinjiang China was investigated. In total, 93 serum samples were randomly taken from donkeys in the Kashi and Ili areas, and examined for B. equi and B. caballi infections by enzyme-linked immunosorbent assays using recombinant antigens. Of the 93 samples, 9 (9.6%) and 36 (38.7%) samples were positive for B. equi infection and B. caballi infection, respectively. In addition, 2 (2.2%) samples were positive for both B. equi and B. caballi infections. These results indicate that equine babesiosis might be e...
Gawor J.The study was performed to evaluate intensity of strongylid infection in stabled tarpans using the method of collecting worms after anthelmintic treatment and in wild tarpans from Popielne reserve on the basis of faecal examination. After treatment with ivermectin 12 cyathostomes and one large strongyle species were recovered from the faeces of two tarpans. The most abundant cyathostome species were C. catinatum, C. pateratum, C. longibursatum, C. nassatum and C. coronatus. A higher intensity of infections with small strongyles (cyathostomes) was found in stabled group than in the group from t...
Romaniuk K.The Diptera attacked domestic animals in Poland are: Simuliidae, Culicidae, Tabanidae, Gasterophilidae, Hypoder-matidae and Muscidae. The insect assail the crazing animals, mostly during sunny day dna at close of day. Lack of effective repelents and also difficulties with their usage, makes it impossible to complete extermination of parasitic insects in the environment. It is posible to effectively fight against Hypoderma bovis and Gasterophilus spp.
The Journal of parasitologyAugust 4, 2006
Volume 92, Issue 3 637-643 doi: 10.1645/0022-3395(2006)92[637:PAOPRC]2.0.CO;2
Furr M, McKenzie H, Saville WJ, Dubey JP, Reed SM, Davis W.The ability of ponazuril to prevent or limit clinical signs of equine protozoal myeloencephalitis (EPM) after infection with Sarcocystis neurona was evaluated. Eighteen horses were assigned to 1 of 3 groups: no treatment, 2.5 mg/kg ponazuril, or 5.0 mg/kg ponazuril. Horses were administered ponazuril, once per day, beginning 7 days before infection (study day 0) and continuing for 28 days postinfection. On day 0, horses were stressed by transport and challenged with 1 million S. neurona sporocysts per horse. Sequential neurologic examinations were performed, and serum and cerebrospinal fluid w...
Jesty SA, Reef VB.This article first reviews cardiovascular infections, including endocarditis, myocarditis, vasculitis, and pericarditis. It then addresses what is known at this stage about the effects of sepsis on the cardiovascular system. Some information is provided from current human literature to familiarize the reader with the diagnostics and therapeutics that may eventually be used in equine practice as well.
Santschi EM.The best defense against postoperative infection is to use multiple strategies to minimize wound contamination, maintain wound tissue health, and provide rational antimicrobial strategies that do not promote the development of resistant bacteria and superinfections.
Brown VA, Wilkins PA.Techniques for novel approaches to the diagnosis and management of equine pulmonary disease continue to be developed and used in clinical practice. Diagnostic techniques involving immunoassays and nucleic acid-based tests not only decrease the time in which results become available but increase the sensitivity and specificity of test results. These assays do not substitute for careful clinical evaluation but can shorten the time to a confirmed accurate diagnosis, and thus allow for early initiation of therapeutic strategies and prevention protocols. With further understanding of the molecular ...
Frye MA.Equine urinary tract infection (UTI) most commonly occurs as a sequela to structural or functional inhibition of normal urine flow. Although it is an infrequent diagnosis in equids, the incidence of UTI in human beings is high and has inspired great investigative effort. The resultant findings with potentially broad application as well as current equine studies are reviewed here. Recent developments in the understanding of host-agent interactions and renal defense mechanisms, emerging antimicrobial resistance, and novel therapeutic alternatives to prophylactic antibiotic use are emphasized.
Feary DJ, Hassel DM.Enteritis and colitis remain challenging and life-threatening diseases despite many recent advances. Successful treatment is largely dependent on early recognition and directed therapy, which is facilitated by obtaining a complete history and physical examination. A number of new therapies and methods of monitoring critically ill patients have become integral components of treatment success. The critical monitoring of equine foals and adults continues to be an exciting and emerging field.
Lu KG, Morresey PR.Diagnosis, treatment, and, ultimately, prevention of reproductive disease are vital components of equine veterinary medicine. A thorough understanding of anatomy and physiology is necessary to reconcile the pathologic findings of disease. Only then can a rational treatment plan be formulated. Many recent advances in knowledge about the reproductive system of multiple species have application to the mare and stallion.
