Epidemiology in horses involves the study of the distribution and determinants of health-related states and events in equine populations. It encompasses the investigation of patterns, causes, and effects of diseases and health conditions within horse populations. This field of study aims to identify risk factors for disease and targets for preventive healthcare. Key components of equine epidemiology include disease surveillance, outbreak investigation, and the study of disease dynamics within herds or regions. Research in this area often focuses on infectious diseases, zoonotic diseases, and the impact of environmental factors on equine health. This page compiles peer-reviewed research studies and scholarly articles that explore various aspects of epidemiology in horses, including disease prevalence, transmission pathways, and strategies for disease prevention and control.
Munroe G.Over 80 per cent of 169 neonatal thoroughbred foals had some part of the hyaloid artery present bilaterally and its degree of completeness, colour and character was statistically symmetrical. The complete artery was present in over 60 per cent of the foals. The incidence of the hyaloid artery and its completeness, colour and character were related to the age of the foal. The hyaloid system atrophies in the early stages of the neonatal period and generally its presence did not cause any significant ocular problems. The presence and morphology of the posterior pupillary membrane was highly corre...
Atwill ER, McDougald NK, Perea L.Faecal specimens from 305 horses and mules used as packstock at one of 17 commercial or governmental (National Park Service, US Forest Service) operations were examined for Giardia duodenalis and Cryptosporidium parvum using immunofluorescent microscopy. Fourteen packstock (4.6%) were shedding G. duodenalis cysts, with herd-level prevalences ranging 0-22%. Number of packstock in the corral, size of corral and density of packstock in the corral were associated with the odds of shedding G. duodenalis cysts. None of the horses had detectable C. parvum oocysts. Assuming a sensitivity of at least 4...
Björnsdóttir S, Axelsson M, Eksell P, Sigurdsson H, Carlsten J.The prevalence of degenerative joint disease (DJD) in the distal tarsal joints and the relation between radiographic and clinical signs compatible with the disease were estimated in a population of Icelandic horses used for riding. The material consisted of 614 horses age 6-12 years (mean age = 7.9 years). Radiographs with 3 projections of each tarsus were made and a clinical examination, including palpation of the medial aspect of the distal tarsus and motion evaluation of the hindlimbs before and after a flexion test of the tarsus, was performed. Radiographic signs of DJD in the distal tarsa...
Pusterla N, Leutenegger CM, Sigrist B, Chae JS, Lutz H, Madigan JE.A real-time quantitative PCR using the TaqMan fluorogenic detection system (TaqMan PCR) was established for identification of Ehrlichia risticii, the agent of Potomac horse fever (PHF). The TaqMan PCR identified an 85 base pair section of the 16S rRNA gene by use of a specific fluorogenic probe and two primers. This technique was specific for eight tested E. risticii strains. The TaqMan system identified 10 copies of a cloned section of the 16S rRNA gene of E. risticii. The sensitivity and specificity of the TaqMan PCR were similar to those of conventional nested PCR. The TaqMan PCR was evalua...
Bullock PM, Ames TR, Robinson RA, Greig B, Mellencamp MA, Dumler JS.Equine granulocytic ehrlichiosis (EGE) is caused by infection with Ehrlichia equi. EGE has been reported primarily in northern California, where E equi is transmitted by the tick Ixodes pacificus. Reports of EGE and the emergence of human granulocytic ehrlichia in Minnesota prompted a seroprevalence study of E equi in horses of Minnesota and Wisconsin. Tick (Ixodes scapularis) endemic areas of Minnesota and Wisconsin were compared to nonendemic regions of Minnesota. Indirect fluorescent antibody was used to detect the presence of serum antibodies to E equi. Serum samples from healthy horses, 3...
Rashmir-Raven AM, Black SS, Rickard LG, Akin M.Papillomatous digital dermatitis is a common disease in cattle. The pastern dermatitis observed in a horse shared many of the gross characteristics of papillomatous digital dermatitis in cattle. Lesions included a mixture of proliferative and erosive changes, with a verrucose appearance in some areas. Microscopic similarities included pseudoepitheliomatous and papillomatous epidermal hyperplasia with hyperkeratosis, spongiosis of the epidermis, and intraepidermal spirochetes. The horse was also concurrently infected with Pelodera strongyloides. Papillomatous digital dermatitis in cattle is ass...
