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.
DOLL ER, WALLACE E, RICHARDS MG.Manninger and Csontos reported that mares inoculated with equine abortion virus developed a transient fever 2 to 4 days after pharyngeal or intravenous inoculation and that an uninoculated horse in contact with the experimentally inoculated mares contracted a febrile disease resembling equine influenza. Also, mares that had aborted virus-infected fetuses were resistant to inoculation with equine influenza virus. From these observations, they proposed that virus abortions were a manifestation of infection of pregnant mares by the equine influenza virus. In reports on equine virus abortions, Kre...
CRAWFORD M.This disease has a very long history, with the earliest written description by Vegetius in the fourth century A.D. It has many names, such as periodic ophthalmia, recurrent ophthalmia, iridocyclitis, uveitis, moon-blindness, etc. Periodic ophthalmia is perhaps the name more generally used, but I prefer to use recurrent iridocyclitis because (a) there is no definite fixed period between the recurrent attacks and (b) because the essential lesion is iridocyclitis.
Gerras J, Young K, Roberts D, Waldman G, Salmon JH, Gilger BC.To describe the ocular findings, chronology of disease, and serum leptospiral titers in a group of horses, mules, and donkeys following an outbreak of leptospirosis. Unassigned: Fifty Equidae in central North Carolina had ophthalmic examinations and serum leptospiral microscopic agglutination test (MAT) titers performed every 3-6 months for 24 months followed by a final examination at 34 months. Unassigned: Throughout the nearly three-year study period, 17 horses (34%; 17/49 horses) developed signs of uveitis; 20 eyes (20/34; 58.8%) of these 17 horses were visual at the initial examinati...
Styková E, Valocký I, Kačírová J, Fecskeová LK.Equine pastern dermatitis (EPD) is a multifactorial disease with a change in the skin microbiome. The present study monitored the influence of Weissella cibaria Biocenol™ 4/8 D37 CCM 9015 stabilized on alginite on the skin microbiota of healthy horses and model patients with EPD. Based on clinical signs, EPD lesions were identified as exudative or proliferative forms. A comparison of the initial microbial community based on 16S rRNA amplicon sequencing revealed that there was a statistically significant difference between healthy vs. exudative (R = 0.52, p = 0.003) and exudative vs. ...
Chakraborty A, Dutta P, Amrit R, Dey P, Osborne WJ.Endosymbiotic bacteria are known to synthesize bioactive compounds which have biotechnological potentials that enhance immune responses by stimulating the production of immune cells. Horse milk is widely known to have nutraceutical and antimicrobial activities; however, there are no scientific reports on its inhibitory effects. VITAPRJS1, isolated from horse milk, showed non-hemolytic properties and was significantly tolerant to bile salt and NaCl. The isolate also exhibited potent antibacterial activity against pathogenic bacterial strains such as Escherichia coli, Pseudomonas aeruginosa, Sta...
Jacob O, Hause B, Peters-Smith K, Adam EN, Page AE, Floyd C, Tucker C, Eertink LG, Wang D, Li F.Equine sarcoids are the most identified skin tumors of horses, which are highly associated with bovine papillomavirus infection. Sarcoids can impair the use of the horse and are difficult to treat, resulting in significant economic losses and a welfare concern. There is no vaccine available to protect global equines from sarcoids. We aimed to determine the safety and protective antibody response in horses immunized with a recombinant baculovirus vector vaccine expressing the L1 protein of bovine papillomavirus type 1 (BPV1). A group of 10 clinically healthy, sarcoid-free horses were immunized ...
O'Kennedy MM, Reedy SE, Abolnik C, Khan A, Smith T, du Preez I, Olajide E, Daly J, Cullinane A, Chambers TM.Equine influenza (EI) is a highly contagious acute respiratory disease of wild and domesticated horses, donkeys, mules, and other Equidae. EI is caused by the Equine Influenza virus (EIV), is endemic in many countries and outbreaks still have a severe impact on the equine industry globally. Conventional EI vaccines are widely used, but a need exists for a platform that facilitates prompt manufacturing of a highly immunogenic, antigenically matched, updated vaccine product. Here we developed a plant-produced bivalent EI virus-like particle (VLP) vaccine candidate which lacks the viral genome an...