Southwood LL.Although the use of antimicrobials has had an insurmountable impact on preventing patient morbidity and mortality, problems with antimicrobial resistance and antimicrobial-induced diarrhea are becoming more apparent in human and veterinary medicine. The mortality associated with nosocomial infection with antimicrobial-resistant bacteria in human patients is alarming. Similarly, in veterinary medicine, the morbidity and high cost of treatment of patients with postoperative infection, for example, are concerns. Specifically in equine medicine, the high morbidity and mortality associated with ant...
Adam EN, Southwood LL.Surgical site infections (SSIs) and traumatic wound management remain challenging clinical scenarios. The prevention of SSIs involves meticulous surgical technique and aftercare. Traumatic wounds require thorough evaluation to assess the involvement of synovial structures and radiographs to check for fractures. Chronic wounds can require a biopsy and histologic evaluation to obtain a diagnosis, because many underlying pathologic processes grossly appear similar but different treatment regimens are required. Early recognition and diagnosis of cellulitis and myositis enable the rapid aggressive ...
Khosravi M, Kavosh F, Taghavi-Moghadam A, Ghaem-Maghami S, Pirali-Kheirabadi K, Rahimi-Feyli P, Navid-Pour S, Amin-Pour A, Arbabi F.No abstract available
Freestone JF, Hietala S, Moulton J, Vivrette S.A 7-year-old horse with no previous history of illness was determined to have a systemic infection of Rhodococcus equi. Rhodococcus equi was isolated from blood, tracheal fluid, and feces. Lymphopenia, failure to respond to concanavalin A and phytohemagglutinin lymphocyte stimulation testing, decreased concentrations of immunoglobulin (Ig)M, IgA, and IgG, low R equi antibody titer, histologic depletion of lymphoid tissue, and a failure to respond to antigenic stimulation led to the conclusion that both humoral and cell-mediated immunity were compromised. No cause for the acquired immunodeficie...
Freeland RB, Morello SL, DeLombaert M, Rajamanickam V.To quantify the influence of intravenous regional limb perfusion (IVRLP) with amikacin on bacterial bioburden in limb wounds. Methods: In vivo, experimental. Methods: Four adult horses. Methods: Full thickness wounds created on each dorsal metacarpus were inoculated with Staphylococcus aureus. One forelimb was randomly assigned to cephalic vein IVRLP with amikacin on days 2, 3, and 4 post-wounding. Biopsies on day 2 prior to IVRLP, and on days 5 and 8 were cultured to quantify wound bioburden (CFU/g). Two horses repeated the study in a crossover design, receiving IVRLP on the opposite limb (nâ...
Lawson GH, McPherson EA, Murphy JR, Nicholson JM, Wooding P, Breeze RG, Pirie HM.The sera of horses affected and not affected with chronic obstructive pulmonary disease (COPD) were examined for precipitins to Micropolyspora faeni and Aspergillus fumigatus. Precipitins to both antigens were not restricted to COPD cases but occurred more frequently in animals affected with COPD. Many animals without detectable precipitins responded clinically to inhalation challenge with these antigens.
Racine J, Vidondo B, Ramseyer A, Koch C.To describe a closed castration technique in standing equids, report associated complications, and identify potential risk factors. Methods: Prospective cohort study of 300 standing equids that were castrated with the Henderson Equine Castrating Instrument. Methods: Thirteen participating veterinarians recorded intraoperative difficulties and postoperative complications. Descriptive statistics, univariate analyses with Fisher's exact tests, and logistic regressions were used to evaluate intraoperative difficulties and postoperative complications and to assess risk factors for postoperative com...
Sanchez B, Nieto A, de Ruiz Leon MA, RodrÃguez J, Flores J.A lymphangiosarcoma with metastases was found in a horse that presented with respiratory distress and edema in the ventral thorax and abdomen. The necropsy revealed diffuse edema in the subcutaneous connective tissue. Mediastinal, mesenteric, iliac, and renal lymph nodes were enlarged and white with soft, yellowish necrotic areas. Histologic examination revealed numerous channels and disorganized vessels lined by large polyhedral, polymorphic cells. Tumor metastases were observed in the spleen, lungs, and kidneys. Immunohistochemical evaluation of the tumor cells demonstrated positive staining...