Yates P, Mumford JA.To investigate the level of cross-protection induced by equine influenza H3N8 vaccines derived from different lineages, two studies have been carried out with ponies vaccinated with 'American-like' and 'European-like' vaccines and experimentally challenged with a European-like strain. The results demonstrated that equine influenza vaccines clearly protect against challenge with homologous virus if serum antibody titres are sufficiently high. On the other hand, protection is incomplete even when animals vaccinated with heterologous strains have comparative antibody levels. Nevertheless, the pro...
Kim L, Morley PS, McCluskey BJ, Mumford EL, Swenson SL, Salman MD.To report clinical and serologic findings in horses with oral vesicular lesions that were consistent with vesicular stomatitis (VS) but apparently were not associated with VS virus (VSV) infection. Methods: Serial case study. Methods: 8 horses. Methods: Horses were quarantined after appearance of oral lesions typical of VS. Severity of clinical signs was scored every 2 to 5 days for 3 months. Serum samples were tested for antibodies by use of competitive ELISA (cELISA), capture ELISA for IgM, serum neutralization, and complement fixation (CF). Virus isolation was attempted from swab specimens ...
Renshaw RW, Glaser AL, Van Campen H, Weiland F, Dubovi EJ.A virus that could not be identified as a previously known equine virus was isolated from the mononuclear cells of a horse. Electron microscopy revealed enveloped virions with nucleocapsid structures characteristic of viruses in the Paramyxoviridae family. The virus failed to hemabsorb chicken or guinea pig red blood cells and lacked neuraminidase activity. Two viral genes were isolated from a cDNA expression library. Multiple sequence alignments of one gene indicated an average identity of 45% as compared to Morbillivirus N protein sequences. A weaker relationship was found with Tupaia paramy...
Bailey CJ, Reid SW, Hodgson DR, Rose RJ.To determine whether sex or foaling period were associated with time to first race start and whether sex, age at time of first race start, or inter-race period were associated with career duration for Thoroughbred racehorses in Australia. Methods: 553 Thoroughbred racehorses. Methods: Race records through to the end of the 6-year-old racing season were obtained for each horse. Product-limit survival analysis was used to determine whether sex or foaling period was associated with time to first race start and whether sex or age at first race was associated with career duration. A Cox proportiona...
van Maanen C, Willink DL, Smeenk LA, Brinkhof J, Terpstra C.An outbreak of EHV1 abortions occurred at a riding school in The Netherlands in 1991. Seven of twelve pregnant mares aborted, and another foal died at 8 days of age. Six abortions occurred within 12 days in March after an initial abortion on 8 February. Four mares delivered live foals. Virological examination of four aborted foals revealed an EHV1 infection. Serological results for paired sera from 17 horses suggested, that the initial abortion on 8 February was the index case, and probably caused the other six abortions. The index case could well have been caused by reactivation of latent vir...
Tencza SB, Islam KR, Kalia V, Nasir MS, Jolley ME, Montelaro RC.The control of equine infectious anemia virus (EIAV) infections of horses has been over the past 20 years based primarily on the identification and elimination of seropositive horses, predominantly by a standardized agar gel immunodiffusion (AGID) assay in centralized reference laboratories. This screening for EIAV-seropositive horses has been to date hindered by the lack of a rapid diagnostic format that can be easily employed in the field. We describe here the development of a rapid solution-phase assay for the presence of serum antibodies to EIAV based on fluorescence polarization (FP) (pat...
van Maanen C, Vreeswijk J, Moonen P, Brinkhof J, de Boer-Luijtze E, Terpstra C.Ten monoclonal antibodies (MAbs) were produced against equine herpes virus type 1 (EHV1). Two appeared type-specific, while the other eight were directed against epitopes common to both EHV1 and EHV4. Two MAbs directed against the glycoprotein gp2 recognized linear epitopes, as demonstrated by Western blotting. With pools of type-specific MAbs, 282 field isolates were typed in an immunoperoxidase monolayer assay (IPMA). From a total of 254 fetal or neonatal isolates, 244 (96%) were typed as EHV1, whereas 14 out of 15 (93%) respiratory tract isolates were typed as EHV4. Surprisingly, 3 out of 1...
