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.
Rubio C, Cubillo MA, Hooghuis H, Sanchez-Vizcaino JM, Diaz-Laviada M, Plateau E, Zientara S, Crucière C, Hamblin C.The mortality rate in susceptible populations of horses during an epizootic of African horse sickness (AHS) may be in excess of 90%. Rapid and reliable assays are therefore essential for the confirmation of clinical diagnoses and to enable control strategies to be implemented without undue delay. One of the major objectives of a recent European Union funded project was the validation of newly developed diagnostic assays which are rapid, sensitive, highly reproducible and inexpensive, for the detection of African horse sickness virus (AHSV) antigens and antibodies. The Laboratorio de Sanidad y ...
Zientara S, Sailleau C, Moulay S, Crucière C, el-Harrak M, Laegreid WW, Hamblin C.A coupled reverse transcriptase-polymerase chain reaction assay (RT-PCR) for the detection of African horse sickness virus (AHSV) dsRNA, has been developed using genome segment 7 as the target template for primers. RNA from isolates of all nine AHSV serotypes were readily detected. The potential inhibitory effects of either ethylene diamine tetra acetic acid (EDTA) or heparin on the RT-PCR were eliminated by washing blood samples before lysis of the red blood cells and storage. There was a close agreement in the sensitivity and the specificity of the RT-PCR and an indirect sandwich ELISA. Conf...
Katz JB, Alstad D, Jenny AL, Carbone KM, Rubin SA, Waltrip RW.Borna disease was originally described as an equine neurologic syndrome over 200 years ago, although the infectious etiology of the disorder was unproven until the early 20th century. Borna disease virus (BDV) was finally isolated from horses dying of the disorder, and that virus has been used to experimentally reproduce Borna disease in several species of laboratory animals. However, BDV has never been inoculated back into horses to experimentally and etiologically confirm the classic clinical, pathologic, and serologic characteristics of the disease in that species. Three ponies were intrace...
Hamblin C, Salt JS, Mellor PS, Graham SD, Smith PR, Wohlsein P.Investigations have been carried out to elucidate the possible role of the donkey in the epidemiology of African horse sickness (AHS). These studies have shown that despite the absence of pyrexia or other observable clinical signs, donkeys become infected with virulent AHS virus serotype 4 (AHSV 4) and that they develop a viraemia which can persist for at least 12 days, albeit at a comparatively lower titre than that recorded for similarly infected ponies. AHSV 4 showed a similar tissue tropism in the pony and donkey but the virus appeared to replicate less efficiently in donkey tissues. The o...
Archambault D, Laganière G, St-Laurent G.The genetic variation in equine arteritis virus (EAV) nonstructural (NS) protein-encoding open reading frames (ORF) 3 and 4 genes was investigated. Nucleotide and deduced amino acid sequences from seven different EAV isolates (one European, one American and five Canadian isolates) and the Arvac vaccine strain were compared with those of the Bucyrus reference strain. ORF 3 nucleotide and amino acid sequence identities amongst these isolates (including the Arvac vaccine strain) and the Bucyrus reference strain ranged from 85.6 to 98.8%, and 85.3 to 98.2%, respectively, whereas ORF 4 nucleotide a...
Huovilainen A, Ek-Kommonen C.A serological study for antibodies against equine arteritis virus (EAV) in Finland was performed during 1996. All equine sera delivered to the Virology Unit at the National Veterinary and Food Research Institute were tested with a micro-neutralization test, using the Arvac strain as antigen. The study also included imported horses to evaluate EAV circulation in the countries of origin. Nucleocapsid gene sequences of 2 Finnish equine semen isolates were amplified with RT-PCR and sequenced. The genetic relationships of those isolates with strains isolated elsewhere in the world were analyzed. Th...
Evans TJ, Miller MA, Ganjam VK, Niswender KD, Ellersieck MR, Krause WJ, Youngquist RS.To develop an objective, quantifiable assay for endometrial periglandular fibrosis (EPF) and correlate assay results with histologic and ultrastructural changes in equine endometrial biopsy specimens. Methods: Endometrial biopsy specimens from 70 mares from 3 to 27 years old in estrus. Methods: In a double-blinded study design, endometrial biopsy specimens were graded histologically (modified Kenney classification) for EPF and inflammation. Endometrial periglandular collagen volume fraction (%EPCVF) was determined by light microscopic image analysis of picrosirius red-stained sections. Specime...
