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.
Hao L, Yuan D, Li S, Jia T, Guo L, Hou W, Lu Z, Mo X, Yin J, Yang A, Zheng W, Li R.Theileria species, with a broad geographic distribution, infect a wide range of both domestic and wild animals and are transmitted by ixodid ticks. Currently, there is no comprehensive report regarding the distribution of Theileria spp. in the eastern Tibetan Plateau, especially in Ganze Tibetan autonomous prefecture (153,700 km) and Ngawa Tibetan and Qiang autonomous prefecture (84,242 km) of Sichuan province, China. In this study, we collected blood samples from yaks (n = 144) (Bos grunniens), Tibetan sheep (n = 92), and Tibet horses (n = 142) in Ganze and Ngawa.Theileria sinen...
Alvarez IJ, Fort M, Pasucci J, Moreno F, Gimenez H, Näslund K, Hägglund S, Zohari S, Valarcher JF.Influenza D virus (IDV) is considered a new agent involved in bovine respiratory disease (BRD). Based on seroprevalence studies or isolation from clinical samples, this virus has been detected on several continents and in several animal species, including cattle, pigs, camel, horses, and goats. We used an indirect in-house ELISA to detect anti-IDV antibodies in 165 serum samples from bulls on 116 farms in the province of La Pampa, Argentina. Eighty-five of 116 (73%) farms had at least 1 positive animal, and 112 of 165 (68%) of the analyzed samples were positive. There were no significant diffe...
Onyiche TE, Taioe MO, Ogo NI, Sivakumar T, Biu AA, Mbaya AW, Xuan X, Yokoyama N, Thekisoe O.Babesia caballi and Theileria equi are biological agents responsible for equine piroplasmosis (EP). We conducted a robust and extensive epidemiological study in Nigeria on the prevalence and risk factors of EP. Blood (468, both horses and donkeys) and ticks (201 pools) were screened using polymerase chain reaction (PCR). DNA of equine piroplasms was observed in tick pools with B. caballi amplified in Rhipicephalus evertsi evertsi only [minimum infection rate (MIR) of 7.6%] while T. equi was observed in R. e. evertsi (MIR, 61.6%), Hyalomma dromedarii (MIR, 23.7%) and H. truncatum (MIR, 50.0%). ...
Baigazinov ZА, Lukashenko SN, Panitsky АV, Kadyrova NZ, Karatayev SS, Mamyrbayeva АS, Baigazy SА, Bazarbaeva АМ, Kabdyrakova AB....Horses are important food sources in several countries however, data on their radionuclide uptake is less available than for many other farm animals. Information on the transfer of artificial radioisotopes from the environment to the food supply is necessary for internal dose assessment and assuring the safety of the population relying on this food source. This study provides data for a less studied farm animal and, in the case of Am and Pu, relatively poorly studied radionuclides with respect to transfer to animal products. The transfer parameters for Pu, Am, Cs and Sr to the organs of 1-year...
Malekinejad H, Fink-Gremmels J.Molds and mycotoxins are contaminants of animal feed causing spoilage and clinical intoxication. Animal exposure to mycotoxins reflects diet composition with major differences occurring between animals kept predominantly of pastures, i.e. ruminants and horses, and those consuming formulated feed like pigs and poultry. Mixed feeds are composed of several ingredients, often sourced from different continents. Subsequently, practitioners may confront endemic diseases and signs of toxin exposure related to toxins imported accidentally with contaminated feed materials from other countries and contin...
Zhao A, Zhang Y, Wang W, Jing B, Xing J, Tao D, Zhao W, Qi M.Enterocytozoon bieneusi, a zoonotic pathogen, has the potential to infect both immunocompromised and immunocompetent humans. It is found in large number of animals; however, not much is known regarding its prevalence in equine animals, particularly donkeys. This is the first molecular epidemiological evaluation of E. bieneusi in 178 free-ranging donkeys from five countrysides; and 502 farmed donkeys from 18 farms in 12 cities of Xinjiang, China by Nested PCR. Results: E. bieneusi was detected in 2.5% (17/680) donkeys, with 2.6% (13/502) in farmed and 2.2% (4/178) in free-ranging ones. Sequence...
Torquato RBC, Iamamoto K, Fernandes ER, Achkar S, Silva SR, Katz ISS, Guedes F.Laboratory diagnosis of rabies in equines is essential for distinguishing the disease from other sources of encephalitis. Diagnosis by conventional techniques such as a direct fluorescent antibody test (dFAT) or viral isolation in mice or cell culture can be difficult, and the application of molecular biological methods may be necessary. We performed an indirect rapid immunohistochemistry test (iRIT) for the detection of the rabies virus (RABV) antigen in the central nervous system (CNS) of equines and compared the results with those of other diagnostic techniques. We reviewed result records f...