Shnaiderman-Torban A, Meltzer L, Zilberman-Daniels T, Navon-Venezia S, Cohen A, Sutton GA, Blum SE, Amit S, Steinman A.Infections with extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) contribute to morbidity and mortality in human neonates. In foals, data are scarce. Objective: Determine the association between ESBL-PE gastrointestinal colonization on hospital admission and infections in hospitalized neonates. Methods: Sixty-seven foals. Methods: Prospective study of foals admitted to a veterinary hospital. Foals were screened for ESBL-PE colonization and for infections. Risk factors and clinical outcomes were analyzed. Results: Seventy-six percent of foals suffered from at least 1 bacteri...
Fernandes TA, Paulino PG, Dos Santos Juliano D, Rabello CA, de Oliveira NVB, de Souza Santana M, Peckle M, Massard CL, da Costa Angelo I, Jacob JCF....Equine piroplasmosis (EP) is a reportable disease according to the World Organization for Animal Health (WOAH), caused by Babesia caballi, Theileria equi and T. haneyi. This syndrome is prevalent in tropical and subtropical regions, including various areas in Brazilian. This study examines EP in the Distrito Federal, Brazil, focusing on prevalence, epidemiological characteristics, and circulating genotypes. Epidemiological data and whole blood samples were collected from horses in the Distrito Federal. DNA was analyzed using qPCR for Theileria sp. and B. caballi, followed by cPCR for 18S rDNA ...
Isgren CM, Pinchbeck GL, Salem SE, Hann MJ, Townsend NB, Cullen MD, Archer DC.Surgical site infection (SSI) is a frequent complication following emergency equine laparotomy, negatively impacting equine welfare, increasing treatment costs and presenting a hospital biosecurity risk. Objective: To determine if a sutured-on stent dressing for incisional protection during anaesthetic recovery reduced SSI following emergency laparotomy. Methods: Randomised controlled trial. Methods: Eligible horses were randomised to a sutured-on stent (intervention) or textile dressing (control) as the primary component of a 3-layer abdominal bandage placed for anaesthetic recovery. Horses w...
Macías-Rioseco M, Ochoa J, Choi EA, Blanchard P, Moeller RB, Uzal FA. spp. can cause gastroenteritis, hepatitis, bacteremia, and abortions in domestic animals and humans. Some spp. are zoonotic. To our knowledge, hepatitis caused by has not been reported in horses. Here we present a case of acute necrosuppurative hepatitis caused by infection in a 3-y-old gelding, and we review the literature on infections in various animal species. The horse had a one-week history of weight loss and weakness before becoming recumbent and dying. Grossly, the liver had rounded edges and was mottled. There were ecchymoses on the gastric serosa, and a large amount of mucoid, p...
Hardefeldt LY, Thomas K, Begg L.Antimicrobial resistance (AMR) is a problem for equine practitioners in Australia, but antimicrobial use in practice has been largely understudied. We aimed to evaluate equine veterinarians' intentions of prescribing antimicrobials in areas where we perceived there to be wide ranges of practice - dentistry, reproduction and for nonbactericidal effects. Methods: An online cross-sectional survey of veterinarians working in equine practice was conducted over 4 months in 2023 and 2024. Antimicrobial use, including compounding practices, for reproductive and dental disorders, and nonbactericidal...
Sijtsema M, Stringer T, Hopman NEM, van der Graaf-van Bloois L, Duim B, van den Brom-Spierenburg A, Theelen M, Zomer A, Broens EM.Healthcare-associated infections (HAIs) associated with ESKAPEE pathogens are an emerging concern in equine hospitals, especially in the intensive care unit (ICU). To gain insight into the occurrence of HAIs and to identify potential reservoirs and transmission routes of ESKAPEE pathogens in an equine ICU, a pilot study of two periods (December 2022-January 2023 and April-June 2023) was performed, where patient and environmental samples were obtained upon ICU admission and discharge. A sampling and laboratory protocol for the detection and identification of different ESKAPEE pathogens and Salm...