McClanahan S, Hunter J, Murphy M, Valberg S.Propylene glycol and mineral oil are commonly used in the veterinary profession for treatment of bovine ketosis and equine impactions, respectively. Accidental administration of 6.0 ml propylene glycol/kg of body weight in horses causes severe depression, ataxia and malodorous breath and feces. However, appropriate medical therapy can result in successful treatment of this toxicosis.
Krieger RI, South P, Mendez Trigo A, Flores I.Methomyl (S-methyl-N-((methylcarbamoyl)oxy) thioacetimidate) toxicity was studied in horses using i.v. dosages from 0.01 to 3.0 mg/kg. Doses of 1-3 mg methomyl/kg produced increased GI motility and respirations, facial fasiculations, salivation, lacrimation and convulsions. The only effect at 0.5 mg/kg was increased GI sounds in 1/4 horses. This extensively used crop insecticide had been associated with episodes of morbidity and mortality and led to speculation that it was extremely potent to the horse. This was not supported by these clinical studies.
Lichtenfels JR, Kharchenko VA, Krecek RC, Gibbons LM.The results of an international collaborative effort to prepare a recommended list of scientific names for the small strongyles (Nematoda: Strongyloidea: Cyathostominea) of horses, donkeys and zebras are reported. Fifty-one valid species are recognized in 13 genera, including Cyathostomum, Coronocyclus, Cylicodontophorus, Cylicocyclus, Cylicostephanus, Skrjabinodentus, Tridentoinfundibulum, Petrovinema, Poteriostomum, Parapoteriostomum, Hsiungia, Cylindropharynx and Caballonema. In addition, 42 other species level names are listed as synonyms of the 51 recognized species or as species inquiren...
Maury W, Oaks JL, Bradley S.Previous cell infectivity studies have demonstrated that the lentivirus equine infectious anemia virus (EIAV) infects tissue macrophages in vivo and in vitro. In addition, some strains of EIAV replicate to high titer in vitro in equine fibroblasts and fibroblast cell lines. Here we report a new cell type, macrovascular endothelial cells, that is infectible with EIAV. We tested the ability of EIAV to infect purified endothelial cells isolated from equine umbilical cords and renal arteries. Infectivity was detected by cell supernatant reverse transcriptase positivity, EIAV antigen positivity wit...
Benbarek H, Deby-Dupont G, Caudron I, Grülke S, Deby C, Lamy M, Serteyn D.In horses, the mechanisms of lipopolysaccharide (LPS) stimulation of isolated neutrophils to produce reactive oxygen species remain unknown. We re-investigated this problem by monitoring the luminol-enhanced chemiluminescence (CL) produced by LPS-stimulated equine neutrophils. The neutrophils were isolated from horse blood by discontinuous density gradient centrifugation (> or = 99% neutrophils; viability > or = 98%). Increasing concentrations of Escherichia coli (E. coli) LPS (from 0.01-10 microg ml(-1)) were used to activate the neutrophils. When LPS was used directly, without another ...
Brown CM, Timoney PJ.An outbreak of disease, characterized by depression, anorexia, fever, limb oedema and lymphocytopenia, occurred on a farm for thoroughbreds in India in 1990. Twenty-six of the 88 horses on the farm were affected, predominantly adults. Signs were present in affected horses for 7-10 days, and the outbreak lasted 21 days. Seven of the 26 affected horses were tested for exposure to Getah virus using paired serum samples, acute and convalescent. Four of the 7 horses seroconverted to Getah virus, and the other three showed a 4-fold or greater rise in titre. The clinical and laboratory findings were ...
Pirie RS, Mayhew IG, Clarke CJ, Tremaine WH.Intraoperative brain ultrasonography is commonly used clinically
in human and canine neonates (Johnson and Rumack 1980;
Babock and Han 1981; Cappe and Lam 1985; Hudson et al. 1990,
1991) and a single report exists of its use to assist in defining
hydrocephalus in an equine neonate (Foreman et al. 1983). This
technique has also been reported to be clinically useful in human
adults (Rubenstein et al. 1984) and ultrasound-guided brain biopsy
has also been described in mature dogs (Thomas et al. 1993).