Friday PA, Scarratt WK, Elvinger F, Timoney PJ, Bonda A.An outbreak of neurologic disease associated with serologic evidence of equine herpesvirus type 1 (EHV-1) infection occurred in a herd of 46 riding school horses. Ataxia and paresis were observed in 14 geldings and 5 barren mares. Eight affected horses had distal limb edema, 1 horse had a head tilt, and 3 others had urinary incontinence. Other clinical signs included fever, depression, and inappetance in 30 horses. Seven horses with neurologic signs were treated with acyclovir. Serum neutralizing antibody titers against EHV-1 increased 4-fold between acute and convalescent samples or exceeded ...
Cohen ND, Berry SM, Peloso JG, Mundy GD, Howard IC.To determine the association between high-speed exercise and risk of injury while racing among Thoroughbreds in Kentucky. Methods: Matched case-control study. Methods: 206 Thoroughbreds that sustained a musculoskeletal injury while racing and 412 Thoroughbreds that were not injured during the same races. Methods: Data regarding official timed workouts and races and the Beyer's numbers for the 3 races before the race during which injury occurred were extracted from past performance charts and compared between injured horses and control horses. Results: For injured horses, cumulative distance of...
Fleury C, Bérard F, Leblond A, Faure C, Ganem N, Thomas L.An epidemiological survey was made on cutaneous melanomas occurring in Camargue-type, gray-skinned horses in southern France. The population investigated was composed of 264 horses, which were selected from the Camargue horse stud registry and were allowed to be examined by the owners. The presence of tumors was inspected macroscopically according to the standardized protocols of veterinary medicine specialists, and some tumors were subjected to macroscopic histopathological examination. The results indicated that: 1) the prevalence of melanomas in the overall population was 31.4%; 2) the odds...
Kihurani DO, Masake RA, Nantulya VM, Mbiuki SM.Following an outbreak of trypanosomosis in horses on a farm in Kenya, 18 trypanosome isolates were collected from the infected animals over a period of one and a half years and cryopreserved for characterization. The characterization was done on the basis of morphology using Giemsa-stained blood and buffy coat smears, infectivity to mice, recombinant DNA hybridization, and chromosome separation by orthogonal field alternation gel electrophoresis (OFAGE). Morphologically, all the trypanosome isolates were identified as belonging to the subgenus Nannomonas, and a total of 16 out of the 18 isolat...
Borges LM, Oliveira PR, Ribeiro MF.Anocentor nitens is a widespread ectoparasite of horses in Brazil. A study of the seasonal dynamics of the parasitic phase of this tick was made by regular census of engorging females (>/=4mm) on free-ranging horses, fortnightly from July 1995 to July 1997, at Pedro Leopoldo, Minas Gerais. Twenty horses were divided into four groups of five animals per group, each having a similar mix of resistant and less resistant animals, based on initial infestation. Every 2 weeks, one of the groups, in sequence, was treated with an acaricide to prevent excessive infestations, and female ticks were cens...
Lunn DP, Townsend HG.Equine infectious disease remains a constant and important threat to the health of domesticated horses. Vaccination plays a critical role in protecting against such disease, but at the present time the efficacy of some equine vaccination strategies is in doubt. The best strategy for resolving these concerns is an improved knowledge of the immunologic basis of successful vaccination, combined with the appropriate integration of effective vaccines into well-designed disease control policies.
Klei TR.Helminths are among the most significant parasites of horses in developed countries. This article examines immune responses against helminth parasites and the implications that immunologic investigations have on vaccine development, improvement of diagnostic procedures, and disease eradication.