Schiele AR, Valletti C, Ringer SK.A Trotter mare (aged 5 years 8 months) presented with severe thoracic limb lameness 2 years after screw fixation of a third carpal bone fracture. Septic arthritis of the intermediate carpal joint necessitated three anaesthetics: two arthroscopic lavages in dorsal recumbency, followed by a computed tomography-guided screw explantation with curettage of an infected, sclerotic third carpal bone in right lateral recumbency. For each anaesthetic, maintenance was with isoflurane carried in oxygen and air, and a medetomidine constant rate infusion. Twelve days after the third anaesthetic, the horse h...
Yu H, Raymonda JW, McMahon TM, Campagnari AA.This article reviews the recent development of two solid-phase chemiluminescence-based techniques, fluorogenic-chemiluminescence (FCL) and electro-chemiluminescence (ECL) for detection of biological threat agents. Both techniques entail a labeled sandwich immunoassay. The objectives of this work are to develop advanced techniques for sensitive and effective detection of a target analyte, particularly in cases where the analysis includes complex samples containing multiple contaminating factors. Other important considerations in developing such detection techniques include the ease of use, the ...
Sun Y, Yu YT, Castillo XO, Anderson R, Wang M, Sun Q, Tallmadge R, Sams K, Reboul G, Zehr J, Brown J, Wang X, Marra N, Stanhope B, Grenier J....Fever of unknown origin (FUO) without a respiratory component is a frequent clinical presentation in horses. Multiple pathogens, both tick-borne and enteric, can be involved as etiologic agents. An additional potential mechanism is intestinal barrier dysfunction. This case-control study aimed to detect and associate microbial taxa in blood with disease state. Areas known for a high prevalence of tick-borne diseases in humans were chosen to survey horses with FUO, which was defined as fever of 101.5°F or higher with no signs of respiratory illness or other recognisable diseases. Blood samples ...
Talib MT, Nasir A, Kashif M, Rahman A, Rehman AU, Akbar H, Nadeem A, Howe DK, Azam MN.The aim of this study was to determine the prevalence of anti-Neospora (N.) caninum and anti-N. hughesi antibodies in horses and to appraise the associated risk factors in the two central districts (Jhang and Toba Tek Singh) of Punjab Province, Pakistan. A total of 300 horse sera were analyzed for the presence of antibodies to Neospora spp. using a competitive ELISA. The overall prevalence of antibodies against Neospora species in horses was 25 % (75/300; 95 % CI 20.1-29.9). The prevalence of antibodies to N. caninum and N. hughesi species was 12.3 % (37/300; 95 % CI 8.6-16) and 19.3 % (5...
Tsujimura K, Bannai H, Kambayashi Y, Nemoto M, Ohta M.Equid alphaherpesvirus 1 (EqAHV1; Orthoherpesviridae, Varicellovirus equidalpha1) spreads by viremia to susceptible organs. Because EqAHV1 circulates in the bloodstream in a cell-associated manner, serum samples are not considered valuable for detecting EqAHV1 and have therefore not been tested by highly sensitive detection methods such as real-time PCR (rtPCR). We investigated whether EqAHV1 could be detected by this method in equine serum samples. We performed rtPCR on archived sera and peripheral blood mononuclear cells (PBMCs) collected from 3 horses experimentally inoculated with EqAHV1. ...
Abdelnaby EA, ElKader NAA, Yehia SG, Salem NY, Ramadan ES, Khattab MS, Farghali HA, Emam IA.This study aimed to demonstrate the vaginal tissue alterations via vaginal biopsy and hemodynamic alterations by introducing chromoendoscopy to analyse the effect of equine vaginitis on the oxidative and hormonal profile. Mares were divided into normal mares (N = 10) and affected mares (N = 10). Animals were subjected to Doppler ultrasonographic evaluation, endoscopic examination, oxidative stress was estimated, and biopsy samples were taken for histopathology and immunohistochemistry. Uterine body (UB) thickness (mm), circumference (mm) and area (mm) elevated significantly in infected...