%ours of the central nervous system in the horse are
extremely rare, with the exception...
Davis MS, Murray MJ, Donaldson LL.There are limited methods of assessing pulmonary function in horses at rest. We developed clinical techniques to measure gas exchange efficiency in horses and evaluated 3 groups of horses that were 1) asymptomatic based on auscultation with rebreathing, transtracheal aspirate cytology, and thoracic radiographs (n = 6), 2) asymptomatic at rest but symptomatic with rebreathing (n = 11) and 3) symptomatic at rest (n = 9). Blood samples were obtained from the transverse facial artery and jugular vein. Maximal end-tidal CO2 tension (PETCO2) was measured by an infrared capnograph through a facemask....
Holly EA, Bracci PM, Mueller BA, Preston-Martin S.Nineteen counties from San Francisco and Los Angeles, California and Seattle, Washington were the United States sites for a large population-based case-control study of childhood brain tumors (CBTs), sponsored by the National Cancer Institute. CBT patients who were 1 year and were first on a farm when they were < 6 months of age also had increased risk for CBTs (OR = 3.9, 95% CI = 1.2-13). A somewhat increased risk for CBTs was found for children of mothers who ever had worked on livestock farms compared with mothers who never had worked on a farm (OR = 7.4, 95% CI = 0.86-64, based on five...
Bacon Miller C, Wilson DA, Martin DD, Pace LW, Constantinescu GM.A 3-year-old Quarter Horse gelding was treated for left guttural pouch mycosis by ligation and balloon catheterization of the left internal carotid artery. Catheter advancement was shorter (10 cm) than the normally reported distance (13-15 cm), but was observed endoscopically during placement as it coursed within the internal carotid artery through the guttural pouch. The horse developed a persistently abnormal respiratory pattern after catheter placement, failed to gain consciousness, developed pulmonary edema, and died 5.5 hours postoperatively. Postmortem examination revealed an aberrant le...
Huovinen S, Tunnela E, Huovinen P, Kuijpers AF, Suhonen R.We report fingernail onychomycosis caused by Trichophyton equinum in a farmer who breeds racehorses. In addition to the thumbnail, T. equinum had infected one of the racehorses. Oral terbinafine cured the infection in the farmer.
Crabill MR, Schumacher J.Periodontitis, infundibular necrosis, and periapical infection are dental diseases commonly affecting adult horses. Routine dental examinations and care may help to prevent these diseases. Further investigation of the treatment of horses with these diseases using local antimicrobial therapy, restorative dentistry, and endodontic therapy is needed. An understanding of the pathogenesis of these diseases aids in diagnosis and treatment. Gingival hyperplasia and odontogenic tumors are uncommon but should remain in a list of differential diagnoses when examining a horse with pertinent clinical sign...
Easley J.This article explains what is needed for successful extraction of diseased cheek teeth and how to realign the occlusal surface. Incisor teeth procedures and correcting abnormalities of cheek tooth crown wear are also discussed along with wolf and floating teeth.
DeBowes RM, Gaughan EM.Equine congenital dental deformities are not limited merely to those presented here; however, the examples discussed offer the reader an appreciation for the range of severity and complexity that may be found in affected horses. The veterinarian is obligated to provide the best possible care for the patient and to relieve animal suffering. The lack of definitive evidence for heritability of many of these defects can place the veterinarian in an untenable position, particularly when presented with literature that proclaims or suggests without evidence that a particular condition is inherited. I...
Hoque S, Derar RI, Senba H, Osawa T, Kano K, Taya K, Miyake Y.To clarify the morphological and immunohistochemical characteristics in mares with granulosa theca cell tumor (GTCT), the localization of inhibin subunits (alpha, betaA, betaB) and aromatase in the granulosa cell layers and theca layers in the ovarian follicles were determined by immunohistochemical staining. The follicles were obtained from the ovaries of 6 mares with GTCT and 4 normal mares as controls. Immunohistochemically, inhibin alpha-subunit was localized in the granulosa cells of all follicles showing different sizes in all GTCT cases and betaA- subunit was localized in two GTCT cases...
