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.
Amoss HL, Marsh P.Experiments were made for the purpose of testing the reaction of protection against infection as a measure of potency of antimeningococcic serum. The results of the experiments were extremely variable and bore no relation to the quality of the sera as determined by the period of immunization of the horses from which they were obtained, or the indications of efficiency based upon their employment in human cases of epidemic meningitis. The results also failed entirely to conform to the agglutination titer of the sera tested and to be affected by the different type forms of the meningococci. We r...
Inada R, Ido Y, Hoki R, Ito H, Wani H.Horses immunized with cultures of Spirochaeta icterohaemorrhagiae yield an immune serum having therapeutic properties. With rare exceptions the serum destroys completely the spirochetes contained in the circulating blood. The development of antibodies is promoted by the serum injections. The number of spirochetes in the organs is reduced by the treatment. Secondary manifestations due to the serum are slight and disappear promptly. The ultimate effects of the serum treatment on the symptoms and final outcome of the disease have still to be determined.
Atkinson JP.1. The globulins of both normal and diphtheria antitoxic serum exhibit chemically toward reagents the same reactions, being precipitated by magnesium sulphate and split up into fractions in precisely the same way. 2. All of the diphtheric antitoxic power of both normal and immunized serum is always carried by the globulin and its fractional precipitates. 3. During the fractional precipitation of the serum globulin of horses immunized from diphtheria toxin and horses not immunized from diphtheria toxin, some of the globulin is lost, likewise at the same time some of the antitoxic power of the g...
To investigate predictors of survival and athletic function in adult horses with infection of a synovial structure. Objective: Increasing duration from contamination to referral, bone or tendon involvement and positive microbial culture decreases short-term survival. Synovitis and/or sepsis at 5 days post-admission and involvement of Staphylococcus spp. decreases long-term athletic function. Methods: Retrospective study. Methods: Records over 4 years of adult horses with synovial sepsis were reviewed. A two-tailed Fisher's exact test, Mann-Whitney U test or t-test was used to examine whether v...
Although equine herpesvirus myeloencephalopathy (EHM) is a relatively uncommon manifestation of equine herpesvirus-1 (EHV-1) infection, it can cause devastating losses during outbreaks. Antemortem diagnosis of EHM relies mainly on the molecular detection of EHV-1 in nasal secretions and blood. Management of horses affected by EHM is aimed at supportive nursing and nutritional care, at reducing central nervous system inflammation and preventing thromboembolic sequelae. Horses exhibiting sudden and severe neurologic signs consistent with a diagnosis of EHM pose a definite risk to the surrounding...
Faghihzadeh Gorji F, Sadr S, Eshrati H, Borji H.Worldwide, equines are affected by equine filariosis, an endemic vector-borne disease caused by heterogenous parasitic nematodes. The main objective of this study was to determine the prevalence of filarial infection among horses in the North and Northeast of Iran. Between October 2021 and July 2022, 145 equine blood samples were investigated, of which 49 cases were from the northeast and 96 were from the north of Iran. Blood samples were taken for microfilariae using Knott's method. Out of 145 blood samples, only 2 cases (1.37%) from northern Iran were positive for microfilaria of , and no po...
Schilling M, Dunkel B, Floyd T, Hicks D, Nunez A, Steinbach F, Folly AJ, Johnson N.We report fatal West Nile virus (WNV) infection in a 7-year-old mare returning to the United Kingdom from Spain. Case timeline and clustering of virus sequence with recent WNV isolates suggest that transmission occurred in Andalusía, Spain. Our findings highlight the importance of vaccination for horses traveling to WNV-endemic regions.
Cutarelli A, Buonavoglia A, Fusco G, Pellicanò R, Napoletano M, Brandt S, Roperto S.Sarcoids are benign and locally aggressive skin lesions that commonly affect horses and other equid species. Sarcoids are generally considered to be caused by bovine delta-papillomaviruses (δPVs) types 1 and 2 (BPV1 and BPV2, respectively). Moreover, while bovine δPV types 13 and 14 (BPV13 and BPV14, respectively) are also suspected to induce sarcoids, information regarding this possibility and the occurrence of multiple bovine δPV infections in sarcoids is scarce. This study aimed, for the first time, to assess BPV1, BPV2, BPV13, and BPV14 infections and co-infections in equine sarcoid sam...
