Topic:Leptospira
Leptospira is a genus of spirochete bacteria that can infect horses, leading to a range of health issues. These bacteria are responsible for leptospirosis, a zoonotic disease that can affect multiple animal species, including humans. In horses, leptospirosis can result in conditions such as uveitis, abortion, and renal disease. The transmission of Leptospira occurs through direct or indirect contact with contaminated water, soil, or the urine of infected animals. Diagnosis of leptospirosis in horses involves serological testing and detection of the bacteria in bodily fluids. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, pathogenesis, diagnosis, and management of leptospirosis in equine populations.
Subclinical leptospirosis may impair athletic performance in racing horses. The infection by Leptospira in horses, in both its acute disease and subclinical forms, is very common, particularly in endemic regions. Therefore, the objective of this study was to evaluate the effects of subclinical leptospirosis in the athletic performance of racing thoroughbred horses. Athletic performance of 119 racing Thoroughbred horses from Rio de Janeiro, Brazil, was calculated by assigning a point value for the results in racing (performance index (PI)), and serology for leptospirosis was conducted. A total of 85 (71.4 %) horses showed reactive titers (≥ 100), and of which 52 had ...
The role of horses in the transmission of leptospirosis in an urban tropical area. The objective of this study was to demonstrate the presence of leptospires in equine urine, as evidence for a potential role of horses in transmission of this organism. Thoroughbred horses (aged 2-5 years, n = 276) from Rio de Janeiro, Brazil, were studied. After a severe storm, the premises of the animals remained flooded for 72 h. Blood samples for serology were collected on days 20 and 35 (day of storm = day 0). On day 20, 132 (47·8%) horses were seroreactive (titre ≥200) and, of these, 23 (31·0%) had increased antibody titres on day 35. Furthermore, 34 urine samples (for PCR and cultur...
Antibodies to a novel leptospiral protein, LruC, in the eye fluids and sera of horses with Leptospira-associated uveitis. Screening of an expression library of Leptospira interrogans with eye fluids from uveitic horses resulted in identification of a novel protein, LruC. LruC is located in the inner leaflet of the leptospiral outer membrane, and an lruC gene was detected in all tested pathogenic L. interrogans strains. LruC-specific antibody levels were significantly higher in eye fluids and sera of uveitic horses than healthy horses. These findings suggest that LruC may play a role in equine leptospiral uveitis.
Seroprevalence of Leptospira spp. in clinically healthy horses in Switzerland. A retrospective, cross-sectional study was conducted to determine the leptospiral seroprevalence in clinically healthy horses in Switzerland. A representative sample of 615 horse sera was examined by microscopic agglutination test for the presence of antibodies against 15 Leptospira spp. serovars. In total, 58.5 % (n = 360) of the horses were positive for one or more of the antigens analysed, with 20.3 % of them showing titres >= 400. The most prevalent serovar was Pyrogenes (22.6 %), followed by serovars Canicola (22.1 %) and Australis (19.2 %). Older horses, mares, ponies and ani...
Equine recurrent uveitis: classification, etiology, and pathogenesis. Equine recurrent uveitis is a cyclical disease that affects the eye and often leads to high management costs and unfavorable results, such as blindness. Research has improved understanding of the roles of various etiologies, especially leptospirosis, in initiating and perpetuating the pathogenesis of equine recurrent uveitis. Research has also led to the discovery that specific breeds and horses with specific coat color patterns may be predisposed to developing recurrent uveitis.
Exposure of free-ranging wild carnivores, horses and domestic dogs to Leptospira spp in the northern Pantanal, Brazil. Leptospirosis is a zoonotic disease affecting most mammals and is distributed throughout the world. Several species of domestic and wild animals may act as reservoirs for this disease. The purpose of this study was to assess the exposure of free-ranging wild carnivores, horses and domestic dogs on a private reserve located in the northern Pantanal (Brazil) and the surrounding areas to Leptospira spp from 2002-2006, 75 free-ranging wild carnivores were captured in the Pantanal and serum samples were collected. In addition, samples from 103 domestic dogs and 23 horses in the region were collecte...
Serum platelet-activating factor acetylhydrolase and paraoxonase-1 activity in horses infected with Leptospira spp. The aim of the study was to investigate the effect of infection with Leptospira spp. in horses on activities of platelet-activating factor acetylhydrolase (PAF-AH) and paraoxonase-1 (PON1) considering the anti-inflammatory/anti-oxidative properties of both enzymes. A total of 63 sport and leisure horses' sera were chosen among those routinely serologically examined on leptospirosis during the year 2009 in Croatia. Sera were divided into three groups according to the estimated level of antibody titre against Leptospira spp; group 1: sera serologically negative to leptospirosis (antibody titre<5...
