The study of diseases in horses encompasses a wide range of conditions affecting equine health, including infectious diseases, metabolic disorders, and genetic abnormalities. These diseases can impact various systems within the horse, such as respiratory, gastrointestinal, and musculoskeletal systems, and can lead to significant health challenges. Research in this area focuses on understanding the pathophysiology, diagnosis, prevention, and treatment of equine diseases. Common diseases studied include equine influenza, equine herpesvirus, and laminitis. This page provides access to peer-reviewed research studies and scholarly articles that explore the etiology, clinical presentation, and management strategies of diseases in horses, contributing to the advancement of equine veterinary medicine.
Ireland JL, McGowan CM.Research demonstrating insulin's causal role in endocrinopathic laminitis has greatly advanced understanding of equine laminitis. However, the degree to which this knowledge has been translated into clinical practice has not been assessed. This two-part study aimed to investigate veterinary surgeons' current diagnostic approach to laminitis, whether this had changed over time, and the impact of diagnosing an endocrinopathy on laminitis case management and outcome. Two cross-sectional online surveys of equine veterinary surgeons working within the UK were undertaken. The first study population ...
Townsend KS, Johnson PJ, LaCarrubba AM, Martin LM, Ericsson AC.Bacteremia resulting from dental surgery is increasingly recognized as a health risk, especially in older and immunocompromised patients. Dentistry-associated bacteremia can lead to remote infections, as exemplified by valvular endocarditis. Emerging evidence points to a novel role played by oral cavity commensals in the pathogenesis of diabetes, respiratory disease, cardiovascular disease, and adverse pregnancy outcomes. Whether dental extraction, a commonly undertaken procedure in old horses, causes bacteremia has not been reported extensively. In a prospective clinical study using next gene...
Nemoto M, Matsumura T.This review briefly describes the virus classification, clinical signs, epidemiology, diagnosis, disinfection, and vaccines related equine group A rotavirus (RVA) infection. Equine RVA is one of the most important pathogens causing diarrhoea in foals. The main transmission route is faecal-oral, and the clinical signs are diarrhoea, fever, lethargy, and anorexia (decreased suckling). Some human RVA rapid antigen detection kits based on the principles of the immunochromatographic assay are useful for the diagnosis of equine RVA infection. The kits are used in daily clinical practice because of t...
Scilimati N, Pepe M, Pressanto MC, Angeli G, Beccati F.A 4-month-old Thoroughbred filly was referred for evaluation of severe left forelimb lameness of 24 hours duration. Radiographic projections of the shoulder revealed mild irregularity and sclerosis of the proximal humeral apophysis. Ultrasonographic examination showed a moderate increase in the amount of anechogenic synovial fluid within the intertubercular bursa and scapulohumeral joint, and irregularity of the ossifying bone surface of the intermediate tubercle of the humerus. Computed tomographic (CT) examination revealed a circular hypoattenuating area at the level of the proximal apophysi...
Hifumi T, Tanaka T, Hernandez EP, Akioka K, Yamada K, Imamura Y, Hatai H, Miyoshi N.Histopathological and genetic examinations were conducted on grayish-white solid hepatic nodules in 150 horses imported from Canada, in order to investigate larval Echinococcus multilocularis infection. Ten of the 150 horses (6.7%) were diagnosed with alveolar hydatid disease. The sequences of the mitochondrial cytochrome b genes obtained from all 10 polymerase chain reaction positive samples had 99 to 100% identity with the European haplotype E1 of E. multilocularis. Therefore, we concluded that the infections likely originated in Canada. Relation entre les nodules hépatiques solides blanc-g...
