Disease etiology in horses refers to the study of the causes and development of diseases within equine populations. It encompasses various factors, including genetic predisposition, environmental influences, infectious agents, and nutritional imbalances, that contribute to the onset and progression of diseases in horses. Understanding disease etiology is essential for identifying risk factors and implementing preventative measures in equine health management. This topic includes research on pathogen-host interactions, the impact of management practices on disease incidence, and the role of genetic and environmental factors in disease susceptibility. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, contributing factors, and implications of disease etiology in horses.
Geraghty TE, Love S, Taylor DJ, Heller J, Mellor DJ, Hughes KJ.A total of 102 horses that had a catheter introduced intravenously to facilitate treatment had the catheterised jugular vein and contralateral vein examined by ultrasound every 48 hours. Subclinical complications were defined by thrombus formation or thickening of the venous wall, and the data were analysed to establish risk factors for the development of these complications. The horses with a rectal temperature above 38.5 degrees C when the catheter was introduced were four times more likely to develop complications, than the horses with a lower temperature. The administration of a NSAID whil...
Odoi A, Carter CN, Riley JW, Smith JL, Dwyer RM.To develop an early-warning automated surveillance-data-analysis system for early outbreak detection and reporting and to assess its performance on an abortion outbreak in mares in Kentucky. Methods: 426 data sets of abortions in mares in Kentucky during December 2000 to July 2001. Methods: A custom software system was developed to automatically extract and analyze data from a Laboratory Information Management System database. The software system was tested on data on abortions in mares in Kentucky reported between December 1, 2000, and July 31, 2001. The prospective space-time permutations sc...
Dumoulin M, Pille F, Van den Abeele AM, Haesebrouck F, Oosterlinck M, Gasthuys F, Martens A.The objective of this study was to evaluate an automated blood culture system for the isolation of microorganisms from infected equine synovial fluid (SF). Samples were collected from 220 severely inflamed synovial joints and classified as either presumably infected (group A: n=149) or not infected (group B: n=71), based on a combination of clinical history, clinical signs and cytological analysis of the SF. Samples were inoculated into blood culture bottles and after incubation were subcultured onto agar media to confirm the results and to facilitate full bacterial identification. Microorgani...
Hackett ES, Hassel DM.Colic is a serious disease of the horse and may require surgical correction. Postoperative complications may result in an increase in short-term morbidity and mortality. Commonly encountered nonsurgical complications are detailed. Anticipation and timely treatment of common postoperative complications after colic surgery may improve overall survival.
Freeman DE.Guttural pouch diseases pose serious challenges in diagnosis and treatment. Complications from treatment are common and often life-threatening, largely because the unique anatomy of the guttural pouches brings them into intimate contact with the nervous, respiratory, and cardiovascular systems. There is little forgiveness for surgical errors, and so the surgeon should focus on ways to anticipate and prevent them. As with any disease, errors in diagnosis can set the stage for many surgical errors and must be recognized. This article deals with errors that can be expected after the most common s...
Davis J, Garner MG, East IJ.In 2007, an incursion of equine influenza (EI) occurred in Australia. Accurate maps of property boundaries were used to examine the pattern and mechanism of local spread of EI. This study focussed on a cluster of infected premises (IPs) at Park Ridge, a peri-urban suburb 26 km south of Brisbane, Queensland. The cluster recorded 437 IPs and 81% of these were not contiguous to a previously IP. The mean distance from each new IP to the closest previous IP was 0.85 +/- 1.50 km with a range of 0.01-12.94 km. Eighty-two percent of new IPs were within 1 km of a previous IP. The spatial mean for each ...
Ferguson R, van Dreumel T, Keystone JS, Manning A, Malatestinic A, Caswell JL, Peregrine AS.An 8-year-old horse was presented with a submandibular swelling. Biopsy of the lesion indicated granulomatous osteomyelitis due to Halicephalobus gingivalis. In the absence of evidence of involvement of the central nervous system at the time of diagnosis, the horse was treated with ivermectin. Unfortunately, the horse did not survive. Un cheval âgé de 8 ans a été présenté pour une enflure sous-mandibulaire. Une biopsie de la lésion a révélé une ostéomyélite granulomateuse causée par En l’absence de signes d’atteinte du système nerveux central au moment du diagnostic, le c...