Giangaspero A, Tieri E, Otranto D, Battistini ML.A survey on the prevalence of Thelazia spp. in Abruzzo region (Italy) in slaughtered native horses was conducted from August 29, 1997 to August 28, 1998. Both eyes from 128 eight-month to 11 year-old native animals were examined. 50 horses (39.06%) were found parasitized by Thelazia lacrymalis. 502 specimens (371 females, 88 males and 12 larvae) were collected. In the infected horses the numbers of T. lacrymalis ranged from 1 to 48, with a mean count burden of 3.92 per head (SD = 7.79). T. lacrymalis specimens were mainly in the excretory ducts of the Harderian gland, and also in the ducts of ...
Collins MN, Friend TH, Jousan FD, Chen SC.Three groups of slaughter-type horses, totaling 30 mares and 29 geldings, were used to determine density effects on displacement (distance moved during a stop), falls, injuries, and orientation using a single-deck, open-topped commercial semi-trailer. Each horse was assigned to one of two treatments: high density (1.28 m(2)/horse with 14 horses) or low density (2.23 m(2)/horse with eight horses). Both treatments occurred sequentially on the same day (treatment order was alternated each trial), using the middle 2.44x7.32 m compartment of a large semi-tractor trailer. The horses were transported...
LeBlanc MM, Neuwirth L, Jones L, Cage C, Mauragis D.The position of the uterus within the abdomen may affect a mare's ability to rapidly clear the uterine lumen of contamination. In this study, the position of the uterus was determined from left and right lateral flank scintigrams taken 1 and 2 h after intrauterine infusion of radiocolloid. Scintigraphy was performed during estrus in 44 mares, 24 were reproductively normal and 20 exhibited a delay in uterine clearance. Reproductively normal mares were nulliparous (n = 14) or pluriparous (n = 10), 3 to 21 yr of age, had no history of persistent uterine infections and cleared > 50% of a radioc...
Sorli JM.To determine the demographics of hospital admissions and mortality associated with equestrian activities in the 33,000 riders in British Columbia (BC). Methods: Analysis of admission data from the Ministry of Health for the years 1991-96, review of information obtained from the Office of the Chief Coroner, and comparison of data from Canadian Hospitals Injury Reporting and Prevention Program. Results: The mean number of admissions per year was 390. Head injury was the most common cause of admission to hospital (20%) in BC. Females most often required admission (62%). Teenagers and children hav...
Mainar-Jaime RC, House JK, Smith BP, Hird DW, House AM, Kamiya DY.To predict mortality of horses by use of clinical data from the first day of hospitalization, to determine whether fecal shedding of Salmonella organisms is related to severity of clinical disease, and to determine the impact of fecal shedding of Salmonella organisms on mortality. Methods: Prospective study. Methods: 1,446 hospitalized horses. Methods: Medical information was obtained from horses hospitalized in an intensive care unit or isolation facility during a 4.5-year period. A model was created to predict mortality, using covariates determined on the day of admission. Predicted mortalit...
Yepez-Mulia L, Arriaga C, Viveros N, Adame A, Benitez E, Ortega-Pierres MG.In order to determine the presence of Trichinella infections in horses slaughtered at an abattoir in Mexico, 147 serum samples were examined by two immunoenzymatic methods. Specific antibodies were detected by ELISA in 7% of the serum samples at a dilution 1:400 and in 10% at lower dilutions (1:20, 1:40) using Trichinella spiralis muscle larvae (ML) excretory/secretory (E/S) products. Serum samples from four naturally infected horses (confirmed by direct methods) gave negative O.D. values in an ELISA at a 1:400 dilution and only two of them were positive at a 1:20 and 1:40 dilutions. Serum sam...
Blythe LL, Mattson DE, Lassen ED, Craig AM.Neutralizing antibodies against equine herpesvirus 1 were measured in serum and cerebrospinal fluid of 16 horses and ponies from a closed herd both before and after vaccination with modified live equine herpesvirus 1. These titers were also measured in 22 neurologically normal and 15 neurologically abnormal horses at a teaching hospital. Animals from the closed herd had prevaccination serum titers up to 1:8 and postvaccination serum titers up to 1:128. Horses from the teaching hospital had serum titers up to 1:64. Cerebrospinal fluid titers were not detected in the vaccinated horses or the neu...