Isola M, Piccinotti C, Magro M, Fasolato L, Vianello F, Menandro ML, Memarian P, Rossi M, Falomo ME.The presence of bacteria of various origins on horse hoofs enables the onset of infections following trauma or even post-surgical wounds. Thus, the analysis of new antibacterial substances is of fundamental importance. In this study, the antibacterial efficacy of Iron Animals (IA), a stable colloidal suspension of iron oxide, organic acids, and detergents, was tested in vitro and in vivo. In vitro assays were performed to test the unspecific inhibitory effect of IA on both gram-positive and gram-negative bacteria monitoring the microorganism growth by spectrophotometry (optical density OD600) ...
Boorman S, Boone LH, White A.To characterize the clinical features, treatment, and outcome of aural hematomas in horses. Methods: 7 horses with 1 or 2 aural hematomas (8 ears in total) treated at a veterinary teaching hospital in 2008 through 2019. Methods: Data retrieved from medical records included signalment, pertinent historical information, clinical signs, diagnostic procedures (including dermatologic assessment), and treatments. Case outcome was determined from documentation in the medical record or via telephone communication with owners or referring veterinarians. Results: 3 horses were presented after recurrence...
Stasiak K, Dunowska M, Trewick S, Rola J.Equid herpesvirus 5 (EHV-5) is one of two γ-herpesviruses that commonly infect horses worldwide. The objective of the study was to estimate the genetic variability within EHV-5 viruses circulating among horses in Poland. Partial glycoprotein B (gB) sequences from 92 Polish horses from 13 studs throughout Poland were compared to each other and to three EHV-5 sequences from other countries. Despite the overall high level of conservation, considerable variability was observed around the putative furin cleavage site. Based on phylogenetic analysis, the viruses clustered within two major lineages ...
Slater R, Frau A, Hodgkinson J, Archer D, Probert C.Anoplocephala perfoliata is a common equine tapeworm associated with an increased risk of colic (abdominal pain) in horses. Identification of parasite and intestinal microbiota interactions have consequences for understanding the mechanisms behind parasite-associated colic and potential new methods for parasite control. A. perfoliata was diagnosed by counting of worms in the caecum post-mortem. Bacterial DNA was extracted from colonic contents and sequenced targeting of the 16S rRNA gene (V4 region). The volatile organic compound (VOC) metabolome of colonic contents was characterised using gas...
van Dijk J.Jan van Dijk, RCVS specialist in veterinary parasitology, describes how data can be used to both increase understanding of trends in equine helminth abundance and drive better treatment of individual horses.
Zanet S, Battisti E, Labate F, Oberto F, Ferroglio E.Nematodes are an important cause of disease and loss of performance in horses. Changes in the parasitic fauna of horses have occurred in the past few decades, making cyathostomins the major parasites in adult horses, while large strongyles have become less prevalent. spp. remains the most important parasite infecting foals and weanlings. Anthelmintic resistance is highly prevalent in cyathostomins and spp. worldwide and it must be factored into treatment decisions. To assess anthelmintic efficacy in Northern Italy, we sampled 215 horses from 17 sport and horse-breeding farms. Fecal egg count...
Weese JS, Slovis N, Rousseau J.Understanding the epidemiology of Clostridium difficile is important for the development and assessment of infection prevention and control practices, as well as surveillance methods and interpretation of diagnostic testing results. Objective: Our objective was to longitudinally evaluate C. difficile shedding in neonatal foals and mares admitted to a referral hospital neonatal intensive care unit. Methods: Foals admitted to a neonatal intensive care unit, along with their dams. Methods: Rectal swabs were collected from mares and foals at admission, and then approximately every 3 days, when p...
Brennvall HM, Bjune T, Sverdrup Ø, Ráki M, Abedini S.Zoonoses are important to consider when humans become ill after being in contact with animals. In such cases thorough patient history is crucial, especially when infections have an unclear cause. We present a patient with infection-associated glomerulonephritis, where a horse was the probable source of infection. A young woman was admitted to the district general hospital in Vestfold, Norway, with infection and acute kidney failure. Renal biopsy suggested glomerulonephritis, and nasopharyngeal culture taken at admission detected Streptococcus equi. It emerged that the patient had daily contact...