Lin Y, Wang XF, Wang Y, Du C, Ren H, Liu C, Zhu D, Chen J, Na L, Liu D, Yang Z, Wang X.Lentiviruses harbour high genetic variability for efficient evasion from host immunity. An attenuated equine infectious anaemia (EIA) vaccine was developed decades ago in China and presented remarkably robust protection against EIA. The vaccine was recently proven to have high genomic diversity, particular in . However, how and to what extent the high diversity relates to immune protection remains unclear. In this study, we compared immune protections and responses of three groups of horses stimulated by the high-diversity vaccine EIAV_HD, a single molecular clone of the vaccine EIAV_LD with ...
Shah MH, Ijaz M, Ahmed A, Aziz MU, Ghaffar A, Ghauri HN, Naveed M.Theileriosis is an important disease of economic significance which badly affects the equine husbandry of developing countries. The present study was planned to investigate the molecular prevalence of theileriosis, associated risk factors, and alterations in hematological parameters of donkeys and mules from district Mianwali, Punjab, Pakistan. Blood samples from 150 equids (n = 75 donkeys; n = 75 mules) were examined microscopically, and the genomic DNA from each sample was processed for the amplification of the 18S rRNA gene of Theileria. The polymerase chain reaction confirmed isolates we...
Annand EJ, Reid PA, Johnson J, Gilbert GL, Taylor M, Walsh M, Ward MP, Wilson A, Degeling C.Hendra virus (HeV) is endemic in Australian flying foxes, posing a threat to equine and human health. Equine vaccination remains the most effective risk mitigation strategy. Many horses remain unvaccinated - even in higher-risk regions. Debate surrounding the vaccine's use is characterised by conflicting perspectives, misunderstanding and mistrust. Private veterinary practitioners are critical to early identification of public health risk through recognition, sampling and management of suspect-equine-HeV-cases. However, managing such cases can be burdensome, with some veterinarians opting not ...
Baumann S, Gurtner C, Marti H, Borel N.Species of genus are important pathogens of animals, with a worldwide distribution and broad host range. Some species, such as , also pose a zoonotic disease risk. Abortion is one of the many diseases that has been associated with chlamydial infections in animals, with most attention focused on the economic impacts to sheep production. The role of chlamydia in equine abortions is unknown. Using the family-specific 23S ribosomal RNA (rRNA) real-time PCR, we tested 169 formalin-fixed, paraffin-embedded fetal membrane samples from 162 equine abortion cases collected between 2000 and 2018 in Swi...
Dik B, Ceylan O, Ceylan C, Tekindal MA, Semassel A, Sönmez G, Derinbay Ekici Ö.Approximately 250 feral horses [ (Linnaeus, 1758)] living on Karadağ Mountain near Karaman City were caught by Kazakh horse herdsmen with permission of the Turkish Ministry of Agriculture and Forestry and brought to a farm in Karkın village in Konya Province, 70 km from Karadağ, in November, 2017. This study was carried out to determine the presence of ectoparasites infesting a subsample of 36 feral horses. The horses were visually inspected, and then their bodies were checked by hand for ectoparasites. Thirty-five (97.2%) were infested with at least one of five species of ectoparasites: ...
Duran MC, Dumrath CAC, Bartmann CP, Medina Torres CE, Moschos A, Goehring LS.Serum amyloid A (SAA) is a sensitive acute-phase response (APR) marker in equids. Prominent APRs with elevations of SAA concentrations ([SAA]) have been reported after vaccination. The authors hypothesized that vaccination with an inactivated EHV-1/-4 vaccine would cause increase in [SAA] and antibody responses and that higher [SAA] would be positively correlated with the antibody titer in both equids. Twelve Haflinger horses and 12 mules were included in this longitudinal prospective study. All horses and mules were vaccinated with a commercially available EHV-1/-4 vaccine. Blood was sampled ...
Abu-Halaweh M, Abo-Shehada MN, Khalil R.A cross-sectional study was carried out on a sample of 379 horses to determine the seroprevalence of Neospora spp. in Jordan using the indirect fluorescent antibody test. Five variables, namely locality (n=10), climatic zone (n=4), age group (n=3), gender, and breed were tested as risk factors for Neospora-immunoglobulin (Ig)G seropositivity at four cutoff titers (1:50, 1:200, 1:400, and 1:800) using univariate and multivariate logistic regression analyses. A total of 122 (32%; 95% CI: 28, 37) sera samples had anti-Neospora-IgG at a cutoff titer of 1:50. Increased Neospora-IgG seropositivity w...