Martins AS, Romanowski TNA, Campos JS, Vieira RC, Silva TA, Borsanelli AC.Brucellosis is a zoonosis caused by bacteria of Brucella genus, which affects domestic and wild animals and humans. In horses, the infection can be caused by Brucella canis, Brucella suis or Brucella abortus, through the ingestion of contaminated food, contact of bacteria with skin wounds or through the respiratory tract, manifesting with signs such as fistulous withers and reduced performance. The present study aimed to evaluate the seroprevalence of Brucella abortus infection in equids in the state of Goiás. Sampling was carried out on 299 farms across 132 municipalities, with a total of 89...
Brys M, Claerebout E, Saey V, Chiers K.A cross-sectional study was conducted to estimate the prevalence of chorioptic mange affecting the distal legs of horses in Belgium, focusing on the association between mange and chronic progressive lymphedema (CPL) in Belgian draft horses. Clinical examinations and skin scrapings were performed on the distal legs of 156 Belgian draft horses and 142 Belgian warmblood horses. In the Belgian draft horse breed, 144 (92.31%) horses were infested with Chorioptes bovis mites, and 126 (80.77%) displayed clinical signs of CPL. CPL prevalence in draft horses aged < 1 year was 17.86%, while mites we...
Griessel TS, Muñoz Morán JA, Byaruhanga C, Smit Y.Surgical site infection (SSI) is a significant cause of postoperative morbidity following equine laparotomy. Therefore, if risk factors for SSI can be identified, morbidity may consequently be reduced. The objectives of this study were to determine the prevalence of SSI in horses undergoing exploratory laparotomy at a single hospital over an 8-year period (2013‒2021), investigate the risk factors associated with SSI and report on the bacterial isolates identified. Methods: The medical records of horses that had an exploratory laparotomy performed at the teaching hospital due to colic were r...
Bain ME, Alsop EJ, Knox CA, Tweedie MA, Knottenbelt DC.Mycobacterium ulcerans infection in horses is under-reported. Objective: To document the successful multimodal treatment of M. ulcerans and highlight the need for further investigation due to the zoonotic nature of M. ulcerans with its related potential public health concerns. Methods: Case report CASE DESCRIPTION: A 14-year-old gelding in the Southeastern region of Australia was diagnosed with M. ulcerans infection, initially presenting as a non-healing wound of the right flank progressing to extensive necrotic ulceration. Ziehl-Neelsen and Wade-Fite stained incisional biopsies revealed large...
Kawanishi N, Kinoshita Y, Reedy SE, Garvey M, Kambayashi Y, Bannai H, Tsujimura K, Yamanaka T, Cullinane A, Chambers TM, Nemoto M.Equine influenza virus (EIV) is one of the most important pathogens causing respiratory signs in equids. Rapid antigen detection (RAD) kits are useful for point-of-care testing because they are user-friendly and provide fast results. Although sensitive and broad-reactive RAD kits are needed for controlling horse movement, no RAD kits specified for EIV are available. Objective: This study evaluated the usefulness of seven RAD kits originally developed for human influenza and available in Japan during 2023-2024 for EIV antigen detection. Methods: Experimental assay comparison. Methods: The detec...
Peris MP, Serrano M, Romero A, García M, Halaihel N, Castillo JA, Gracia MJ.Equine piroplasmosis (EP), a tick-borne disease caused by Babesia caballi and Theileria equi, is of significant concern due to its impact on the international horse trade. According to standards established by the World Organisation for Animal Health (WOAH), horses imported from EP-endemic regions must have a certificate confirming negative serological and molecular test results. In EP-free countries, only seronegative horses are allowed to enter. This entails economic losses for endemic regions such as Spain. Our study aimed to assess the prevalence of B. caballi and T. equi in horses from no...
Marchi S, Amodeo D, Peccetti B, De Palma I, Messina G, Montomoli E, Trombetta CM.Influenza D virus (IDV) is a novel influenza virus, first isolated from swine with influenza-like symptoms in the USA in 2011. To date, IDV circulation has been reported in various animal species such as cattle, pigs, horses with the ability to expand its range of hosts. UV radiation has been widely used for the disinfection of various sources such as water, air, and surfaces, especially in places at greater risk of contamination by viruses and bacteria, such as hospitals and health facilities. The aim of this study was to evaluate the potential virucidal effect of a violet-blue light against ...