Barton AK, Troppenz A, Klaus D, Lindenberg I, Merle R, Gehlen H.There is contradictory evidence on the potential benefits of tongue ties on upper airway function and their efficacy in inhibiting intermittent dorsal displacement of the soft palate (DDSP) in racehorses. Objective: To test the hypothesis that tongue ties increase the pharyngeal diameter and decrease the occurrence of dynamic airway obstruction in racehorses. Methods: Prospective, crossover blinded clinical study. Methods: Data of 22 Thoroughbred and 8 Standardbred racehorses examined using overground endoscopy under full-intensity exercise on training racetracks with and without fixation of t...
Chung C, Wilson C, Timoney P, Balasuriya U, Adams E, Adams DS, Evermann JF, Clavijo A, Shuck K, Rodgers S, Lee SS, McGuire TC.The objective of the present study was to validate a previously described competitive enzyme-linked immunosorbent assay (cELISA) to detect antibody to Equine arteritis virus (EAV) based on GP5-specific nonneutralizing monoclonal antibody (mAb) 17B7(9) using the World Organization for Animal Health (OIE)-recommended protocol, which includes the following 5 in-house analyses. 1) The assay was calibrated with the OIE-designated reference serum panel for EAV; 2) repeatability was evaluated within and between assay runs; 3) analytical specificity was evaluated using sera specific to related viruses...
Hampson BA, Owens E, Watts KA, Mills PC, Pollitt CC, de Laat MA.To determine the impact of a free-choice diet on nutritional intake and body condition of feral horses. Methods: Cadavers of 41 feral horses from 5 Australian locations. Methods: Body condition score (BCS) was determined (scale of 1 to 9), and the stomach was removed from horses during postmortem examination. Stomach contents were analyzed for nutritional variables and macroelement and microelement concentrations. Data were compared among the locations and also compared with recommended daily intakes for horses. Results: Mean BCS varied by location; all horses were judged to be moderately thin...
Christensen BW, Roberts JF, Pozor MA, Giguere S, Sells SF, Donahue JM.A 4-year-old Thoroughbred mare was evaluated because of placental abnormalities and a retained placental remnant. Results: Microbial culture of the placenta yielded pure growth of Amycolatopsis spp. Histologic examination of the placenta revealed a focally expanding chorionitis with intralesional gram-positive filamentous bacilli and multifocal allantoic adenomatous hyperplasia on the apposing allantoic surface. Results: Treatment with lavage and oxytocin resulted in expulsion of the placental remnant within hours of parturition. The mare did not become pregnant again despite multiple breeding...
Bailey RE, Dyson SJ, Parkin TD.The aims of this study were to establish the frequency of occurrence, intensity and symmetry of focal increased radiopharmaceutical uptake in the dorsoproximal aspect of the diaphysis of the proximal phalanx; to determine if this focal increased radiopharmaceutical uptake was related to age, height, gender, breed, bodyweight, or discipline of the horse, and if there was any relationship with lameness. Scintigraphic images from 690 horses were analyzed subjectively and objectively. Age, breed, discipline, height, weight, gender, and lame limb(s) or reasons for presentation were recorded for all...
Lloyd S.Between 30 and 70 per cent of horses at 18 stables had their anthelmintic treatments withdrawn for a year. Three of the stables (group 1) had used no anthelmintics for many years, 10 (group 2) had treated their horses with anthelmintics approximately twice a year, and five (group 3) had used anthelmintics five to seven times a year. A total of 1068 samples of faeces were collected from the 267 untreated horses and faecal egg counts were carried out four times during the year. Overall 50.2 per cent of the samples contained less than 200 epg. When the four counts from individual horses were coll...