Tenzin T, Lhamo K, Rai PB, Tshering D, Jamtsho P, Namgyal J, Wangdi T, Letho S, Rai T, Jamtsho S, Dorji C, Rinchen S, Lungten L, Wangmo K, Lungten L....Rabies kills approximately 59,000 people each year worldwide. Rapid and accurate diagnosis of rabies is important for instituting rapid containment measures and for advising the exposed people for postexposure treatment. The application of a rapid diagnostic tests in the field can greatly enhance disease surveillance and diagnostic activities, especially in resource poor settings. In this study, a total of 179 brain tissue samples collected from different rabies suspect animal species (113 dogs, 50 cattle, 10 cats, 3 goats, 2 horses, and 1 bear) were selected and tested using both rapid immuno...
Henker LC, Lorenzett MP, Keller A, Siqueira FM, Driemeier D, Pavarini SP.Pantoea agglomerans, family Enterobacteriaceae, is a Gram-negative bacterium that may be isolated from soil and from plants. This bacterium has been associated with disease in plants, humans, and rarely in domestic animal species. We describe here a case of fibrinonecrotic placentitis and equine abortion associated with P. agglomerans infection in southern Brazil. A fetus with 10 months of gestation and its placenta were evaluated. Gross lesions were observed in the cervical star extending to the body of the chorioallantois and consisted of a focally extensive, transmural, severely thickened...
Wang Y, Zhang LP, Li J, Li DD, Zhang Q, Li C.The aim of this study was to determine the seroprevalence of Babesia caballi and Theileria equi in horses imported into Shanghai port. Between 2018 and 2019, 344 horse sera samples were collected and tested for B. caballi and T. equi, using commercially available kits. Only one B. caballi seropositive sample was detected. To the best of our knowledge, this is the first report of a B. caballi seropositive in imported horses at Shanghai port, which reflects the importance of monitoring piroplasmosis seroprevalence in imported horses.
Studzińska MB, Sallé G, Roczeń-Karczmarz M, Szczepaniak K, Demkowska-Kutrzepa M, Tomczuk K.Parascaris spp. are major gastro-intestinal nematodes that infect foals and can lead to respiratory symptoms, poor growth, and in some cases obstruction of the small intestine and death. Ivermectin resistance has been reported for Parascaris spp. in many countries. In Poland, the knowledge of the level of resistance against ivermectin in Parascaris spp. is limited. The aim of this study was to examine the efficacy of ivermectin against Parascaris spp. in foals from south-eastern Poland. Foals (n = 225 = reared in 7 stud farms) were treated orally with ivermectin paste. Faecal samples w...
Porcellato I, Modesto P, Cappelli K, Varello K, Peletto S, Brachelente C, Martini I, Mechelli L, Ferrari A, Ghelardi A, Razzuoli E.In horses, squamous cell carcinomas (SCCs) are the most common malignant tumors developing on non-pigmented skin, muco-cutaneous areas, like external genitalia, and, less frequently, in the stomach. Growing evidence suggests Equus caballus papillomavirus type 2 (EcPV2) as causative agent of genital SCCs. Our case report describes a 20-year-old, female, mixed-breed pony with co-occurring vulvar papilloma and in situ carcinoma and gastric SCC. Both lesions were positive for the same EcPV2, as confirmed by DNA sequencing. E6 mRNA expression was observed both in vulvar lesions and gastric SCC, whi...
Nemoto M, Niwa H, Kida H, Higuchi T, Orita Y, Sato S, Bannai H, Tsujimura K, Ohta M.A rare genotype G13P[18] group A rotavirus (RVA/Horse-tc/JPN/MK9/2019/G13P[18]) was isolated from a diarrhoeic foal for the first time in 28 years. The genotype constellation of the virus was assigned to G13-P[18]-I6-R9-C9-M6-A6-N9-T12-E14-H11 and was the same as that of the first isolated strain, RVA/Horse-tc/GBR/L338/1991/G13P[18]. Phylogenetic analysis suggests that the virus is related to RVA/Horse-tc/GBR/L338/1991/G13P[18] and is distant from typical equine rotaviruses of the G3P[12] and G14P[12] genotypes.
Babesia caballi and Theileria equi are widely recognized as causative agents of equine pirolasmosis (EP), an acute, sub-acute, and chronic disease of equines, with relevant economic impact on horse trade worldwide. Although several studies on EP prevalence from central Italy have been published, data on ticks responsible for its transmission are still lacking. In this study, we identified a potential competent vector, investigating main features of its ecology together with EP infection rates. A two-year sampling of questing ticks was carried out for the first time in Italy in an area known fo...