Uprety T, Swan M, Kennedy L, Bryant U, Cassone L, Loynachan A, Janes J, Evely MM, Calvaruso FC, Quick M, Morgan J, Abdelrazek S, Lahmers K, Carter C....Clostridium piliforme is an obligate intracellular filamentous bacterium that causes Tyzzer disease (TD) in many animals. The disease manifests as severe, multifocal necrotizing hepatitis, with a high fatality rate in foals. Through retrospective investigation, we detected C. piliforme in 43 equine necropsy cases from 2012 to 2024. Positive cases were diagnosed from February to July, peaking in May. The age of affected foals ranged from 4 days to 2 months. Histologically, all cases had necrotizing hepatitis with multifocal, coalescing pinpoint, tan or reddish foci. Since only a partial 16S rRN...
McNabb L, McMahon A, Woube EG, Agnihotri K, Colling A, Broder CC, Kucinskaite-Kodze I, Petraityte-Burneikiene R, Bowden TR, Halpin K.Hendra virus (HeV) is a bat-borne zoonotic agent which can cause a severe and highly fatal disease and can be transferred from animals to humans. It has caused over 100 deaths in horses since it was discovered in 1994. Four out of seven infected humans have died. Since the release of the HeV vaccine (Equivac® HeV Hendra Virus Vaccine for Horses, Zoetis Australia Pty Ltd., Rhodes, NSW 2138) in Australia, there has been an urgent requirement for a serological test for differentiating infected from vaccinated animals (DIVA). All first-line diagnostic serological assays at the Australian Centre f...
Pusterla N, Lawton K, Barnum S, Magdesian KG.In recent years, the use of non-invasive host and environmental samples for the detection and monitoring of equine respiratory pathogens has shown promise and a high overall agreement with the gold standard of nasal secretions. The present study looked at comparing nose wipes, stall sponges, and air samples with nasal swabs collected from 27 horses involved in an equine influenza (EI) outbreak. The outbreak involved 5 clinical, 6 subclinical, and 16 uninfected horses. Samples sets were collected at the onset of the index case and retested every 2-3 days thereafter until all horses tested qPCR-...
Płoneczka-Janeczko K, Armstrong E, Siemieniuch-Tartanus M, Magdziarz M.The aim of the study was to explore and characterise healthy foals' eye microbiomes in the first two months of life. Unassigned: Conjunctival swabs were collected three times, not later than 12 h after delivery and again at the end of the first and the second months of life from six clinically healthy foals of the Polish Konik breed. The average interval between the first and second samplings was 33.3 days and between the second and third was 35.6 days. Next-generation sequencing performed on a MiSeq sequencer in paired-end technology was used to analyse the composition of the conjunctival mic...
Simms N, Bertone JJ, Melgarejo T, O'Shea C, Linde A.Emerging research suggests the presence of a blood microbiome in clinically healthy individuals. Characterizing bacterial composition and abundance in blood from a group of healthy horses is of clinical interest. Objective: Horses in a closed herd environment will have blood microbiomes with similarities among individuals. Methods: Twenty trail-riding horses of different breeds and ages living in relative isolation on a dry lot pasture in Colorado at 7680 ft elevation. Methods: Cross-sectional study. Blood was collected from the jugular vein into serum, blood collection, and EDTA tubes. Samp...
Polo MC, Huby FD, Uehlinger FD, Rubin JE.Antimicrobial resistance is a serious threat in human and veterinary medicine. Among the most problematic resistant organisms are the extended-spectrum β-lactamase (ESBL)-producing Enterobacterales, which are resistant to the 3rd-generation cephalosporins. The purpose of this study was to determine the frequency of colonization of horses admitted to the Western College of Veterinary Medicine with resistant Escherichia coli. Unassigned: Rectal swabs were collected from 60 horses admitted between November 2021 and March 2022. Swabs were selectively cultured for E. coli, which was identified usi...