Leduc L, St-Jean G, Lavoie JP.Antimicrobials are commonly prescribed for the treatment of equine asthma, despite limited evidence supporting their use. Tracheal wash (TW) bacterial culture results are known to influence antimicrobial prescription decisions. Objective: To determine whether a positive TW bacterial culture in horses with asthma is associated with bronchial infection or colonisation, increased bronchial remodelling and airway inflammation by evaluating the presence of bacteria and airway remodelling in endobronchial biopsies, as well as bronchoalveolar lavage fluid (BALF) cytology and tracheal mucus scores. Me...
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...
Hananeh W, Al Rukibat R, Hammad H, Mukbel R.Leishmaniosis is an endemic parasitic infection in Jordan and the Middle East. Despite the endemicity of leishmaniosis in Jordan and frequently reported humancases, no singleclinical case has been documented in animals throughout the country. This report documents the first two animal Leishmania cases in two different animal species with a current literature review. Cutaneous leishmaniosis was diagnosed in an adult horse that presented with multiple variably sized skin nodules, some of which ulcerated. Visceral leishmaniosis was diagnosed in a stray dog. Cytological, histopathological, and mol...
Pineda V, Calzada JE, Montilla S, Rodríguez I, Howard E, Torres AI, Vasquez V, Reina A, Saldaña A, González K. (CL) is a vector-borne zoonotic disease affecting the skin and mucous membranes of animals and humans. While CL is commonly diagnosed and studied in humans in Panama, limited information exists on its occurrence in domestic animals and their potential role as reservoirs. In this study, samples from twelve domestic animals (ten dogs and two horses) with suspected CL lesions were collected between 2021 and 2025 in endemic regions of Panama and evaluated using multiple diagnostic methods. infection was confirmed in six of them (50%): five dogs and one horse. Three dogs were infected with () , ...
Alsakini KAMH, Al-Ammiri HH, Touma MM.A prevalent contagious pathogenic parasite that can lead to major health issues is . Unassigned: The present study aimed to detect the parasitic immune response and the existence of genomic DNA in the blood of a -positive equine. Unassigned: Thirty serum samples from horses suspected of having toxoplasmosis were collected from the Al-Rusafa neighborhood in Baghdad. To quantitatively investigate toxoplasma antibody levels in horse serum, an ELISA was used to evaluate immunoglobulin G (IgG) levels. Conventional (PCR) was used to identify DNA. Unassigned: The blood levels of IgG immunoglobulin i...
Uzal FA, Navarro MA, Asin J, Henderson E.Clostridioides difficile affects humans, and several other animal species, such as horses, pigs, gerbils, guinea pigs, hamsters, and rabbits. This microorganism has also been isolated from the gastrointestinal tract of healthy individuals of a wide variety of animal species in which its association with disease is not known. Traditionally, in most domestic animal species, C. difficile-infection disease (CDI) was antibiotic-associated, although in the past few years more cases in which no antibiotic association was known have been described. In addition, no antibiotic association has been descr...
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...
Basso RM, Cerri FM, Braga PRC, Silva ROS, de Araújo Júnior JP, Oliveira-Filho JP, Pantoja JCF, Ribeiro MG, Arroyo LG, Borges AS.Diarrhea is a significant cause of morbidity and mortality in foals. Our hypothesis is that foals with diarrhea have a greater prevalence of ≥2 organisms causing coinfections. We investigated the major microorganisms associated with diarrhea in 200 foals up to 1-y-old (100 diarrheic and 100 non-diarrheic). Fecal samples were analyzed by real-time PCR (rtPCR) for the detection of and toxin genes and , (genotyping for toxin-encoding genes), spp., , , , , , and spp. Rotavirus A and coronavirus were detected using reverse-transcription rtPCR. Fecal bacterial culture was also performed for ...