Solís-Hernández D, Saucedo-Gutiérrez KL, Meza-Lucas A, Gómez-de-Anda FR, Medina-Lerena MS, García-Rodea R, Corona-Souza MT, Pérez-Ramírez MÁ....This work aimed to investigate the prevalence of Trichinella infection in horses (Equus ferus caballus) handled by rural slaughterhouses across five distinctive socioeconomic regions in Mexico. Serum samples were obtained by non-probabilistic convenience sampling in the Eastern, Southern Central and Western regions (100 samples of each). Additionally, muscle tissue samples were collected from the East (n=45), Southeastern (n=88), Southern Central (n=39) and Southwestern (n=11) regions. Antibodies were determined by Western blot and the muscle tissue was examined by artificial digestion. A glob...
Camino E, Schmid S, Weber F, Pozo P, de Juan L, König M, Cruz-Lopez F.Tick-borne encephalitis virus (TBEV) and louping-ill virus (LIV) are two closely related zoonotic flaviviruses leading to neurological diseases and belonging to the tick-borne encephalitis (TBE) serocomplex. Both viruses are transmitted by the same ixodid tick vector, Ixodes ricinus. Due to global warming affecting vector biology and pathogen transmission, the viruses pose an emerging threat for public health in Europe and Asia. These flaviviruses share some hosts, like sheep, goats and humans, although the main hosts for LIV and TBEV are sheep and small rodents, respectively. Whereas LIV has ...
Li Y, Wen X, Li M, Moumouni PFA, Galon EM, Guo Q, Rizk MA, Liu M, Li J, Ji S, Tumwebaze MA, Byamukama B, Chahan B, Xuan X.Ticks carry and transmit a wide range of pathogens (bacteria, viruses, and protozoa) that are of importance to humans and animals globally. However, information about the tick-borne pathogens harbored by ticks in the Xinjiang Uygur Autonomous Region (XUAR), northwestern China, is scarce. This study investigated the occurrence of tick species of domestic animals and tick-borne pathogens by using morphological molecular identification and sequence analysis in Turpan, Qitai, Altay, Hejing, Nileke, and Zhaosu counties (XUAR). A total of 5822 adult ticks (females and males) from 12 tick species wer...
León B, Käsbohrer A, Hutter SE, Baldi M, Firth CL, Romero-Zúñiga JJ, Jiménez C.Eastern equine encephalitis and Venezuelan equine encephalitis are endemic neglected tropical diseases in the Americas, causing encephalitis in both horses and humans. In 2013, a cross-sectional study was performed in 243 horses located in the highlands and lowlands throughout Costa Rica. Serum samples were analyzed with an IgG ELISA and confirmed by the plaque-reduction neutralization test (PRNT80). Venezuelan equine encephalitis virus (VEEV) and Eastern equine encephalitis virus (EEEV) overall seroprevalences by the PRNT80 were 36% (95% confidence interval [CI]: 29.9-42.5; 78/217 horses) and...
EHV1 and EHV4 are the most important herpesviruses in horses. Repeated cases of abortion in mares regularly vaccinated, prompted us to investigate the immune response after vaccination with the same inactivated vaccine, but with three different protocols. Eighteen mares were chosen and randomly divided in three study groups (G-G-G) and a control group (Ctrl). For serologic and PCR investigations nasal swabs, sera and blood were collected. The protocol used in G (4 doses) increased the titer recorded by ELISA and seroneutralization (SN). Poor agreement and no correlation were observed in titer ...
Molini U, Zaccaria G, Kandiwa E, Mushonga B, Khaiseb S, Ntahonshikira C, Chiwome B, Baines I, Madzingira O, Savini G, D'Alterio N.African horse sickness (AHS) is a non-contagious viral disease of horses and other equids caused by an arbovirus belonging to the Reoviridae family and genus Orbivirus. AHS is an endemic disease that is responsible for the death of a high number of horses every year in Namibia. At present, there is no information on the prevalence and distribution of AHS virus (AHSV) serotypes in the different regions of Namibia. Therefore, this survey aimed to fill this knowledge gap by investigating the AHSV seroprevalence in Namibian donkeys. Methods: A total of 260 blood samples (20 samples for each region...
El-Hage CM, Bamford NJ, Gilkerson JR, Lynch SE.Ross River virus (RRV) is a mosquito-borne arbovirus of the genus Alphavirus that causes disease in humans and horses in Australia. A temporal association of RRV infection in horses with clinical signs including pyrexia, malaise, and polyarthralgia has been reported, along with reduced athletic performance, often for extended periods. Despite these reports, disease due to RRV remains somewhat controversial as experimental infection of horses has resulted in obvious viraemia yet minimal signs of clinical disease. The relatively high viraemia demonstrated by horses infected with RRV has led to s...
