Disease outbreaks in horses refer to the occurrence and spread of infectious diseases within equine populations. These outbreaks can be caused by various pathogens, including bacteria, viruses, and parasites, and can lead to significant health issues in affected horses. Common diseases that may result in outbreaks include equine influenza, equine herpesvirus, strangles, and equine infectious anemia. The transmission of these diseases can occur through direct contact, environmental exposure, or vectors such as insects. Disease outbreaks can have substantial impacts on horse health, welfare, and the equine industry as a whole. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, transmission dynamics, and management strategies associated with disease outbreaks in equine populations.
Laus F, Preziuso S, Spaterna A, Beribè F, Tesei B, Cuteri V.An outbreak of strangle-like disease involving 26 horses farmed in central Italy was investigated by clinic examination, endoscopy, cytology, bacteriology and polymerase chain reaction (PCR). At weekly interval, a total of three nasal swabs and one guttural pouches lavage fluid (GPLF) were collected, and no Streptococcus equi subsp. equi carrier was found. Some horses showed upper airways disease and endoscopic signs of pharyngeal lymphoid hyperplasia of different grade and/or abnormal endoscopic appearance of guttural pouches. Streptococcus dysgalactiae subsp. equisimilis was isolated from 14...
Venter GJ, Koekemoer JJ, Paweska JT.Confirmed outbreaks of African horse sickness (AHS) occurred in the surveillance zone of the Western Cape in 1999 and 2004, both of which led to a two-year suspension on the export of horses. Light trap surveys in the outbreak areas showed that known vector competent Culicoides species, notably C. imicola, were abundant and present in numbers equal to those in the traditional AHS endemic areas. Isolations of AHS virus serotypes 1 and 7, equine encephalosis virus, and bluetongue virus from field-collected C. imicola in the surveillance zone demonstrated that this species was highly competent an...
Henninger RW, Reed SM, Saville WJ, Allen GP, Hass GF, Kohn CW, Sofaly C.Equine herpesvirus type 1 (EHV-1) infection causes neurologic disease in horses. However, risk factors for the disease and long-term prognosis are poorly characterized. Objective: There are identifiable risk factors for equine herpes-1 myeloencephalopathy. Methods: The entire population of 135 horses housed within the equestrian facility. Methods: A descriptive study investigated the clinical, serologic, virologic, and management aspects of an outbreak of EHV-1 myeloencephalopathy. Results: Out of 135 horses at the facility, 117 displayed signs of EHV-1 infection. Forty-six horses developed ne...
Zhao S, McDermott PF, White DG, Qaiyumi S, Friedman SL, Abbott JW, Glenn A, Ayers SL, Post KW, Fales WH, Wilson RB, Reggiardo C, Walker RD.Three hundred and eighty Salmonella isolates recovered from animal diagnostic samples obtained from four state veterinary diagnostic laboratories (AZ, NC, MO, and TN) between 2002 and 2003 were tested for antimicrobial susceptibilities and further characterized for bla(CMY) beta-lactamase genes, class 1 integrons and genetic relatedness using PFGE. Forty-seven serovars were identified, the most common being S. Typhimurium (26%), S. Heidelberg (9%), S, Dublin (8%), S. Newport (8%), S. Derby (7%), and S. Choleraesuis (7%). Three hundred and thirteen (82%) isolates were resistant to at least one ...
Zhang X, Wang Y, Liang H, Wei L, Xiang W, Shen R, Shao Y.The equine infectious anemia virus (EIAV) donkey-leukocyte attenuated vaccine (DLV) has been used to protect against equine infectious anaemia (EIA) disease for several decades in China. The attenuated mechanism and immunological protective mechanisms remain to be elucidated. To identify responses that correlate with the protection against disease, we immunized horses with DLV, followed by challenge with an EIAV wild-type strain LN. All vaccinated horses were asymptomatic and had a low level of virus replication (<10 copies ml-1). The expression level of cytokines including gamma interferon...
Satou K, Nishiura H.To evaluate the partial effects of vaccination against equine Japanese encephalitis (JE) and characterize other prognostic factors based on previous outbreak records in Japan from 1953 to 1960. Methods: Individual case records, which included demographic information, vaccination history, and clinical information (dates of onset, recovery and death, and symptoms), were investigated. The relations between two outcomes, JE death and symptomatic period, and other variables were examined. Results: Of a total reported 803 cases during the observation period, 453 (56.5%) were diagnosed with either se...