Todhunter KH, Perkins NR, Wylie RM, Chicken C, Blishen AJ, Racklyeft DJ, Muscatello G, Wilson MC, Adams PL, Gilkerson JR, Bryden WL, Begg AP.A series of abortions occurred in mares in New South Wales during 2004 that involved similar and unusual findings on post mortem examination of aborted fetuses and fetal membranes. The term Equine Amnionitis and Fetal Loss (EAFL) was developed to describe the condition. This form of abortion had not been previously recognised in Australia. The pathology alone is not specific for EAFL and diagnosis requires demonstration of a combination of certain pathological and bacteriological features. The purpose of this paper is to describe patterns considered consistent with EAFL cases as a working case...
Faleiros RR, Nuovo GJ, Belknap JK.Laminar inflammation is one of the earliest events in equine laminitis. Calprotectin (CP), a Damage-Associated Molecular Pattern protein, is overexpressed in inflammatory conditions of human skin. Objective: CP is overexpressed in the laminar epidermis of horses with black walnut extract (BWE)-induced laminitis. Methods: Twenty adult horses. Methods: Experimental study. Horses were allocated to one of 4 groups. BWE was administered to horses in 3 groups, which were sampled 1.5, 3, and 12 hours (LAM) later. CP was visualized by immunohistochemistry. Laminar leukocyte counts and intensity of lam...
Gates MC, Boston RC.Identifying risk factors for West Nile virus transmission is vital for future public health control measures. This study investigated the effect of irrigation, expressed as percent irrigated land, and population density on the incidence of human and veterinary West Nile virus (WNV) cases using a sample of 2827 counties from the United States over a 3-year period. Zero-inflated Poisson regression models were selected because of the large number of counties reporting zero cases. The mean percentage of irrigated land for the entire sample was approximately 0.029, while counties reporting both hum...
Zhu D, Zeng ZL, Peng D, Chen X, Zhao LB, Zhang YY, Xu MM, Zhan QL, Yu JP, Xie P.To investigate the epidemiological pattern of Borna disease virus (BDV) infection in horses and to analyze the phylogenetic tree of derived BDV in Yili, Xinjiang. Methods: We established a modified nested RT-PCR (nRT-PCR) to detect BDV p24 segment in peripheral blood mononuclear cells (PBMCs) and brain tissues of 120 horses in Yili, Xinjiang. Positive products were analyzed by sequencing and homology analysis. Results: The positive rate of BDV infection was 2.5% in both PMBCs and brain tissues at the same time. The gene sequence revealed in positive PCR samples was more than 93%, identical to ...
Timoney JF, Kumar P.Little is known about entry and subsequent multiplication of Streptococcus equi following exposure of a susceptible horse. This information would have value in design of intranasal vaccines and understanding of shedding and protective immune responses. Objective: To determine entry points and sites of subsequent replication and dispersion of S. equi at different times after intranasal infection or commingling exposure. Methods: Previously unexposed horses and ponies were subjected to euthanasia 1, 3, 20 or 48 h following intranasal inoculation with biotin labelled or unlabelled S. equi CF32. S...
Hahn CN, Matiasek K, Dixon PM, Molony V, Rodenacker K, Mayhew IG.Recurrent laryngeal neuropathy (RLN) is a common and debilitating peripheral nerve disease of horses, but it remains unclear if this disease is a mono- or polyneuropathy. An understanding of the distribution of the neuropathological lesions in RLN affected horses is fundamental to studying the aetiology of this very significant disease of tall horses. Objective: To determine whether RLN should be classified as a mono- or polyneuropathy. Methods: Multiple long peripheral nerves and their innervated muscles were examined systematically in 3 clinically affected RLN horses Results: Severe lesions ...
Fosgate GT, Cohent ND.The primary purposes of epidemiological investigations are to learn about causal mechanisms related to disease incidence and identify factors for therapy and prevention. Epidemiological studies can be observational--further categorised as descriptive or analytical--or experimental. Investigators performing experimental studies, or randomised controlled trials (RCTs), randomly assign treatments or exposures to study participants for the expressed purpose of the study. The most frequently encountered observational epidemiological studies employed to investigate issues of equine health are cohort...
Declercq J, Martens A, Maes D, Boussauw B, Forsyth R, Boening KJ.The objective of the present study was to determine clinical and arthroscopic characteristics associated with dorsoproximal proximal phalanx (P1) fragments in Warmblood horses, as well as to examine their histopathological appearance. One hundred sixty-eight fragments were removed from 150 fetlocks of 117 Warmblood horses. Details of signalment and results of clinical examination were collected prior to surgery. After arthroscopic fragment removal and joint evaluation for synovial and/or cartilage abnormalities, the fragments were measured and evaluated histopathologically. The vast majority o...