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...
Díaz-Sánchez AA, Pires MS, Estrada CY, Cañizares EV, Del Castillo Domínguez SL, Cabezas-Cruz A, Rivero EL, da Fonseca AH, Massard CL....Equine piroplasmosis is a disease of Equidae, including horses, donkeys, mules, and zebras, caused by either Theileria equi or Babesia caballi. This disease represents a serious problem for the horse industry and its control is critical for the international trade of horses. The objective of the present study was to detect B. caballi and T. equi infections in horses reared in western Cuba. Blood samples from 100 horses were tested for the presence of piroplasms by using Giemsa-stained blood smears and nested PCR (nPCR) assays targeting merozoite antigen genes of B. caballi (bc48) and T. equi (...
Jaqueth AL, Iwaniuk ME, Burk AO.It has been estimated in the United States and abroad that 20%-51% of the equine population suffers from over-conditioning or obesity. The objective of this study was to evaluate the prevalence of over-conditioning in the equine population in Maryland, to characterize weight control measures used, and to ascertain how control measures impact the operation. Over-conditioning was defined as a body condition score of 4 or 5 on a 5-point scale. All licensed horse operators in Maryland were invited to participate in an online survey. A total of 93 farm operators completed the survey with 238 ponies...
Gozalo-Marcilla M, Bettschart-Wolfensberger R, Johnston M, Taylor PM, Redondo JI.It is almost 20 years since the largest observational, multicentre study evaluating the risks of mortality associated with general anaesthesia in horses. We proposed an internet-based method to collect data (cleaned and analysed with R) in a multicentre, cohort, observational, analytical, longitudinal and prospective study to evaluate peri-operative equine mortality. The objective was to report the usefulness of the method, illustrated with the preliminary data, including outcomes for horses seven days after undergoing general anaesthesia and certain procedures using standing sedation. Within ...
Diallo AA, Souley MM, Issa Ibrahim A, Alassane A, Issa R, Gagara H, Yaou B, Issiakou A, Diop M, Ba Diouf RO, Lo FT, Lo MM, Bakhoum T, Sylla M....Since November 2018, several countries in West and Central Africa have reported mortalities in donkeys and horses. Specifically, more than 66,000 horses and donkeys have succumbed to disease in Burkina Faso, Chad, Cameroon, The Gambia, Ghana, Mali, Niger, Nigeria, and Senegal. Strangles caused by Streptococcus equi subsp equi, African Horse Sickness (AHS) virus, and Equine influenza virus (EIV) were all suspected as potential causative agents. This study reports the identification of EIV in field samples collected in Niger and Senegal. Phylogenetic analysis of the hemagglutinin and neuraminida...
Teymournejad O, Lin M, Bekebrede H, Kamr A, Toribio RE, Arroyo LG, Baird JD, Rikihisa Y.Potomac horse fever (PHF), a severe and frequently fatal febrile diarrheal disease, has been known to be caused only by , an endosymbiont of digenean trematodes. Here, we report the cell culture isolation of a new species found in two locations in eastern Ontario, Canada, in 2016 and 2017 (in addition to 10 variable strains of ) from PCR-negative horses with clinical signs of PHF. Gene sequences of 16S rRNA and the major surface antigen P51 of this new species were distinct from those of all previously characterized strains and species, except for those from an uncharacterized species cu...
Niczyporuk JS, Samorek-Salamonowicz E, Lecollinet S, Pancewicz SA, Kozdruń W, Czekaj H.Serum samples of 474 wild birds, 378 horses, and 42 humans with meningitis and lymphocytic meningitis were collected between 2010 and 2014 from different areas of Poland. West Nile virus (WNV) antibodies were detected using competition enzyme linked immunosorbent assays: ELISA-1 ID Screen West Nile Competition, IDvet, ELISA-2 ID Screen West Nile IgM Capture, and ELISA-3 Ingezim West Nile Compac. The antibodies were found in 63 (13.29%) out of 474 wild bird serum samples and in one (0.26%) out of 378 horse serum samples. Fourteen (33.33%) out of 42 sera from patients were positive against WNV a...