Gardner IA, Wong SJ, Ferraro GL, Balasuriya UB, Hullinger PJ, Wilson WD, Shi PY, MacLachlan NJ.A prospective cohort study was used to estimate the incidence of West Nile virus (WNV) infection in a group of unvaccinated horses (n = 37) in California and compare the effects of natural WNV infection in these unvaccinated horses to a group of co-mingled vaccinated horses (n = 155). Horses initially were vaccinated with either inactivated whole virus (n = 87) or canarypox recombinant (n = 68) WNV vaccines during 2003 or 2004, prior to emergence of WNV in the region. Unvaccinated horses were serologically tested for antibodies to WNV by microsphere immunoassay incorporating recombinant WNV E ...
Couissinier-Paris P.Until 1999 the West Nile virus had been reported only in the "Old world" and particularly in Europe, Africa, Middle East and Asia where it was responsible only for sporadic or size-and-time-limited outbreaks in humans and equines. The sudden and unexpected emergence of WN in New York in 1999, followed by a rapid and huge extension to the whole North America in less than four years, made health authorities aware of the potential of previously forgotten viruses to become a threat to public health. The present review will focus on the epidemiology of West Nile virus in Europe and Africa during th...
Morales MA, Barrandeguy M, Fabbri C, Garcia JB, Vissani A, Trono K, Gutierrez G, Pigretti S, Menchaca H, Garrido N, Taylor N, Fernandez F, Levis S....West Nile virus (WNV) was isolated from the brains of 3 horses that died from encephalitis in February 2006. The horses were from different farms in central Argentina and had not traveled outside the country. This is the first isolation of WNV in South America.
Leblond A, Sandoz A, Lefebvre G, Zeller H, Bicout DJ.Geographic information system and remote sensing technologies were used to identify landscape features associated with risk of West Nile virus transmission as defined by the presence of confirmed horse cases. SPOT-4 images of Camargue area were used to generate a map of landscape categories of epidemic foci and the geographic information system was employed to determine the proportion of landscape components surrounding 10 horse case sites and 17 control sites. The spatio-temporal analysis of the cases outbreak gave the best results for a spatial window of 9 km and a temporal window of 18 days...
Gulati BR, Deepa R, Singh BK, Rao CD.Rotaviruses causing severe diarrhea in foals in two organized farms in northern India, during the period from 2003 to 2005, were characterized by electropherotyping, serotyping, and sequence analysis of the genes encoding the outer capsid proteins. Of 137 specimens, 47 (34.31%) were positive for rotavirus and exhibited at least five different electropherotypes (E), E1 to E5. Strains belonging to different electropherotypes exhibited either a different serotype/genotype specificity or a lack of reactivity to typing monoclonal antibodies (MAbs) used in this study. Strains belonging to E1, E2, an...
Martella V, Elia G, Decaro N, Di Trani L, Lorusso E, Campolo M, Desario C, Parisi A, Cavaliere N, Buonavoglia C.In December 2005, equine influenza virus infection was confirmed as the cause of clinical respiratory disease in vaccinated horses in Apulia, Italy. The infected horses had been vaccinated with a vaccine that contained strains representatives from both the European (A/eq/Suffolk/89) and American (A/eq/Newmarket/1/93) H3N8 influenza virus lineages, and the H7N7 strain A/eq/Praga/56. Genetic characterization of the hemagglutinin (HA) and neuraminidase (NA) genes of the virus from the outbreak, indicated that the isolate (A/eq/Bari/2005) was an H3N8 strain closely related to recent representative...
Morgan D.Although there is no recognized transmission of human arboviral infections in the UK, concerns about the possible spread of West Nile virus (WNV) have precipitated coordinated activities around both surveillance and response. The Department of Health has chaired a UK WNV task force since the end of 2000. This is a multidisciplinary group of senior representatives from Agencies and Government Departments involved in human and animal health, entomology and academic departments. Activities include surveillance for WNV infections in humans, and in dead birds, mosquitoes and horses. All have been n...
Bicout DJ, Carvalho R, Chalvet-Monfray K, Sabatier P.The paper examines the prevalence of equine infectious anemia (EIA) in horse populations in the northern part (comprising 89 cities) of Minas Gerais State, Brazil, from January 2002 to December 2004. Data on 8,981 agar gel immunodiffusion test results from the region were used as input for a statistical and autoregressive analysis model to construct a city-level map of the distribution of EIA prevalence. The following EIA prevalence (P) levels were found: 49 cities with 0 < P < or = 0.5%, 26 with 0.5% < P < or = 1.5%, 10 with 1.5% < P < or = 5%, and 4 with 5% < P < or = 25%.