Veronesi F, Moretta I, Moretti A, Fioretti DP, Genchi C.A study was carried out to assess the field efficacy of ivermectin (IVM) and pyrantel pamoate (PYR) against Parascaris equorum. Seventy-three foals (3-18 months old) from 5 stud farms, not treated with anthelmintics in the previous 10 weeks and with individual faecal egg counts (FEC) >200, were included in the study. For each stud farm, 5-7 foals were included in the IVM-treatment group (IVM 0.2%, 200 mcg/kg body weight) or in the PYR-treatment group (PYR 38%, 13.2mg/kg body weight) and 3 were untreated as controls. For each foal, FECs were carried out before treatment (Day 0) and on Days 7 an...
De Cock HE, Van Brantegem L, Affolter VK, Oosterlinck M, Ferraro GL, Ducatelle R.Chronic progressive lymphoedema (CPL) in horses, a disease of certain draught breeds, is associated with altered elastin metabolism. The characteristic lesions are seen in the skin of the lower (distal) limbs. This study was based on horses of susceptible breeds, with and without CPL, and on horses of a non-susceptible breed. Skin samples were obtained for examination from the neck (considered a non-affected region) and from the distal limb. The skin lesions were characterized histologically and the dermal elastic fibres were evaluated morphologically and quantitatively. In all horses the mean...
Stevens KB, Marr CM, Horn JN, Pfeiffer DU, Perkins JD, Bowen IM, Allan EJ, Campbell J, Elliott J.The effect of left-sided valvular regurgitation (LSVR) on the mortality of middle-aged and older horses was investigated in a prospective cohort study involving 19 yards and 1153 horses. The horses were examined to determine whether they had a cardiac murmur and its type, and their age, sex, breed type and occupation were recorded. They were followed up at intervals of two years by postal questionnaire, and after four years information on 773 horses was available. There was no significant difference in the mortality of the horses with and without LSVR, but small horses had a significantly high...
Baratt RM.Radiography is an important imaging modality and is available to most equine veterinarians providing primary care. Diagnostic radiographic imaging of the equine skull and dentition requires careful positioning and technique. This article is aimed at providing the veterinarian with instructions and guidelines for obtaining diagnostic skull and dental radiographs and a discussion of the radiographic signs of dental disease with case-based examples. The limitations of radiography are discussed with regard to determining the need for adjunct diagnostic techniques and more advanced imaging techniqu...
Johnston JK, Freeman DE.Displacements and intraluminal obstructions of the large colon carry a good to excellent prognosis for long-term recovery, and surgery for these diseases is rarely followed by short-term or long-term complications. Entrapment of the large colon over the renosplenic ligament is amenable to medical therapies so that surgery can be avoided in many cases. However, preoperative diagnosis of all nonstrangulating diseases of the large colon can be difficult. Vascular diseases of the large colon, such as thromboembolic diseases and large colon volvulus, are more difficult to treat and carry a poorer p...
Scholes SF, Holliman A, May PD, Holmes MA.Fell pony foals developed a syndrome of anaemia, immunodeficiency and peripheral ganglionopathy. They became ill in the second or third week, and died in the second or third month of life. Clinical and pathological investigations revealed severe anaemia associated with small numbers of late erythroid precursors in bone marrow, small thymi, an absence of secondary lymphoid follicles, a lack of plasma cells and neuronal chromatolysis involving trigeminal, cranial mesenteric and dorsal root ganglia. Some of the foals had cryptosporidial enteritis and adenoviral bronchopneumonia and pancreatitis. ...
Lampe V, Dierks C, Komm K, Distl O.In this study we present a newly detected QTL associated with osteochondrosis in Hanoverian warmblood horses on equine chromosome 18 (ECA18). We developed a highly polymorphic and evenly distributed marker set on ECA18 employing the horse genome assembly EquCab2. The marker set included 11 newly developed microsatellites. Average polymorphism information content was 62.1% at an average spacing of 3 Mb. For genotyping of this marker set comprising a total of 27 highly polymorphic microsatellites, we used the same 14 paternal half-sib families as in the previous whole genome scan. The chromosome...