Corbin LJ, Kranis A, Blott SC, Swinburne JE, Vaudin M, Bishop SC, Woolliams JA.Despite the dramatic reduction in the cost of high-density genotyping that has occurred over the last decade, it remains one of the limiting factors for obtaining the large datasets required for genomic studies of disease in the horse. In this study, we investigated the potential for low-density genotyping and subsequent imputation to address this problem. Results: Using the haplotype phasing and imputation program, BEAGLE, it is possible to impute genotypes from low- to high-density (50K) in the Thoroughbred horse with reasonable to high accuracy. Analysis of the sources of variation in imput...
Burton AJ, Nydam DV, Dearen TK, Mitchell K, Bowman DD, Xiao L.To date, little is known about the prevalence, genotypes and zoonotic potential of Cryptosporidium spp. affecting horses, especially in North America. A cross-sectional study was conducted in New York, USA between February 25th and May 1st 2009. Fecal samples were collected from three hundred and forty nine 1-10-week-old foals and their dams on 14 different broodmare farms. All fecal samples were screened for Cryptosporidium spp. using a direct immunofluorescence assay (DFA). DNA extraction and PCR-RFLP analysis of the small-subunit (SSU) rRNA gene were performed on all the foal samples. PCR-p...
Vallance SA, Entwistle RC, Hitchens PL, Gardner IA, Stover SM.Identification of exercise history patterns that are related to catastrophic scapular fracture will facilitate prevention of racehorse fatalities. Objective: To determine if exercise patterns are associated with scapular fracture in Thoroughbred (TB) and Quarter Horse (QH) racehorses. Methods: High-speed exercise histories for 65 TB and 26 QH racehorses that had a complete scapular fracture (cases) and 2 matched control racehorses were retrospectively studied. Exercise variables were created from lifetime race and official timed workout reports. Associations between exercise variables and scap...
Johnson AL, McAdams SC, Whitlock RH.The objective of the current retrospective study was to describe naturally occurring type A botulism in horses in the United States. In the past 10 years, the Botulism Laboratory at the University of Pennsylvania's School of Veterinary Medicine has identified 3 isolated cases and 8 outbreaks of type A botulism in horses via samples positive for Clostridium botulinum type A toxin or spores using the mouse bioassay test. Additional information was obtained by review of submission forms and by telephone or email interviews. Almost all type A cases and outbreaks occurred in the western United Stat...
Clausen PH, Chuluun S, Sodnomdarjaa R, Greiner M, Noeckler K, Staak C, Zessin KH, Schein E.From May to July 2000, a cross-sectional study was conducted to estimate the prevalence of Trypanosoma equiperdum in the horse population of the central province (Tuv aimag) of Mongolia. On average, four herds were selected from each of the 29 aimag subdivisions (119 herds). From each herd, 10 horses were sampled in proportion to sex and age categories in the respective herds (1190 horses). Sera from 1122 horses were analysed for T. equiperdum antibodies using two serological assays, the complement fixation test (CFT) and the enzyme-linked immunosorbent assay (ELISA). The crude estimate of the...
Fougerolle S, Fortier C, Legrand L, Jourdan M, Marcillaud-Pitel C, Pronost S, Paillot R.Every year, several epizooties of equine influenza (EI) are reported worldwide. However, no EI case has been identified in France between 2015 and late 2018, despite an effective field surveillance of the pathogen and the disease. Vaccination against equine influenza virus (EIV) remains to this day one of the most effective methods to prevent or limit EI outbreaks and the lack of detection of the pathogen could be linked to vaccination coverage. The aim of this study was to evaluate EI immunity and vaccine coverage in France through a large-scale serological study. A total of 3004 archived sur...
Herd RP.Seasonal rises in mean faecal egg output were observed in grazing ponies in spring (578 eggs per gram) and in summer (930 epg) on 30 April and 2 September, respectively, in untreated ponies. Pasture infectivity reached a peak of 18,486 third stage larvae (L3)/kg on 17 September, two weeks after peak egg counts, coincidental with abundant September rainfall (103.0 mm). Differentiation of infective larvae from pasture showed the cyathostomes (small strongyles) to be predominant, but Trichostrongylus axei assumed major importance from late August to October. The large strongyles were rarely detec...
Morley PS, Bromberek JL, Saulez MN, Hinchcliff KW, Guthrie AJ.Exercise-induced pulmonary haemorrhage (EIPH) occurs commonly in Thoroughbred racehorses worldwide. While EIPH is believed to be an important cause of impaired performance in these horses, there is limited evidence from sufficiently powered studies to evaluate this association. Objective: To evaluate whether EIPH is associated with finishing position, distance finished behind race winners and differences in race earning among Thoroughbred horses racing in South Africa. Methods: Prospective cross-sectional study. Methods: One thousand Thoroughbred horses racing in South Africa were enrolled pri...