Borba LA, Nogueira CEW, Bruhn FRP, da Silva GC, Feijó LS, Canisso IF, Curcio BDR.Neonatal sepsis is a leading cause of neonatal death during the first-week postfoaling. Despite recent advancements in the diagnosis and treatment of sepsis in the newborn foal, the non-specific clinical signs and subtle nature of this disease may result in delayed diagnosis until severe progression of the disease; thus, early detection of sepsis remains critical for a favourable outcome. This study aimed to identify early blood markers as predictive of sepsis on foals. Thirty-five foals were allocated into three groups: healthy control foals (n=7) and foals born from mares with placentitis: s...
Bastos RG, Sears KP, Dinkel KD, Kappmeyer L, Ueti MW, Knowles DP, Fry LM.The apicomplexan parasite is one of two known causative agents of equine theileriosis. It causes milder clinical disease than its more virulent counterpart, , in experimentally infected horses, and can superinfect -positive horses. The current equi merozoite antigen 1 (EMA1)-based competitive enzyme-linked immunosorbent assay (ELISA)used in the U.S. to detect equine theileriosis detects but not , and the complexity of molecular assays precludes widespread use for epidemiologic studies. In order to facilitate urgently needed studies on the prevalence of , the goal of this study was to develop...
Pan W, Shen Z, Wang H, He H.Vesicular stomatitis virus (VSV) is an archetypal member of Mononegavirales which causes important diseases in cattle, horses and pigs. The matrix protein (M) of VSV plays critical roles in the replication, assembly/budding and pathogenesis of VSV. To further investigate the role of M during viral growth, we used a two-hybrid system to screen for host factors that interact with the M protein. Here, NADH: ubiquinone oxidoreductase complex assembly factor 4 (Ndufaf4) was identified as an M-binding partner, and this interaction was confirmed by yeast cotransformation and GST pulldown assays. ...
Muraro LS, Souza AO, Leite TNS, Cândido SL, Melo ALT, Toma HS, Carvalho MB, Dutra V, Nakazato L, Cabezas-Cruz A, Aguiar DM.The genus includes tick-borne bacterial pathogens affecting humans, domestic and wild mammals. has been identified in different animal species and geographical locations, suggesting that this is a widely distributed and generalist . In the present study, we evaluated infection in 148 Equidae presented to the Medical Clinic Department of a Veterinary Hospital from a midwestern region of Brazil. Blood samples and ticks collected from the animals were tested by Polymerase Chain Reaction (PCR) for the presence of spp. A multigenic approach including Anaplasmataceae-specific (i.e., 16S rRNA, , ...
Satué K, Gardon JC, Muñoz A.Myeloid disorders are conditions being characterized by abnormal proliferation and development of myeloid lineage including granulocytes (neutrophils, eosinophils and basophils), monocytes, erythroids, and megakaryocytes precursor cells. Myeloid leukemia, based on clinical presentation and proliferative rate of neoplastic cells, is divided into acute (AML) and myeloproliferative neoplasms (MPN). The most commonly myeloid leukemia reported in horses are AML-M4 (myelomonocytic) and AML-M5 (monocytic). Isolated cases of AML-M6B (acute erythroid leukemia), and chronic granulocytic leukemia have al...
Raidal SL, Hughes KJ, Eastwell B, Noble N, Lievaart J.There is little information on foal mortality and the epidemiology of diseases in the neonatal period in Australian equine breeding enterprises. Methods: This was a prospective cohort study of 1219 foals on 15 breeding farms in south-eastern Australia to identify the proportion of foals recognised on farm as abnormal at birth or within the first 48 h postpartum, determine the prevalence and risk factors for neonatal disease and assess the subsequent performance of foals in the study population. Results: Overall, 27 foals died within 6 weeks of birth in the study population (2.2%), 142 foal...