Vostry L, Vostra-Vydrova H, Citek J, Gorjanc G, Curik I.Inbreeding depression is the reduction of performance caused by mating of close relatives. In livestock populations, inbreeding depression has been traditionally estimated by regression of phenotypes on pedigree inbreeding coefficients. This estimation can be improved by utilising genomic inbreeding coefficients. Here we estimate inbreeding depression for insect bite hypersensitivity (IBH) prevalence, the most common allergic horse disease worldwide, in Old Kladruber horse. In a deep pedigree with 3214 horses (187 genotyped), we used a generalised linear mixed model with IBH phenotype from 558...
Dai F, Riva MG, Dalla Costa E, Pascuzzo R, Chapman A, Minero M.To identify feasible indicators to evaluate animals' emotional states as a parameter to assess animal welfare, the present study aimed at investigating the accuracy of free choice profiling (FCP) and fixed list (FL) approach of Qualitative Behaviour Assessment (QBA) in horses during the loading phase of transport. A total of 13 stakeholders were trained to score 2 different sets of videos of mixed breed horses loaded for road transport, using both FCP and FL, in 2 sessions. Generalized Procustes Analysis (GPA) consensus profile explained a higher percentage of variation (80.8%) than the mean o...
Glace BW, Kremenic IJ, Hogan DE, Kwiecien SY.Equestrians have a high risk of concussions per hospital records. However, most concussions occur in private settings where concussions are not tracked. We determined concussion incidence by self-report, expressed per 1000 h of exposure, and determined helmet usage and concussion knowledge. Methods: Descriptive epidemiological study. Methods: Equestrians were recruited using a snowball method of sampling in which enrolled participants recruited more equestrians. Participants completed a survey of equestrian experience and history of concussion, symptoms and provided estimates of hours spent ...
Reinemeyer CR, Herd RP.The large intestines of 6 horses were divided by length into 12 segments, and each segment was washed and weighed. At least 5% by weight of each segment was examined by mural transillumination, and encysted cyathostome larvae were counted. Total numbers of larvae in each segment were calculated. Encysted larvae (98%) were present in the proximal 7 segments of the large intestine (cecum and proximal 75% of the ventral colon), and 2% were present in the distal 25% of the ventral colon and entire dorsal colon. Encysted larvae (6%) were located in the dorsal colon of 1 heavily infected horse. Larv...
Bimson NH, Morrice-West AV, Wong ASM, Hitchens PL, Rocca MR, Whitton RC.Catastrophic musculoskeletal injuries (CMI) pose a major welfare concern to horses and their riders, yet limited data are available describing their occurrence in South America. Using a retrospective cohort and case-control design, the objective of the study was to determine the incidence of CMI for Thoroughbreds in training and racing, and associated horse-level risk factors in Uruguay. Seventy-seven Thoroughbreds sustained a CMI, 37 of which were age- and sex-matched to 111 control horses in the same race. Training and racing data from 2011 to 2017 were collected. Incidence of race day CMI p...
Chalder RH, Knott T, Rushton JO, Nikolic-Pollard D.To identify temporal changes in antimicrobial resistance of ocular surface bacteria isolated from clinically symptomatic equine eyes in the South West of the UK. Methods: Retrospective. Methods: Clinical and laboratory records of horses treated for suspected bacterial ocular surface disease (ulcerative and non-ulcerative) at a single facility between January 2011 and December 2019 were reviewed. Cases were included if they underwent ocular surface sampling, aerobic bacterial culture, and antimicrobial susceptibility testing. Cases were split into two time periods based on when sampling occurre...
House JA.African horse sickness (AHS), which causes mortality up to 95%, is caused by orbiviruses and is transmitted by Culicoides. The goal of a control and eradication program for AHS is to prevent the spread of the virus via the biological vector. Control measures include slaughter of infected animals, housing of suspected infected animals in insect-proof stalls, and vaccination. Vaccination has played a key role in eradication when AHS occurred outside of Africa. Both modified live vaccines (MLV) and inactivated vaccines have been used to control AHS. An acceptable vaccine should be: safe, efficaci...