Weiss R, Böhm KH, Mumme J, Nicklas W.Over a thirteen year period (1965 to 1977) a total of 4790 skin scrapings and hair samples of animals were examined mycologically. 887 strains of dermatophytes were isolated out of 885 of these samples (= 18,5%). Most frequently Trichophyton verrucosum was identified in samples from cattle, followed by Microsporum canis isolated from cats, dogs and zoo animals. T. mentagrophytes was mainly found on guinea pigs, chinchillas and dogs and T. equinum on horses. Although the total number of the samples examined within the last 8 years increased, the total of the dermatophytes isolated remained prop...
Cummings E, James ER.Of 664 horses reported to have originated in southeastern and midwestern United States, 341 (51.4%) were positive for Onchocerca cervicalis cutaneous microfilariasis. The highest prevalence of 68.8% was recorded for horses from Virginia. Horses with the highest concentrations of microfilariae (as high as 19,770 microfilariae/mg in 1 horse) were from the Southeast (Georgia, Florida, Tennessee, and Alabama). For horses from South Carolina, the prevalence of infection was 57.1%; from the Midwest (Kentucky, Illinois, Ohio, and Indiana), 54.4%; from North Carolina, 45.5%; from Pennsylvania, 7.7%; a...
Paradis MR.Septicemia is the second most commonly diagnosed problem in the equine neonate, superseded only by the problem of inadequate transfer of maternal antibodies. This article reviews the factors that may put a foal at high risk for developing sepsis, the diagnostic tools used to identify these animals, some of the sequelae of sepsis, and the therapeutic modalities available to the clinician.
Tenter AM, Otte MJ, Gonzalez CA, Abuabara Y.Eighty-two equine sera from 13 farms in northern Colombia were examined for antibodies to Babesia caballi and B. equi using the complement fixation (CF) and the indirect fluorescent antibody (IFA) test. Seroreactors to both piroplasms were present on all farms. The IFA test indicated a prevalence of 90% for B. caballi and 94% for B. equi. The CF test detected antibodies to B. caballi in 41% and to B. equi in 65% of the animals. The prevalence of seroreactors in different age groups revealed a significant decline in CF antibodies to B. caballi in animals older than three years. IFA titres for b...
Sweeney RW, Hamir AN, Fisher RR.A 9-year-old Thoroughbred mare was examined because of pollakiuria, hematuria, and weight loss of 3 weeks' duration. Physical examination revealed a regular cardiac rhythm with occasional premature contractions, and a soft tissue mass in the pelvic canal palpable per rectum. Microscopic examination of urine sediment revealed numerous RBC and a large population of lymphocytes and lymphoblasts with characteristics of neoplasia. Similar cells were found in peritoneal fluid obtained by abdominocentesis. The horse was euthanatized without treatment. Necropsy revealed a soft tissue mass infiltrating...
Platt H.A series of 10 haemorrhagic polyps of the equine nasal cavity is described. The lesions show haematoma formation, abundant haemosiderin in macrophages and giant cells, and organising fibrous tissue. In one case, angiomatoid lesions were observed in the mucous membrane of the paranasal sinuses and it is suggested that some haemorrhagic nasal polyps may originate from pre-existing haemangiomatous areas in the respiratory mucosa.
Lan Y, Li Y, Yu G, Zhang Z, Irshad I.Accumulating studies indicated that gut microbial changes played key roles in the progression of multiple diseases, which seriously threaten the host health. Gut microbial dysbiosis is closely associated with the development of diarrhea, but gut microbial composition and variability in diarrheic horses have not been well characterized. Here, we investigated gut fungal compositions and changes in healthy and diarrheic horses using amplicon sequencing. Results indicated that the alpha and beta diversities of gut fungal community in diarrheal horses changed significantly, accompanied by distinct ...
Ayala-Valdovinos MA, Galindo-García J, Sánchez-Chiprés D, Duifhuis-Rivera T.Hydrocephalus in Friesian horses is an autosomal recessive hereditary disease that can result in an abortion, a stillbirth, or euthanization of a newborn foal. Here, the hydrocephalus-associated c.1423C > T mutation in B3GALNT2 gene was detected with PCR-RFLP and PCR-PIRA methods for horse genotyping. A preliminary genotyping survey was performed on 83 randomly selected Friesian stallion horses to determine the current allele frequency in Mexico. The frequency of the mutant T allele was 9.6%.