Valcek A, Sismova P, Nesporova K, Overballe-Petersen S, Bitar I, Jamborova I, Kant A, Hrabak J, Wagenaar JA, Madec JY, Damborg P, van Duijkeren E....The relatedness of the equine-associated ST1250 and its single- and double-locus variants (ST1250-SLV/DLV), obtained from horses in Europe, was studied by comparative genome analysis. A total of 54 isolates of ST1250 and ST1250-SLV/DLV from healthy and hospitalized horses across Europe [Czech Republic (n=23), the Netherlands (n=18), Germany (n=9), Denmark (n=3) and France (n=1)] from 2008-2017 were subjected to whole-genome sequencing. An additional 25 draft genome assemblies of ST1250 and ST1250-SLV/DLV were obtained from the public databases. The isolates were compared for genomic feature...
Nath LC, Elliott AD, Weir J, Curl P, Rosanowski SM, Franklin S.Atrial fibrillation (AF) impacts performance and horse and jockey safety. Understanding the outcomes of AF identified postrace will better inform regulatory policy. Objective: To investigate the outcomes after episodes of AF identified postrace and determine whether affected horses are at increased risk of additional episodes compared to the general racing population. Methods: Total of 4684 Thoroughbred racehorses. Methods: Race records for Thoroughbred horses racing in Hong Kong from 2007 to 2017 were reviewed. Horses that performed below expectation were examined by cardiac auscultation and ...
Conrado FO, Beatty SSK.Fluid analysis is an important part of the diagnostic work-up of equine patients presenting with disorders of the nervous system, musculoskeletal system, and abdominal cavity. Proper specimen handling and processing are paramount for complete and accurate interpretation of fluid samples. Normal cerebrospinal fluid is a low-cellularity, low-protein fluid requiring specific sample handling to ensure accurate results. Joint and abdominal fluid analyses are completed in practice or submitted for analysis to a reference laboratory. This article discusses fluid sample handling and processing conside...
Doerksen T, Bird E, Henningson J, Palinski R.Here, we report the near-complete genome sequences of vesicular stomatitis virus (VSV) serotype Indiana isolates from the 2020 U.S. outbreak. The sequences were obtained from swabs collected from Kansas horses in July and August. The four genome sequences help improve our understanding of VSV outbreak dynamics in the United States.
Tucker R, Hall YS, Hughes TK, Parker RA.Computed tomography (CT) imaging of the cervical spine of mature horses under general anaesthesia is becoming increasingly accessible. Osteochondral fragmentation (OF) of the cervical articular process joints (APJs) has been identified on CT imaging; the prevalence, clinical features and significance of this finding are currently unknown. Objective: To describe the prevalence and clinical features of a population of horses with CT evidence of OF within the cervical APJs. Methods: Retrospective, descriptive case series. Methods: The study population consisted of all horses undergoing CT imaging...
Bogdan AM, Ionita M, Mitrea IL.The purpose of this study was to investigate the seroprevalence of selected tick-borne-pathogens (TBPs) among Romanian horses. For this, a total of 223 animals originating from north, central, and southeast Romania, including horses from stud farms ( = 118) and working horses ( = 105), were tested using a commercial rapid ELISA-based test. Overall, 10.3% (95% confidence interval (CI): 6.7-15.1%) of the tested horses were seropositive for antibodies (Ab) against Additionally, 18.8% (95% CI: 13.9-24.6%) and 0.5% (95% CI: 0.01-2.5%) of horses were seropositive for Ab against sensu lato and spp...
Bradbery AN, Coverdale JA, Hartz CJ, Millican AA, Goehring MS, Fikes KK, Picking E, Hammer CJ, Dunlap KA, Cardoso RC, Wickersham TA, Leatherwood JL....Results from previous studies indicate that maternal overnutrition during late gestation predisposes foals to metabolic disease, however, specific mechanisms resulting in disease remain unknown. Quarter Horse mares (n = 16), were randomly assigned to dietary treatments, beginning on gestational day 235, and consisted of a control group (CON- diet meeting nutrient requirement; n = 8) or an overfed diet (HIGH; n = 8) where mares received an additional 40 % above CON. On gestational days 285 and 315, an intravenous glucose tolerance test (FSIGTT) was conducted. Following parturition, foals were s...