Timoney PJ, O'Reilly PJ, McArdle JF, Ward J, Harrington AM, McCormack R.Reproduction of contagious equine metritis 1977 in Pony mares was achieved with cultures of an unclassified Gram-negative coccobacillus. Infected mares developed a vaginal discharge and associated inflammatory changes of the cervix and vagina. There was evidence of variation in pathogenicity between different strains of the organism. Although all infected mares made spontaneous clinical recoveries, the Gram-negative coccobacillus persisted in the genital tracts of a considerable proportion for a variable period after challenge. Recovery of the organism was not associated solely with the occurr...
Lord CC, Venter GJ, Mellor PS, Paweska JT, Woolhouse ME.African horse sickness (AHS) and equine encephalosis (EE) viruses are endemic to southern Africa. AHS virus causes severe epidemics when introduced to naive equine populations, resulting in severe restrictions on the movement of equines between AHS-positive and negative countries. Recent zoning of South Africa has created an AHS-free zone to facilitate equine movement, but the transmission dynamics of these viruses are not fully understood. Here, we present further analyses of serosurveys of donkeys in South Africa conducted in 1983-5 and in 1993-5. Age-prevalence data are used to derive estim...
Sellon DC, Levine JF, Palmer K, Millikin E, Grindem C, Covington P.The records of horses presented to the Veterinary Teaching Hospital of North Carolina State University College of Veterinary Medicine between January 1, 1989 and April 30, 1994 were evaluated to determine risk factors associated with thrombocytosis. Of the 2,346 horses for which a CBC was performed, 24 (1.0%) had a platelet count > 400,000/microL. Demographic, diagnostic, physical examination, and clinicopathologic variables from these cases were compared with a reference population consisting of 189 horses with a normal platelet count presenting during the same period. Infectious/ inflamma...
van den Ingh TS, Hartman EG, Bercovich Z.A Leptospira interrogans serogroup australis serovar lora infection in a stud farm is reported. During three successive years (1984-1986) clinical leptospirosis with a severe often rapid, fatal course was seen in 12 foals. Clinical examination revealed severe respiratory distress, depression and pyrexia. Other symptoms were diarrhea (2), jaundice (1), and an unsteady gait (1). Morphological characteristics of the disease were massive pulmonary haemorrhage and haemorrhagic-thrombotic or extracapillary glomerulonephritis with tubulonephrosis and interstitial oedema. In most foals high or increas...
Muñoz L, Donaire C, Salazar T, Ortiz R, Cruces J, Briones M.The Chilean horse is a breed of closed registry. Stall-walking and weaving are locomotor stereotypies that affect this breed, and genetic predisposition has been suggested for both conditions. The objective of the present study was to estimate heritability of stall-walking and weaving in Chilean horses. Owners of 2,098 horses registered in the Chilean horse Stud Book, which were or had been stabled for at least 1 year, were asked to provide for identification data of the animal and presence or absence of stall-walking and/or weaving. The Chilean Horse Stud Book was accessed online, to collect ...
Beech J.Despite major advances in our knowledge and ability to treat respiratory diseases in neonatal foals, neonatal respiratory medicine is still in its infancy. It is hoped that this article may serve as a guideline for diagnosis and treatment. Specific antibiotic regimens and emergency procedures are covered in other articles in this symposium. Because management factors play a critical role in the pathogenesis of respiratory disease, education of clients as to their importance would help both prophylactically and therapeutically. The necessity of very careful monitoring of neonates, which is crit...
Marchiondo AA, White GW, Smith LL, Reinemeyer CR, Dascanio JJ, Johnson EG, Shugart JI.Clinical field trials were conducted at five geographical locations in the USA (Oklahoma, Wisconsin, Tennessee, Virginia and Idaho) to evaluate the efficacy and safety of pyrantel pamoate paste (19.13%, w/w, pyrantel base) administered at the recommended dosage of 13.2 mg pyrantel base/kg (6.0 mg pyrantel base/lb) body weight (b.w.) against tapeworm infections of Anoplocephala spp. in naturally infected horses. Horses at each study site were allocated by restricted randomization based on the cestode status (positive or negative) of pre-treatment fecal egg counts to complete sets of four animal...