Wittig MB, Wohlsein P, Hagen RM, Al Dahouk S, Tomaso H, Scholz HC, Nikolaou K, Wernery R, Wernery U, Kinne J, Elschner M, Neubauer H.Since 1990 the number of glanders outbreaks in race, military and pleasure horses in Asia and South America is steadily increasing. Glanders, which is eradicated in Western Europe, Australia and Northern America, is currently considered a re-emerging disease. Consequently, the disease may be introduced into glanders-free regions by subclinical carriers at any time. The causative agent of glanders, Burkholderia (B.) mallei, is highly contagious and leads to chronic disease in horses whereas in donkeys and mules the disease is acute and often fatal. Occurrence of the disease leads to internation...
Dao S, Abdillahi AM, Bougoudogo F, Toure K, Simbe C.The district of Bamako is the political and economical capital city of Mali with 1,800,000 inhabitants. The goal of the present retrospective study was to determine the frequency of animal bites, human and animal rabies on the one hand and to determine the frequency and the nature of mad animals on the other hand from January 2000 to December 2003 (4 years). To achieve this goal, we have analysed registers and documents related to rabies in the department of prevention and fight against diseases, the central veterinary laboratory, and also at the lazaret clinic involved in caring for human rab...
Darghouth MA.Several species of piroplasms of livestock are present in Tunisia; some of them are of high veterinary importance. This paper reviews the species already reported in Tunisia on the basis of clinical observations, parasitological routine diagnostic and serological surveys, as well as those considered as potentially present according to epidemiological argumentations. The genus Theileria includes four species reported in Tunisia: T. annulata, T. buffeli, T. ovis, and T. equi. The ovine malignant theileriosis agent, T. lestoquardi, appears to be absent in Tunisia. Five species belonging to the ge...
Archer DC, Pinchbeck GL, Proudman CJ, Clough HE.Colic is an important cause of mortality and morbidity in domesticated horses yet many questions about this condition remain to be answered. One such question is: does season have an effect on the occurrence of colic? Time-series analysis provides a rigorous statistical approach to this question but until now, to our knowledge, it has not been used in this context. Traditional time-series modelling approaches have limited applicability in the case of relatively rare diseases, such as specific types of equine colic. In this paper we present a modelling approach that respects the discrete nature...
Gardner RB, Hart KA, Stokol T, Divers TJ, Flaminio MJ.A 5-week-old Fell Pony colt was examined for fever, lethargy, and anemia. The colt had been lethargic for 1 week before examination, had continued to nurse, had a temperature of 104°F (40°C), and was treated with ceftiofur (5 mg/kg IM q12h). Approximately 36 hours before examination, the colt developed watery diarrhea. Blood work performed by the referring veterinarian on the day of admission revealed a PCV of 10%.
Gillen A, Catherine Archer D.Epidemiologic studies are essential for the generation of evidence-based, preventive health care strategies. This includes ways to minimize colic risk and assist informed decision making concerning diagnosis, treatment, and likely outcomes. It is important to consider that colic is not a simple "disease" but is a syndrome of abdominal pain that encompasses multiple different disease processes, and which is multifactorial in nature. This review focuses on prevention and diagnosis of colic, including specific forms of colic, communications with owners/carers concerning colic risk and management,...
Zimmerli U, Herholz C, Schwermer H, Hofmann M, Griot C.African horse sickness (AHS) of equines is partly transmitted by the same culicoides species as Bluetongue (BT) disease in even-toed ungulates. Horses normally get seriously sick, with a high case fatality rate. Equine Encephalosis is another, but less-known viral disease of equines, caused by viruses of the same genus as BT and AHS. Like BT of serotype 8 in 2006, both diseases could theoretically be introduced to Europe anytime and spread rapidly then. After the lessons learnt from the most recent bluetongue outbreaks in Europe, the regulations and AHS-contingency plans in force must be updat...
Carroll JF, Schmidtmann ET.The American dog tick, Dermacentor variabilis (Say), was the only ixodid tick found feeding on horses in Montgomery County, Md., from May to August. Average tick burdens were low (less than one tick per horse per week), but >80% of 33 horses examined weekly were exposed to tick feeding during the summer. Of the 98 ticks collected, 78% were attached to the tail and 12% were present in the mane. Host-seeking adult D. variabilis were active on vegetation in pastures from May to early August, with most specimens along hedgerows, woods margins, and horse paths.