Nowacka-Woszuk J, Mackowski M, Stefaniuk-Szmukier M, Cieslak J.The equine graying with age causative mutation in the syntaxin-17 gene (STX17) has been known for over a decade, but proper genotyping of this variant remains challenging due to its molecular character (4.6-kb tandem duplication). Precise information on gray mutation status is important for horse breeders and veterinarians, since gray homozygous horses are more prone to developing aggressive melanoma tumors than heterozygotes. Since recent studies have confirmed that droplet digital PCR is a valuable technique for copy number analysis, we decided to investigate whether this method can be used ...
Cooper CJ, Arroyo LG, Pearl DL, Hewson J, Lillie BN.A survey of Ontario horse breeders was conducted in 2016 and retrospectively asked farm-level management questions regarding herd sizes, vaccination, respiratory disease, and abortion over the years 2014 to 2015. A total of 88 farm owners completed the survey, reporting 857 broodmares. Using logistic regression modelling, management influences on vaccine use, and the reporting of respiratory disease or abortion was investigated. Having veterinary records and the reasons for breeding were significantly associated with the odds of an abortion even after controlling for broodmare herd size. The o...
Oláh T, Cai X, Michaelis JC, Madry H.The human knee is a complex joint, and affected by a variety of articular cartilage disorders. Large animal models are critical to model the complex disease mechanisms affecting a functional joint. Species-dependent differences highly affect the results of a pre-clinical study and need to be considered, necessitating specific knowledge not only of macroscopic and microscopic anatomical and pathological aspects, but also characteristics of their individual gait and joint movements. Methods: Literature search in Pubmed. Conclusions: This narrative review summarizes the most relevant anatomical s...
Buckley T, McManamon E, Stanbridge S.This study sought to determine whether an increase in resistance of Rhodococcus equi to the antibiotics rifampin and erythromycin occurred over a 10-year period. This was carried out by the use of E test strips for rifampin and erythromycin to determine the MIC (minimum inhibitory concentration) values of Rhodococcus equi to this combination of antibiotics.The findings of this study indicated that there was an increase in resistance of Rhodococcus equi to rifampin and erythromycin over the 10-year period. The MIC for rifampin increased from 0.081 μg/ml in 1996 to 0.187 μg/ml in 2006 and from...
Biswas B, Mukherjee D, Mattingly-Napier BL, Dutta SK.Genomic amplification by the polymerase chain reaction (PCR) was used to identify a unique genomic sequence of Ehrlichia risticii directly in DNA isolated from peripheral-blood buffy coat cells of E. risticii-infected horses (Potomac horse fever) and from infected cell cultures. A specific primer pair, selected from a cloned, species-specific, 1-kb DNA fragment of the E. risticii genome as a template, was used for the amplification of the target DNA of 247 bp. The optimal number of 40 PCR cycles, determined by analyzing an amplification profile obtained with a constant Taq polymerase concentra...
Donabedian SM, Perri MB, Abdujamilova N, Gordoncillo MJ, Naqvi A, Reyes KC, Zervos MJ, Bartlett P.Vancomycin-resistant enterococci are a major cause of nosocomial infections but are rarely found in humans in the community and have not been identified in food animals in the United States. We evaluated a total of 360 fecal specimens from humans and their animals being raised for exhibit at three county fairs in Michigan. Fecal samples from 158 humans, 55 swine, 50 cattle, 25 horses, 57 sheep, 14 goats, and 1 llama were obtained and plated onto Enterococcosel agar containing 16 μg/ml of vancomycin. Vancomycin-resistant Enterococcus faecium (VREF) was isolated from six pigs but not from human...