A unique genotype of Leptospira interrogans serovar Pomona type kennewicki is associated with equine abortion. Although serologic data indicate horses in N. America are exposed to a variety of leptospiral serovars, abortion is almost always associated with Leptospira interrogans serovar Pomona type kennewicki. A variety of wildlife including raccoons, white tailed deer, striped skunks, opossums, and red and grey foxes have been shown to host serovar Pomona and have therefore been suspect as sources of infection for pregnant mares. The aim of the present study was to examine genetic diversity in serovar Pomona type kennewicki in wildlife and in aborting mares. Our approach utilized PCR that targeted tan...
Equine recurrent uveitis: the European viewpoint. Equine recurrent uveitis (ERU) has always been and still is an important disease with a significant impact on the horse industry in Europe, with a prevalence of 8-10%. The need to understand and manage the disease has spurred the development of veterinary ophthalmology in general, although the aetiology of the disease remains the subject of intense discussion. It is most probably an autoimmune disease triggered, at least in Europe, in the majority of cases by Leptospira spp. The therapy of ERU has evolved over the centuries from various methods of bloodletting to rational medical therapy using...
Equine uveitis: a UK perspective. Uveitis in the equine population of the UK does not appear to be as prevalent or disastrous as seen across regions of Europe and the USA. Some cases perceived to be recurrent uveitis may be poorly resolved single episodes of uveitis and care should be taken not to make the diagnosis of recurrence without ensuring effective control of the initial episode. Leptospira spp. appear to play only a minor role ERU in the UK which is probably the main reason for the prevalence of the disease being much lower compared to the USA and mainland Europe. Actual data are relatively few on the ground as far as...
Experimental Leptospira interrogans serovar Kennewicki infection of horses. Little information is available about experimental induction of leptospirosis in horses. Objective: Determine serologic, hematologic responses of horses to Leptospira interrogans serovar Kennewicki infection. Methods: Four adult horses seronegative for leptospirosis. Methods: Experimental and observational study. Horses were challenged with an equine isolate of L. interrogans serovar Kennewicki at 2 different doses and different inoculation sites. After challenge, the horses were monitored for 60 days. Blood, urine, and aqueous humor samples were collected at intervals until euthanasia 60 days...
Seroprevalence of Leptospira spp. in clinically healthy racing horses in Korea. Leptospirosis is a zoonotic disease of global importance, and has a worldwide distribution. The present study aimed to determine leptospiral seroprevalence in clinically healthy racing horses from all three racecourses in Korea. Serum samples from 1,226 racing horses were examined using a microscopic agglutination test to detect the presence of antibodies against 18 Leptospira serovars. Of the tested samples, 307 (25.0%) were found to be positive. The distribution of seroprevalence differed significantly by racecourse (P=0.004); the Jeju course had the highest incidence (31.1%), followed by th...
Leptospira seroprevalence and associations between seropositivity, clinical disease and host factors in horses. A cross-sectional study was carried out to determine the seroprevalence of different serovars of Leptospira spp. and their association with clinical disease and host factors in Swedish horses. Methods: Sera from 2017 horses brought to equine clinics during 1997-98 were investigated. The sera were examined by microscopic agglutination test for the presence of antibodies against the following L. interrogans serovars: Bratislava strain Jez, Icterohaemorrhagiae strain Kantorowicz and Pomona strain Pomona and also L. kirschneri sv Grippotyphosa strain Duyster and L. borgpetersenii sv Sejroe strain ...
Role of bacteria in the pathogenesis of recurrent uveitis in horses from the southeastern United States. To determine the role of intraocular bacteria in the pathogenesis of equine recurrent uveitis (ERU) in horses from the southeastern United States by evaluating affected eyes of horses with ERU for bacterial DNA and intraocular production of antibodies against Leptospira spp. Methods: Aqueous humor, vitreous humor, and serum samples of 24 clinically normal horses, 52 horses with ERU, and 17 horses with ocular inflammation not associated with ERU (ie, non-ERU inflammation). Methods: Ribosomal RNA quantitative PCR (real-time PCR) assay was used to detect bacterial DNA in aqueous humor and vitreou...
Ocular penetration of intravenously administered enrofloxacin in the horse. Information on antibiotic concentrations in the equine eye following systemic therapy is limited. Reports that Leptospira spp. are frequently present in the eyes of horses with recurrent uveitis, emphasises a need for studies on ocular concentrations of specific antibiotics. Objective: 1) Enrofloxacin, administered i.v. at 7.5 mg/kg bwt q. 24 h, results in aqueous humour concentrations greater than the reported minimum inhibitory concentration (MIC) for Leptospira pomona. 2) Aqueous humour paracentesis sufficiently disrupts the blood-aqueous humour barrier (BAB) to cause an increase in aqueous...