Rebhun WC.Corneal squamous cell carcinomas with surface areas of more than 2.0 cm were diagnosed in 26 eyes of 25 horses. The depth of the lesion into the corneal stroma and involvement of the ocular adnexa were important determinants for surgical treatment. Corneal tumors that extended into adjacent palpebral conjunctiva, eyelid, or orbit were not amenable to complete excision, while those that involved only cornea and bulbar conjunctiva were treated surgically by keratectomy and beta radiation. Initial treatment was keratectomy followed by beta radiation on 24 eyes and enucleation of two eyes. Twenty ...
Parker RA, Bladon BM, McGovern K, Smith KC.To describe and discuss previously unreported complications associated with intraosseous perfusion with gentamicin in horses. Methods: Case report. Methods: Ten-year-old Warmblood gelding. Methods: Intraosseous perfusion with gentamicin into the proximal phalanx (P1) was used as part of the treatment regimen for distal interphalangeal joint and navicular bursa synovial sepsis. Although the sepsis responded favorably complications developed at the perfusion site, including persistent osteomyelitis, progressive osteonecrosis, and ultimately pathologic fracture of P1. Results: The progression of ...
Ganjam VK, McLeod C, Klesius PH, Washburn SM, Kwapien R, Brown B, Fazeli MH.The reaction between ovarian hormones and experimental uterine infection (Streptococcus zooepidemicus) was investigated in 3 groups, each containing 6 ovariectomized mares. Group 1 served as controls ('anoestrus'), Group 2 mares were injected with oestrogen ('oestrus') and Group 3 with progesterone ('dioestrus') over a period of 5 weeks. All mares received an intrauterine inoculation of the bacteria 1 week after the start of hormonal treatment, and the results of the challenge were examined by endometrial biopsy and swabs once weekly. At the end of Week 1 no bacteria were recovered from the ma...
Ruggles AJ, Ross MW.Medical records of 28 horses with impaction of the small colon were reviewed; 20 horses were admitted during the winter months. Diagnosis of small-colon impaction was made in 21 horses by rectal examination, and in 7 horses at exploratory celiotomy. Ten horses were treated medically, and 18 were treated surgically. Horses that were treated surgically were more likely to have abdominal distention than were those that responded to medical treatment (P less than 0.025). Signs of greater degree of abdominal pain and higher heart rate were seen in horses treated surgically, but these values were no...
McGuire TC, Banks KL, Evans DR, Poppie MJ.Agammaglobulinemia was diagnosed in a 1-year-old Thoroughbred horse on the basis of the following observations: (1) absence of serum immunoglobulins M, A, and G(T); (2) small amounts of serum immunoglobulin G (16 mg/100 ml); (3) absence of specific antibody in the serum of the horse following immunization and challenge exposure to 2 antigens; (4) absence of plasma cells, primary follicles, and germinal centers in a lymph node removed after antigenic stimulation; (5) absence of "natural" serum antibodies to rabbit-erythrocytes which were easily detectable in age-matched control horse serums; an...
Mawhinney I, Errington J, Stamper N, Torrens N, Engelsma MY, Roest HIJ.Sets of genital swabs are routinely taken from horses to screen for the presence of Taylorella equigenitalis, the cause of contagious equine metritis. Typically, two to four different sites are swabbed at a time and tested by culture or PCR. Objective: This study explored the feasibility of pooling these swabs for a single PCR test per animal instead of testing each swab individually. Methods: In vitro. Methods: PCR signal strengths (Ct values) from 149 historical PCR positive genital swabs, together with historical data on the number of swabs in a set expected to be positive, were used to ass...
Vest DJ, Cohen ND, Berezowski CJ, Morehead JP, Blodgett GP, Blanchard TL.To determine whether administration of killed West Nile virus vaccine was associated with pregnancy loss among broodmares. Methods: Retrospective cohort study. Methods: 595 mares. Methods: Records of pregnant mares with known vaccination history from 4 farms were reviewed. Information obtained from 595 mares included mare's identification; farm; age; breed; reproductive status; last breeding date; date last known pregnant; vaccination date; age of conceptus at vaccination; vaccination during the early embryonic, early fetal, and late fetal periods; and whether an early embryonic death (EED), e...