Cimprich RE, Rooney JR.Corynebacterium equi is a pathogen associated with respiratory disease in the foal. This paper discusses two cases of Corynebacterium equi infection, one acute and one chronic, in which the major damage was intestinal. Necrosis of Peyer's patches was the only lesion seen in the small intestine of both foals. The foal with acute disease had distinct green-tan focal necrosis and thickened mucosa of the large intestine. In the foal with chronic disease, the mucosa of the large intestine was thickened, rugose, and mottled red-tan. Histologically, the predominant lesions were villous atrophy, mucos...
Ibrayev B, Lider L, Bauer C.A cross-sectional survey was performed to obtain current data on the gastrointestinal myiasis of horses in the provinces of Kostanay, Akmola and Karagandy, northern and central Kazakhstan. The stomach, small intestine and rectum of 148 slaughter horses were examined for Gasterophilus spp. larvae during a 26-month study period. All horses were infected with 2nd and 3rd stage larvae (mean intensity: 803±350), and 22% of them harboured >1000 Gasterophilus spp. larvae each. Four species were identified: G. intestinalis (prevalence: 100%; mean intensity: 361±240 larvae), G. haemorrhoidalis (100%;...
Pusterla N, Wattanaphansak S, Mapes S, Collier J, Hill J, Difrancesco M, Gebhart C.Equine proliferative enteropathy (EPE) is an emerging disease of weanling foals. Objective: Describe clinical, hematologic, biochemical, serologic, molecular, and ultrasonographic findings in foals experimentally infected with Lawsonia intracellularis. Methods: Eight foals. Methods: Recently weaned foals were assigned to either the challenge (n = 3), the sentinel (n = 3), or the control (n = 2) group. Foals were experimentally challenged via intragastric inoculation of 3 x 10(10)L. intracellularis organisms grown in culture. Each experimentally infected foal was housed with a sentinel foal in ...
Patterson-Kane JC, Caplazi P, Rurangirwa F, Tramontin RR, Wolfsdorf K.Encephalitozoon cuniculi is a microsporidial parasite, which has rarely been reported to cause placentitis in animals. A late-term aborted fetus and placenta from a Quarterhorse were presented to the Livestock Disease Diagnostic Center, University of Kentucky, for diagnostic examination. There was a necrotizing placentitis, with distension of many chorionic epithelial cells by intracytoplasmic vacuoles containing 1-2-microm-diameter, elongated, gram-positive organisms. The organisms were identified as E. cuniculi by electron microscopy and by polymerase chain reaction using primers to microspo...
Bullone M, de Lagarde M, Vargas A, Lavoie JP.The identification of serum biomarkers of lung inflammation would facilitate the diagnosis of inflammatory airway disease (IAD) in horses. Objective: Horses with IAD have higher serum concentrations of markers of inflammation compared to controls. Methods: Twelve horses with IAD and 10 control horses. Methods: This was a prospective case-control study. Blood and BALF were collected from horses with IAD and controls. Serum concentration of surfactant protein D (SP-D), haptoglobin, serum amyloid A (SAA) and of the soluble form of triggering receptor expressed on myeloid cells 1 (sTREM-1) was mea...
Clarke LL, Roberts MC, Argenzio RA.The association of feeding practices with the development of digestive disorders in horses has long been recognized, although the underlying mechanisms had been barely considered. The physiologic consequences of meal frequency may help to explain the relationship and prove to be of major significance in the induction of many conditions. Many Equidae kept for performance and leisure activities are fed high-energy, low-forage rations twice daily, with limited access to hay or grazing. Rapid ingestion of such meals stimulates a copious outpouring of upper alimentary secretions and results in tran...