Occurrence of antibodies against Leptospira spp. in horses of the urban area of Londrina, Paraná, Brazil. A total of 320 horses were studied in this paper, both male and female, between two and 17 years of age, which were used for traction of wagons in the urban area of the municipality of Londrina (PR). These animals were kept, after their daily work, in abandoned areas or plots, in the outskirts of the urban area of the city. When these animals were attended by the veterinarians, between 1996 and 2005, none of them presented symptoms suggesting leptospirosis. The most frequent reasons for the visit were loss of weight, unwillingness for work, parasitism, laminess, and wounds. Microscopic Seroagg...
Detection of Leptospira interrogans DNA and antigen in fixed equine eyes affected with end-stage equine recurrent uveitis. Equine recurrent uveitis (ERU) is the most frequent cause of blindness in horses worldwide. Leptospira has been implicated as an etiologic agent in some cases of ERU and has been detected in fresh ocular tissues of affected horses. The objective of this study was to determine the presence of Leptospira antigen and DNA in fixed equine ocular tissues affected with end-stage ERU. Sections of eyes from 30 horses were obtained. Controls included 1) 10 normal equine eyes and 2) 10 equine eyes with a nonrecurrent form of uveitis. The experimental group consisted of 10 eyes diagnosed with ERU based on...
Recurrent uveitis in horses: vitreal examinations with ultrastructural detection of leptospires. This study documents the examination of 17 horses (both sexes, 3-18 years old) suffering from spontaneous equine recurrent uveitis (ERU). Vitreal samples obtained by pars plana vitrectomy were examined macroscopically and ultrastructurally, and in most cases also by cultural examination, by microscopic agglutination test (MAT) and by polymerase chain reaction. In 24% (4/17) of the animals, ultrastructural examination by electron microscopy revealed intact leptospiral bacteria in the vitreous. The leptospires were detected freely in the vitreous and also incorporated by a phagocyte. They were s...
[Detection of leptospira in the vitreous body of horses without ocular diseases and of horses with equine recurrent uveitis (ERU) using transmission-electron microscopy]. Equine recurrent uveitis (ERU) is caused by persistent intraocular leptospira, which appear to use the vitreous body as a refuge. The detection of leptospira in the vitreous body of horses with spontaneous ERU by histological methods has not yet been described. Thirty eight vitreous body samples from 36 horses with ERU (collected during vitrectomy), and 10 vitreous body samples obtained from 5 horses without ocular disease (control group) were examined by transmission electron microscopy. Prior to sample collection, 2 ml of a leptospira culture suspension were injected into the vitreous body o...
Immunohistochemical identification and pathologic findings in natural cases of equine abortion caused by leptospiral infection. The aim of this study was to examine the utility of immunohistochemistry (IHC) in the diagnosis of leptospiral equine abortion and to compare IHC to silver staining and serology of the aborted mares. Ninety-six fetuses from 57 farms were examined using all 3 diagnostic techniques, revealing evidence of leptospiral infection in 3 fetuses (3.1%) from 3 (5.3%) different farms. A new finding in 1 of these confirmed cases of leptospiral abortion was the presence of macroscopic pinpoint grayish-white nodules that had a histologic correlate of hepatic necrosis; other histologic findings were consiste...
Identification of pathogenic Leptospira strains in tissues of a premature foal by use of polymerase chain reaction analysis. Studies were carried out to determine the cause of death in a prematurely born Thoroughbred foal that died 24 hours after birth. Necropsy revealed gross lesions suggestive of septicemia. A commercial Leptospira polymerase chain reaction (PCR) assay designed to specifically amplify the hemolysis-associated protein 1 (hap1) gene present only in pathogenic Leptospira strains detected the presence of Leptospira DNA in various tissues of the foal. Histologic examination of lung, liver, kidney, and myocardium revealed numerous spirochetes in Warthin-Starry-stained tissue sections. Results of PCR ana...
LruA and LruB, novel lipoproteins of pathogenic Leptospira interrogans associated with equine recurrent uveitis. Recurrent uveitis as a sequela to Leptospira infection is the most common infectious cause of blindness and impaired vision of horses worldwide. Leptospiral proteins expressed during prolonged survival in the eyes of horses with lesions of chronic uveitis were identified by screening a phage library of Leptospira interrogans DNA fragments with eye fluids from uveitic horses. Inserts of reactive phages encoded several known leptospiral proteins and two novel putative lipoproteins, LruA and LruB. LruA was intrinsically labeled during incubation of L. interrogans in medium containing [14C]palmiti...
Funisitis associated with leptospiral abortion in an equine placenta. Funisitis, inflammation of the umbilical cord, is well recognized in human placentas. This report describes a case of funisitis associated with leptospiral infection in the placenta of a Thoroughbred foal born prematurely. The umbilical cord had diffuse superficial yellow discoloration along its entire length. Microscopic evaluation showed an exudate of neutrophils admixed with fibrin on the surface. Warthin-Starry staining showed spirochetes in the Wharton's jelly of the umbilical cord. A locally extensive, severe placentitis not involving the star and allantoic cystic hyperplasia were the ot...