Balasuriya UB, Crossley BM, Timoney PJ.Equid herpesvirus 1 (EHV-1) is one of the most economically important equine viral pathogens. Its clinical manifestations in horses vary from acute upper respiratory tract disease, abortion, or neonatal death, to neurological disease termed equine herpesviral myeloencephalopathy, which may lead to paralysis and a fatal outcome. Successful identification of EHV-1 infection in horses depends on a variety of factors such as suitable case selection with emphasis on timing of sample collection, selection of appropriate sample(s) based on the clinical manifestations, application of relevant diagnost...
Hinchcliff KW, Morley PS, Jackson MA, Brown JA, Dredge AF, O'Callaghan PA, McCaffrey JP, Slocombe RF, Clarke AF.Risk factors for occult exercise-induced pulmonary haemorrhage (EIPH) are poorly defined or quantified. Objective: To investigate the importance of putative risk factors for EIPH amongst Thoroughbred racehorses in Australia. Methods: Tracheobronchoscopy was used to determine EIPH status of 744 Thoroughbred racehorses after flat racing in Melbourne, Australia. Horses were identified for study before racing, and over 50% of horses racing during the study period were examined. Statistical analysis included use of bivariate and multivariate logistic regression analysis to account for simultaneous ...
Letson GW, Bailey RE, Pearson J, Tsai TF.An Eastern equine encephalitis (EEE) outbreak in 1989 led to nine human and 196 equine cases, chiefly in coastal Atlantic and Gulf Coast counties. In the past two decades, EEE age-specific incidence and mortality rates have declined compared with earlier years. Analysis of rainfall patterns in areas where human EEE cases occurred between 1983 and 1989 revealed an association between occurrence of human cases and excess rainfall. The association was stronger with data from local weather stations than from statewide rainfall averages and the predictive models were best when applied to northern s...
Cook SJ, Cook RF, Montelaro RC, Issel CJ.Most in vivo studies with equine infectious anemia virus (EIAV) have been performed in horses and ponies (Equus caballus) with little published information available detailing the clinical responses of donkeys (Equus asinus) to infection with this virus. Consequently, donkeys were inoculated with two strains of EIAV (EIAV(PV) and EIAV(WY)) which have been documented to produce disease in E. caballus. Four ponies, 561, 562, 564 and 567 and two donkeys, 3 and 5 were infected with EIAV(PV) and one horse (94-10) and one donkey (4) were infected with EIAV(WY). Although the horse and ponies all expe...
Li F, Drummer HE, Ficorilli N, Studdert MJ, Crabb BS.Equine rhinovirus 1 (ERhV1) is a recognized cause of acute febrile respiratory disease in horse, although the virus is rarely isolated from such animals, despite seroprevalence rates as high as 50% in some horse populations. Recently, ERhV1 has been shown to be most closely related to foot-and-mouth disease virus, raising questions as to its disease associations in horses. We report that ERhV1 infection was the likely cause of two separate outbreaks of severe febrile respiratory disease which involved more than 20 horses. Attempts to isolate ErhV1 from nasopharyngeal swabs by conventional cell...
Dennis SJ, O'Kennedy MM, Rutkowska D, Tsekoa T, Lourens CW, Hitzeroth II, Meyers AE, Rybicki EP.African horse sickness (AHS) is caused by multiple serotypes of the dsRNA AHSV and is a major scourge of domestic equids in Africa. While there are well established commercial live attenuated vaccines produced in South Africa, risks associated with these have encouraged attempts to develop new and safer recombinant vaccines. Previously, we reported on the immunogenicity of a plant-produced AHS serotype 5 virus-like particle (VLP) vaccine, which stimulated high titres of AHS serotype 5-specific neutralizing antibodies in guinea pigs. Here, we report a similar response to the vaccine in horses. ...
Madigan JE, Pusterla N, Johnson E, Chae JS, Pusterla JB, Derock E, Lawler SP.Ehrlichia risticii, the agent of Potomac horse fever (PHF), has been recently detected in trematode stages found in snail secretions and in aquatic insects. Based on these findings, horses could conceivably be exposed to E. risticii by skin penetration with infected cercariae, by ingestion of infected cercariae in water or via metacercariae in a second intermediate host, such as an aquatic insect. In order to test this hypothesis, horses were challenged with infectious snail secretions and aquatic insects collected from a PHF endemic region in northern California. Two horses stood with their f...