Onyiche TE, Peng TL.Potomac Horse Fever (PHF), also known as equine neorickettsiosis (EN) or equine monocytic ehrlichiosis is an acute, potentially fatal infectious disease in horses caused by the monocytotropic rickettsia bacterium Neorickettsia risticii. This obligate intracellular bacterium is maintained throughout the life cycle of digenetic trematodes which utilize multiple intermediate and definitive hosts. Research on N. risticii is scattered across multiple continents, with most studies originating from North and South America. Therefore, a systematic review is needed to consolidate global evidence, clari...
Tau RL, Marandino AE, Panzera Y, Alamos F, Vissani MA, Romera SA, Pérez R, Maidana SS.The Equid alphaherpesvirus type 1 (EHV-1) infection can have devastating economic consequences in the horse industry due to large-scale outbreaks of abortions, perinatal foal mortality, and myeloencephalopathy. The present study analyzed the genome of two isolates obtained from aborted fetuses in Argentina, E/745/99 and E/1297/07. The E745/99 genome shares 98.2% sequence identity with Ab4, a reference EHV-1 strain. The E/1297/07 genome shares 99.8% identity with NY03, a recombinant strain containing part of ORF64 and part of the intergenic region from Equid alphaherpesvirus-4 (EHV-4). The E/12...
Girma T, Chala G, Mekibib B.Epizootic lymphangitis is an infectious and chronically debilitating disease of the equines. Histoplasma capsulatum var. farciminosum, a thermally dimorphic fungi, is the causative agent for the disease. In Ethiopia, the disease significantly affects carthorses, posing threats to animal welfare, and resulting in substantial economic losses. Limited availability of widely accessible antifungals in addition to the chronic nature of the disease is the major challenge against management of epizootic lymphangitis. This study aimed to assess the in vitro efficacy of specific local medicinal plant ex...
Mirabal B, Andrade BS, Souza SPA, Oliveira IBDS, Melo TS, Barbosa FS, Jaiswal AK, Seyffert N, Portela RW, Soares SC, Azevedo V, Meyer R, Tiwari S....Equine strangles is a prevalent disease that affects the upper respiratory in horses and is caused by the Gram-positive bacterium . In addition to strangles, other clinical conditions are caused by the two subspecies, and , which present relevant zoonotic potential. Treatment of infections caused by has become challenging due to the worldwide spreading of infected horses and the unavailability of effective therapeutics and vaccines. Penicillin treatment is often recommended, but multidrug resistance issues arised. We explored the whole genome sequence of 18 isolates to identify candidate p...
Marcelino I, Keizer J, Monti G, Cornelissen P, Santman-Berends I, Lam JH, van der Poel WHM.Monitoring and surveillance of pathogens are crucial for safeguarding animal and public health. While passive surveillance is more common for wild and free-living animals, active monitoring improves the detection and characterisation of specific pathogens relevant to animal and public health. In the (OVP) nature reserve in the Netherlands, an active monitoring system for Heck cattle (), Konik horses () and red deer () has been in place since 1997. This study utilised the data generated from the monitoring system to estimate pathogen prevalence and to evaluate the ongoing monitoring efforts. Y...
Lobato OL, Nogueira TDS, Lima TET, Andrade FJDC, de Macedo MGG, Pereira RS, Xavier J, Amorim MR, Barbosa PP, da Rocha AS, Silva SDC, Alcantara LCJ....The cycle of the Orthoflavivirus nilense (West Nile virus - WNV) involves birds and mosquitoes, while humans and equids serve as terminal hosts. In 2014, the first human case in Brazil was confirmed in Piauí State. Objective: To investigate the presence of WNV in birds, mosquitoes, and equids in municipalities of Piauí. Methods: Collections were carried out following recommendations from the Ministry of Health of Brazil, in 11 municipalities (all with human cases or bird mortality), where biological samples were collected from birds, mosquitoes, and equids. The Viral RNA extraction was perfo...