Payne SL, La Celle K, Pei XF, Qi XM, Shao H, Steagall WK, Perry S, Fuller F.The Wyoming strain of equine infectious anaemia virus (EIAV) is a highly virulent field strain that replicates to high titre in vitro only in primary equine monocyte-derived macrophages. In contrast, Wyoming-derived fibroblast-adapted EIAV strains (Malmquist virus) replicate in primary foetal equine kidney and equine dermis cells as well as in the cell lines FEA and Cf2Th. Wyoming and Malmquist viruses differ extensively both in long terminal repeat (LTR) and envelope region sequences. We have compared the promoter activities of the Wyoming LTR with those of LTRs derived from fibroblast-adapte...
Burns EN, Finno CJ.Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy is an inherited neurodegenerative disorder affecting many horse breeds. Clinical signs include a symmetric ataxia and an abnormal stance at rest, similar to cervical vertebral compressive myelopathy, equine protozoal myeloencephalitis, and equine herpesvirus 1 myeloencephalopathy. This review will provide an update on the disease prevalence, management, impact, and ongoing research.
Ehizibolo DO, Gusi AM, Ehizibolo PO, Mbuk EU, Ocholi RA.Despite the endemicity of brucellosis in Nigeria, reports on equine brucellosis are rare. The Rose Bengal Plate Test (RBPT) was used to determine the serologic prevalence of Brucella abortus antibodies amongst 75 horses from three stables in two States of northern Nigeria. The highest prevalence (22.7%) was recorded in stable C located in Plateau State and the lowest (6.7%) was found in stable B in Kaduna State. The overall prevalence determined was 14.7%. There is need for the inclusion of horses in brucellosis surveillance and control strategies in Nigeria to safeguard people at high risk.
Rosa M, Cardozo LM, da Silva Pereira J, Brooks DE, Martins AL, Florido PS, Stussi JS.The conjunctival fungal flora of 32 adult horses with normal eyes (n = 64) from the State of Rio de Janeiro in Brazil was identified in the fall of 2000 using horses of different breeds, both genders and aged 5-19 years old. The culture samples were taken from the conjunctival sac of both eyes with a sterile cotton swab wetted with saline solution, seeded in Sabouraud's dextrose agar with chloramphenicol, and incubated for 5 days at an average temperature of 25 degrees C. The number of fungal colonies per eye varied between 0 and 250 colony forming units (CFUs). There were often differences in...
Theodoridis A, Nevill EM, Els HJ, Boshoff ST.Five viruses, unrelated to bovine ephemeral fever virus (BEFV), were isolated from Culicoides biting-midges collected during the summer months of the years 1968-69 and 1969-70 near a cattle herd in which cases of BEF occurred and at an open horse stable at Onderstepoort. These viruses were investigated by means of serological, electron-microscopical and physicochemical tests. It was established that 2 isolates, Cul. 1/69 and Cul. 2/69, were related to each other and belonged to the Palyam subgroup of the genus Orbivirus, that isolate Cul. 3/69 belonged to the equine encephalosis subgroup of th...
Perryman LE, Torbeck RL.A 3-year prospective breeding trial was designed to verify the mode of inheritance of combined immunodeficiency (CID) in Arabian horses. Twenty-six mares that had previously produced foals with CID were mated to a stallion that had sired foals with CID. Of 53 foals obtained, 15 (28.3%) had CID. The ratio of female to male foals was 28:25, and the ratio of female CID to male CID foals was 8:7. The results of this trial confirmed a suggestion that CID in Arabian horses is inherited as an autosomal recessive trait.
Lazary S, Gerber H, Glatt PA, Straub R.The distribution of equine leucocyte antigens (ELA) in horses affected by equine sarcoid tumours was determined and compared with unaffected controls. ELA-haplotype W3,B1 occurred more frequently in affected riding horses of Irish, Swiss and French background. The combined data for the three breeds resulted in a chi 2 value of 20.35 (P less than 0.0005 after correction). Simultaneously, ELA-specificity W11 was more frequently found in horses of Irish background, while W5 was found in Swiss and French horses with sarcoids. The combined data for haplotype W3,B1 and/or W5 specificity demonstrated...