Azmi K, Tirosh-Levy S, Manasrah M, Mizrahi R, Nasereddin A, Al-Jawabreh A, Ereqat S, Abdeen Z, Lustig Y, Gelman B, Schvartz G, Steinman A.West Nile virus (WNV) epidemiological situation in Israel and Palestine, due to their unique location, draws attention following to the global spread of West Nile fever (WNF). Although much information is available from Israel on clinical cases and prevalence of WNV, clinical cases are rarely reported in Palestine, and prevalence is not known. The objectives of this study were to determine WNV seroprevalence in various domestic animals in Palestine and to reevaluate current seroprevalence, force of infection, and risk factors for WNV exposure in horses in Israel. Sera samples were collected fr...
McGuire TC, Crawford TB, Hallowell AL, Macomber LE.Failure in colostral immunoglobulin G (IgG) transfer was found in 9 of 87 Thoroughbred foals. Seven (78%) of these 9 foals acquired infections requiring therapy. Twelve of the foals had partial failure in colostral IgG transfer, and 3 of these had infections requiring therapy. The remaining 66 foals had normal transfer of colostral IgG, and only 2 had detectable infections. The failure of colostral IgG transfer was attributable to nursing problems in only one case. When presuckle postpartum colostrum was collected, 2 of 4 failures of colostral IgG transfer and 4 of 6 partial failures of colost...
Carslake HB, Pinchbeck GL, McGowan CM.The epidemiology of equine metabolic syndrome (EMS) is poorly described. Objective: To estimate the prevalence of EMS in native UK ponies and cobs in England and Wales and identify associated risk factors. Methods: Cross-sectional study. Methods: Breeders registered with UK native pony breed societies and registered riding schools and livery yards within a set radius were invited to participate. All native UK ponies and cobs aged 3-14 years and not diagnosed or being treated for conditions likely to affect insulin regulation at participating premises were eligible. Animals underwent a clinica...
Tsunemitsu H, Jiang B, Saif LJ.Enzyme-linked immunosorbent assays (ELISAs) were developed to detect group (gp) C rotavirus antigens and antibodies. Both assays were confirmed to be specific for gp C rotavirus by using serogroup A, B, and C rotaviruses; hyperimmune antisera to these serogroups of rotaviruses; and paired serum specimens from animals infected with gp C rotaviruses. The ELISA for antigen detection reacted not only with porcine gp C rotaviruses but also with human and bovine gp C rotaviruses. Following experimental challenge of gnotobiotic pigs with porcine gp C rotavirus, the virus was found by ELISA in all dia...
Chapman PS, Green C, Main JP, Taylor PM, Cunningham FM, Cook AJ, Marr CM.A total of 1235 tracheal aspirates taken from 724 thoroughbreds in race training, aged from two to 10 years, were examined cytologically and bacteriologically. An inflammation scoring system on a scale of 0 to 9 was devised to allow the severity of lower airway disease to be assessed from the cytological results. The inflammation scores were closely related to the isolation of bacteria (P<0.001), and the most common bacterial isolates were Streptococcus zooepidemicus, Streptococcus pneumoniae and Pasteurella/Actinobacillus-like species. Lower airway disease was less common in older horses (...
Anderson TM, McIlwraith CW, Douay P.The relationship of conformation to future potential injury is a standard approach in practise but, at present, is largely based on subjective observations. Objective: To measure conformation in 3-year-old Thoroughbreds and objectively test its relationship with the occurrence of musculoskeletal problems. Methods: Conformation measurements were taken from photographs using specific reference points marked on the horses and processed on the computer. Clinical observations were recorded for each horse on a regular basis. Stepwise (forward) logistic regression analysis was performed to investigat...
Westbury HA.The author provides an account of the discovery of a previously undescribed disease of horses and a description of the studies involved in determining the aetiology of the disease. The causative virus, now named Hendra virus (HeV), is the reference virus for a proposed new genus within the virus family Paramyxoviridae. The virus is a lethal zoonotic agent able to cause natural disease in humans and horses and experimentally induced disease in cats, guinea-pigs and mice. The virus also naturally infects species of the family Megachiroptera, mainly subclinically, and such animals are the natural...
Chevalier V, Lancelot R, Diaité A, Mondet B, Sall B, De Lamballerie X.The Ferlo area (north-central Senegal) is characterized by a system of temporary ponds favorable to arboviruses among which West Nile fever (WNF) was already identified. During the rainy season in 2003, a serological study was undertaken on horses to assess the activity of the WNF virus (WNFV) in Barkedji (Ferlo). The observed serological prevalence rate was 78.3% for neutralizing antibodies, with a 95% confidence interval (CI) of [64.0, 92.7]. This prevalence rate significantly increased with age (P = 10(-5)). This study confirmed that WNF was endemic in the Ferlo. The transmission risks depe...