Morley PS, Traub-Dargatz JL, Benedict KM, Saville WJ, Voelker LD, Wagner BA.Equine protozoal myeloencephalitis (EPM) is a serious and often fatal neurologic disease of horses, but few studies have investigated risk factors. Objective: To evaluate operation- and individual-level factors associated with likelihood of the occurrence of EPM. Methods: Data were collected as part of a study of the US equine industry from 1,178 operations representing 83.9% of horses and 51.6% of operations with > or =3 horses in 28 states. Methods: Probability-based sampling was used to enroll representative operations in a cross-sectional study. Interviews were conducted to collect info...
Dauparaitė E, Kupčinskas T, Hoglund J, Petkevičius S.Anthelmintic resistance (AR) in equine cyathostomins is being reported all over the world. In Lithuania, however, the last study on this subject was published more than fifteen years ago, thus little is known about the current situation. The aim of this study was to determine the factors that may associated with the development of AR on equine studs in Lithuania. A questionnaire containing seven open-ended and nine closed multiple-choice questions about worm control strategies, use of anthelmintic substances and stable management practices was posted to 71 randomly selected horse establishment...
Cranley JJ, McCullagh KG.The hearts and aortas of 2076 unselected horses of all ages were examined immediately after slaughter. Focal zones of fibrosis, observed in the myocardium of 14.3 per cent of hearts examined, were found in both atria and ventricles and were unrelated to age. Microscopically the majority of lesions involved myocardial fibre lysis and replacement fibrosis, although acute infarction was present in some cases. Intramyocardial arterioles in or adjacent to the lesions exhibited occlusive arteriosclerotic changes whereas those elsewhere remained patent. The evidence strongly suggests that the myocard...
Orr EL, Staniar WB, Smarsh DN.Various aspects of nutritional management can impact both a horse's gastrointestinal (GI) health and caretaker costs. The objective of this study was to characterize the feeding management and GI issues of horses in Pennsylvania (PA). An online survey was distributed from February 27th to August 31st, 2020. Kruskal-Wallis and Mann-Whitney tests were used to analyze the data. Nonparametric statistics were used when data were not normally distributed. From 470 responses collected, the average horse age was 15.7 ± 7.5 years, and the most common breeds were the Quarter Horse and Thoroughbred. Of ...
Eysker M, Jansen J, Kooyman FN, Mirck MH, Wensing T.The small strongylid infections of two groups of three yearling female Shetland ponies and one yearling Shetland tracer pony were studied. One group was set stocked from April to November and was treated monthly with 5 mg kg-1 albendazole from two days before turnout until July. The other group grazed similar pasture until July, was treated with 5 mg kg-1 albendazole and subsequently removed to pasture grazed by sheep from April to July. The tracer ponies were added to both groups in September. The efficacy of both methods was not completely satisfactory probably because of low efficacy of ant...
Ikinger CM, Baldamus J, Spiller A.Human interactions with horses entail certain risks. Although the acceptance and use of protective gear is increasing, a high number of incidents and very low or inconsistent voluntary use of safety equipment are reported. While past studies have examined factors influencing the use of safety gear, they have explored neither their influence on the overall safety behavior, nor their relative influence in relation to each other. The aim of the present study is to fill this gap. We conducted an online survey with 2572 participants. By means of a subsequent multiple regression analysis, we explore...
Metz GE, Ocampos GP, Serena MS, Gambaro SE, Nosetto E, Echeverría MG.To perform genetic analysis of the ORF5 of equine arteritis virus (EAV) may provide new insights into the genetic evolution and origin of the Argentinean EAV sequences. Methods: A total of 76 sequences were analyzed by neighbor joining (NJ), maximum parsimony and maximum likelihood algorithms. The analysis of the selective pressures was performed using the Tajima's test. Results: The trees showed similar topologies. Two clades were identified: the first clade was formed by strains isolated mainly from a donkey, whereas the second clade presented four large groups from different geographic regi...