Zhang Y, Guo X, Yu M, Sun L, Qu Y, Guo K, Hu Z, Liu D, Zhang H, Wang X.Host ANP32 family proteins are crucial for maintaining the activity of influenza RNA polymerase and play an important role in the cross-species transmission of influenza viruses. To date, the molecular properties of equine ANP32 (eqANP32) protein are poorly understood, particularly the mechanisms that affect equine influenza virus (EIV) RNA polymerase activity. Here, we found that there are six alternative splicing variants of equine ANP32A (eqANP32A) with different levels of expression. Further studies showed that these six splicing variants of eqANP32A supported the activity of EIV RNA polym...
Duarte FRSC, Lima FR, Medeiros GC, Furtado LL, Aquino LPCT, Fonteque JH, Moura AB, Chryssafidis AL.Werneckiella equi is an ectoparasite of equids, and control can be challenging because of the limited availability of licensed products. This case report describes the clinical observation of 1% fipronil pour-on against W. equi infestation in horses admitted to a veterinary hospital. Two horses were treated and observed between 2022 and 2023. Both exhibited pruritus, especially in the head, withers, and croup regions, and were diagnosed with severe W. equi infestation. The treatment consisted of a single topical application of 1% fipronil pour-on (1 mg/kg). Parasite reduction was assessed by c...
Sévin C, Duquesne F, Copin S, Raguenet V, Guy M, Wilhelm A, Gassilloud B, Moreau P, Petry S.A retrospective review of equine necropsies performed at the Normandy Laboratory for Animal Health, French Agency for food, environmental and occupational health and safety (1996-2022) unexpectedly reported Vibrio alginolyticus, Vibrio parahaemolyticus and Vibrio vulnificus in equine samples using API 20NE, prompting a re-evaluation of bacterial identification. Of 27 strains, 25 were cultivable, and re-examined using API 20NE, API 20E, MALDI-TOF, 16S rRNA gene sequencing and Vibrio-specific PCR assays. API 20NE confirmed the original (erroneous) identifications; all Vibrio-specific PCR assays ...
Li C, Liu K, Wei N, Hu S, Li X, Li C.RNA viruses, a unique class of life forms, are widely distributed in nature and pose potential health risks. Monitoring the gut RNA virome in livestock is a crucial component of global health surveillance. As important companion animals, horses play a vital role in transportation and make significant contributions to various cultural and economic activities. Nevertheless, the characteristics of horse gut RNA viruses remain largely uncharted. Unassigned: In this study, we used metatranscriptome sequencing and bioinformatics methods to characterize viruses within the gut contents of 16 horses sp...
Wei W, Lan Z, Li C, Liu X, Zhang X, Wang J, Bai X, Zhou L, Wang X, Wang C, Gao J.Babesia species are tick-transmitted hemoprotozoa that infect mammals, birds, and humans, posing a significant global threat to veterinary medicine threat. In this study, the authors systematically retrieved articles on the occurrence of Babesia species in domestic herbivores in China, including ovine, bovine, and equine species, through a search in the following six databases from their inception to 4 November 2024: PubMed, Web of Science, ScienceDirect, Chinese National Knowledge Infrastructure, Wanfang Data, and VIP Chinese Journal Database. A total of 94 studies (54 high-quality studies, 4...
Pirkani Z, Araghi-Sooreh A, Kamalinejad F.We aimed to determine the seroprevalence of in horses in West Azerbaijan Province, Iran a region known for its wildlife interactions. Unassigned: The study was conducted in March 2016 across four cities in West Azerbaijan: Urmia, Chaldoran, Sardasht, and Khoy, Iran. A total of 184 equines, ranging from three to over ten years of age, were randomly sampled. Blood samples were collected and were analyzed using the ID Screen® Indirect Multi-species ELISA to detect antibodies. Unassigned: Of the 184 serum samples, 4 (4.3%) from northern counties and 2 (2.2%) from southern counties tested positi...