Roberts V.Trigeminal-mediated headshaking is a little-understood neuropathic facial pain condition of the horse. The condition may affect around 1% of the equine population to a degree of severity sufficient to require veterinary attention. As a pain condition, this represents a significant welfare issue. Horses are usually more severely affected at exercise which can leave them unable to perform, or even dangerous to ride and handle. With little known about the condition and variable response to treatments, severely affected horses are often euthanized. This review article considers the literature on t...
Cordes DO, Perry BD, Rikihisa Y, Chickering WR.Potomac horse fever was reproduced in 15 ponies by transfusion of whole blood originally from two natural cases and subsequently from ponies infected by the transfusions. Incubation periods varied from 9 to 15 days. Affected ponies developed varying degrees of fever, diarrhea, anorexia, depression, and leukopenia. Eleven affected ponies were killed, three died in the acute phase of the disease, and one did not show clinical signs. The most consistent post-mortem findings were fluid contents in the cecum and large colon, and areas of hyperemia (of inconstant degree and distribution) in mucosae ...
Venter GJ, Paweska JT.Previously reported virus recovery rates from Culicoides (Avaritia) imicola Kieffer and Culicoides (Avaritia) bolitinos Meiswinkel (Diptera, Ceratopogonidae) orally infected with vaccine strain of African horse sickness virus serotype 7 (AHSV-7) were compared with results obtained from concurrently conducted oral infections with five recent AHSV-7 isolates from naturally infected horses from various localities in South Africa. Culicoides were fed sheep bloods spiked with 10(7.6) TCID(50)/mL of a live-attenuated vaccine strain AHSV-7, and with five field isolates in which virus titre in the blo...
Grinberg A, Learmonth J, Kwan E, Pomroy W, Lopez Villalobos N, Gibson I, Widmer G.Cryptosporidium isolates from diarrheic foals in New Zealand (n = 9) were identified as C. parvum, subtyped at two polymorphic loci, and compared with human (n = 45) and bovine (n = 8) isolates. Foal C. parvum isolates were genetically diverse, markedly similar to human and bovine isolates, and carried GP60 IIaA18G3R1 alleles, indicating a zoonotic potential.
Certoma A, Lunt RA, Vosloo W, Smith I, Colling A, Williams DT, Tran T, Blacksell SD.Australian bat lyssavirus (ABLV) is closely related to the classical rabies virus and has been associated with three human fatalities and two equine fatalities in Australia. ABLV infection in humans causes encephalomyelitis, resulting in fatal disease, but has no effective therapy. The virus is maintained in enzootic circulation within fruit bats ( spp.) and at least one insectivorous bat variety ( ). Most frequently, laboratory testing is conducted on pteropodid bat brains, either following a potential human exposure through bites, scratches and other direct contacts with bats, or as opportun...
Bordin AI, Liu M, Nerren JR, Buntain SL, Brake CN, Kogut MH, Cohen ND.Rhodococcus equi is an intracellular bacterium that causes pneumonia in foals and immunocompromised adult horses. Evidence exists that foals become infected with R. equi early in life, a period when innate immune responses are critically important for protection against infection. Neutrophils are innate immune cells that play a key role in defense against this bacterium. Enhancing neutrophil function during early life could thus help to protect foals against R. equi infection. The objective of our study was to determine whether in vitro incubation with the TLR9 agonist CpG 2142 would enhance d...
Tallmadge RL, McLaughlin K, Secor E, Ruano D, Matychak MB, Flaminio MJ.Many features of the equine immune system develop during fetal life, yet the naïve or immature immune state of the neonate renders the foal uniquely susceptible to particular pathogens. RT-PCR and immunohistochemical experiments investigated the progressive expression of developmental B cell markers and immunoglobulins in lymphoid tissues from equine fetus, pre-suckle neonate, foal, and adult horses. Serum IgM, IgG isotype, and IgA concentrations were also quantified in pre-suckle foals and adult horses. The expression of essential B cell genes suggests active development and gene recombinati...