Boles CL, Raker CW, Wheat JF.An abnormality of the epiglottis and arytenoepiglottic folds that caused epiglottic entrapment was diagnosed in 21 horses. Until recently, this entrapment was poorly understood. Definitive diagnosis of epiglottic entrapment can be made only by endoscopic examination of the epiglottis, arytenoepiglottic folds, and soft palate to differentiate the abnormality from dorsal displacement of the soft palate. Dorsal displacement of the soft palate is often associated with entrapped epiglottis. Epiglottic deformity, especially hypoplasia, is often associated with the entrapment. The abnormality was det...
Seidl AF, Moraes AS, Silva RA.The impact of three treatment strategies for Trypanosoma evansi control on horse mortality in the Brazilian Pantanal based on four size categories of cattle ranches is explored. The region's 49,000 horses are indispensable to traditional extensive cattle ranching and T. evansi kills horses. About 13% of these horses would be lost, annually, due to T. evansi if no control were undertaken. One preventive and two curative treatment strategies are financially justifiable in the Pantanal. The best available technology for the treatment of T. evansi from a horse mortality perspective is the preventi...
Tannahill VJ, Cardwell JM, Witte TH.Colic is a common and potentially life-threatening condition of horses. Multiple risk factors have been previously identified and it is known that a careful management routine can help reduce colic rates. The British military working horse population represents a unique cohort of horses that are intensively managed with a strict regimen. This retrospective study examined the incidence and mortality rate of colic within this population, as well as the signalment of affected horses, and compared these with the general population. Data for 717 horses over a five-year period (2008-2012) were analy...
Cámara A, Contigiani MS, Medeot SI.A serologic survey of horses for Kairi (KRI) and Cache Valley (CV), two related Bunyaviruses, was conducted simultaneously in Cordoba and Santa Fe provinces, Argentina, during late 1983 and 1984. The prevalence of neutralizing antibodies only for KRI was 13.3% and only for CV was 40.0%; but if the total positive sera for KRI and CV were taken into account, the prevalence reached 48.3 and 75.0%, respectively. The prevalence for CV was higher than for KRI in Cordoba (p less than 0.01), but both were similar in Santa Fe province. The demonstration of seroconversion in horses of the two zones for ...
Nixon J.Equine consultant, Jane Nixon, attended the first equine biosecurity course at the British Racing School in November last year, organised by Whorl Publishing. Here, she reports on some of the issues covered.
Colahan PT, Peyton LC, Connelly MR, Peterson R.Twenty-three isolations of Serratia spp were made from 21 horses at the University of Florida Veterinary Medical Teaching Hospital between Jan 1, 1979 and July 1, 1983. Three Serratia spp were involved in single-organism and mixed infections of various tissues. Eight horses of this group died. All horses that died had massive, mixed, gram-negative infection. The other 13 responded to treatment, including systemic antibiotic therapy. Most of these horses were stressed and under antibiotic therapy prior to the time of culture. Possible nosocomial infection, variable antibiotic sensitivity, and a...
Tedla M, Gebreselassie M.This study was performed with the objective of identifying the proportion of emerging and endemic livestock diseases using cross sectional survey. Results: A total of 285 clinically diseased animals were presented to a veterinary clinic and diagnosed tentatively based on history, clinical sign, and simple laboratory diagnostics and from the study, actinomycosis (15.83%), mastitis (15%), tick infestation (10%), respiratory diseases (9.16%) and gastro intestinal parasitism (9.16%) were confirmed with higher proportion in large animals. Pasteurollosis (38, 31%), contagious ecthyma (12, 10%), tick...
McCluskey BJ, Pelzel-McCluskey AM, Creekmore L, Schiltz J.Vesicular stomatitis is a viral disease primarily affecting horses and cattle when it occurs in the United States. Outbreaks in the southwestern United States occur sporadically, with initial cases typically occurring in Texas, New Mexico, or Arizona and subsequent cases occurring in a northward progression. The viruses causing vesicular stomatitis can be transmitted by direct contact of lesioned animals with other susceptible animals, but transmission is primarily through arthropod vectors. In 2012, an outbreak of vesicular stomatitis in the United States occurred that was caused by Vesicular...