Fukumoto N, Shibata M, Hayashi M, Kawauchi K, Yabuuchi Y, Oue Y, Matsuyama R, Yamamoto T, Mita H, Kawanishi N, Bannai H, Tsujimura K, Yamanaka T....In 2025, an outbreak of equine influenza occurred among draft horses at Obihiro Racecourse in Hokkaido, Japan. The number of horses showing clinical signs increased dramatically in April. The proportion affected was significantly higher in 2-year-olds than in older groups. The proportion that developed fever during the outbreak was significantly higher than that observed among Thoroughbreds during the 2007 outbreak. In non-epidemic periods, the geometric mean hemagglutination inhibition antibody titer of 2-year-old draft horses was significantly lower than that of 2-year-old Thoroughbreds. The...
Blangy-Letheule A, Montnach J, Perrier J, Lemonnier LC, Denis M, Rozec B, Lauzier B, Leroux AA.Colic is a leading cause of mortality in horses, particularly when associated with systemic inflammation and organ dysfunction. In human medicine, these complications are associated with sepsis, defined as organ dysfunction caused by a dysregulated, life-threatening host response to infection. However, no consensus sepsis score exists for adult horses. This retrospective study aimed to develop a diagnostic sepsis score for adult horses. Medical records from 295 horses admitted for colic to the Oniris equine emergency department (Nantes, France) between July 2011 and November 2021 were analyzed...
Elsawy BSM, Alzan HF., a recently discovered tick-borne hemoparasite infecting equids globally, has significant implications for equine health. Although it is closely related to (sharing 23% genomic divergence), it establishes an asymptomatic carrier state in persistently infected horses, creating a silent transmission reservoir. Its discovery and unique genetics justify its classification as a new taxon. A critical diagnostic challenge is that the lack of the gene in prevents its detection by the standard cELISA, emphasizing the need for species-specific tools. Although species-specific PCR assays, including ...
Equine trypanosomosis remains an important veterinary concern in regions where horses play a significant economic and cultural role. In Kazakhstan, comprehensive nationwide data on the seroepidemiological status of equine trypanosomes are limited. The aim of this study was to assess the serological distribution of equine trypanosomosis across all administrative regions of Kazakhstan using complement fixation testing (CFT). A total of 6065 equine serum samples were collected from seventeen regions between 2023 and 2025. Antibodies against members of the subgenus were detected using a WOAH-reco...
Shams N, Jaydari A, Khademi P, Eydi J, Sgroi G.Due to the abundance of ticks on open grassy surfaces, racetracks may represent ideal scenarios for tick-borne pathogens. Therefore, in 2024/2025 Turkmen horses (Akhal-Teke breed) and ticks collected by dragging in paddocks of Iran were screened for Anaplasmataceae using Sanger sequencing on 16S rRNA, TRP36 and dsb genes. Amongst 200 horses, 11 (5.5%) tested positive without signs/symptoms, being 8 (4%) for Ehrlichia canis and 3 (1.5%) for Anaplasma ovis; no difference in prevalence was found by gender and age (p>0.05). All ticks were identified as Hyalomma asiaticum and Haemaphysalis sulca...
K-Jánosi K, Sztojka A, Kis IE, Biksi I, Bakos Z, Kaszab E, Mag T, Albert E.In 2024, a highly fatal outbreak of equine salmonellosis occurred in a Hungarian equine referral hospital, resulting in the death or euthanasia of four out of five affected horses. () subsp. serovar Typhimurium was identified as the primary causative agent from equine faecal, reflux, and post-mortem intestinal content samples, while one case involved Coeln. Extensive environmental sampling during the outbreak also yielded multiple serovars. Whole-genome sequencing revealed a high degree of genetic relatedness among the Typhimurium isolates, confirming nosocomial transmission. The source ...
Rodrigues GJ, Monteiro FDO, Teixeira PPM.This case report describes the successful application of video-assisted hysteroscopy to evaluate endometrial recovery in a 6-year-old mare following treatment for complete uterine prolapse secondary to dystocia. Upon presentation, the uterus was manually reduced and supported with a Buhner's suture. A multimodal medical protocol, including broad-spectrum antibiotics, anti-inflammatory drugs and uterine lavage, was initiated. Five days after reduction, an endoscopic evaluation was performed using a dedicated videovaginoscope without uterine insufflation. The procedure provided high-resolution i...