Sallé G, Cortet J, Koch C, Gascogne T, Reigner F, Cabaret J.Drug resistance in equine gastro-intestinal parasitic nematodes has been reported throughout the world. While the focus is usually put on cyathostomins, observations of macrocylic lactone failure against Oxyuris equi have accumulated over the last decade. Here we report the failure of ivermectin in the control of O. equi in an experimental Welsh pony herd. In a first trial, 6 ponies previously drenched with moxidectin and showing patent O. equi infections were administered ivermectin and subsequently monitored for O. equi egg excretion over one month. This trial demonstrated a failure of iverm...
Kweon CH, Kwon BJ, Ko YJ, Kenichi S.VP7, the sero-group common antigen, of African horsesickness virus (AHSV-4) was expressed in insect cells by recombinant baculovirus. To develop a specific diagnostic method, monoclonal antibody (Mab) against VP7 was prepared and investigated as diagnostic reagent with the baculovirus expressed VP7. However, the Mab against VP7 of AHSV cross-reacted with Chuzan virus by the indirect immunofluorescence assay (IFA), confirming the presence of conserved domain of VP7 among Orbiviruses. This study describes two types of ELISA; Mab linked indirect (I-ELISA) and competitive-ELISA (C-ELISA) using bac...
Singh BK, Ahuja S, Gulati BR.A single-dilution, sensitive and specific monoclonal antibody-based blocking enzyme-linked immunosorbent assay (B-ELISA) was developed as an alternative to the cumbersome virus neutralization test (VNT) for detection of equine herpesvirus-1 (EHV-1) antibodies. Neutralizing monoclonal antibodies (1H6 and 9C6) raised against EHV-1 (Hisar-90-7 strain) and sera from 70 horses (30 known negative and 40 known positive for EHV-1 antibodies by VNT) were used for standardization of the B-ELISA. Using a single serum dilution of 1:250 in B-ELISA, 100% specificity was obtained with both monoclonal antibod...
Debey MC, Bailie WE.Horse farms in Kansas were surveyed for the incidence of Rhodococcus equi. Fecal specimens and soil or cobweb samples were collected from each farm and cultured on selective media. One control farm (with no history of R. equi infection), one farm which had an outbreak 3 and 4 years previously and 2 farms which had R. equi-infected foals that season were surveyed. In addition, fecal samples from 21 horses hospitalized in the Kansas State University Veterinary Hospital were cultured. There was no significant difference in the incidence of R. equi in fecal samples from the 2 farms with recent dis...
Kubota T, Inaba Y, Uwatoko K, Akashi H, Fukunaga Y.Equine arteritis virus (EAV) grown on RK13 cell cultures was tested for hemagglutination (HA) with erythrocytes from a variety of species at 4 degrees C, room temperature and 37 degrees C. HA was observed at all temperatures with erythrocytes from mouse and chicken but not with those of cattle, horse, rabbit, guinea pig, mongolian gerbil, goose or chick embryo. Chickens showed an individual variation in agglutinability of their erythrocytes, requiring selection of birds to obtain erythrocytes for HA. The HA activity was enhanced by treatment of virus materials with Tween 80 followed by treatme...
Du Toit N, Gallagher J, Burden FA, Dixon PM.Dental disorders have recently been recognised as having major clinical and welfare implications in donkeys. However, no investigation appears to have examined the association of dental disorders with managemental factors and any intercurrent illness. Objective: To determine the association of dental disorders observed in a post mortem study with age group, body condition score, time since last dental treatment, feeding and the illness that necessitated euthanasia or caused death. Methods: A prospective study documented the type and prevalence of dental disorders in 349 mainly aged donkeys (me...
Müller I, Khanakah G, Kundi M, Stanek G.Grazing animals are continuously exposed to tick bites. Consequently, one may expect that horses will become infected with the various pathogens carried by ticks including Borrelia burgdorferi sensu lato. Whether horses may develop clinical disease due to this pathogen is controversially discussed. We were interested to learn about the infection of horses with Borrelia burgdorferi sensu lato within one season by studying the dynamics of the humoral immune response in paired blood samples. The majority of horses examined were Lipizzaner from the stud farm in Piber/Steiermark, and from the Spani...
Halliwell RE, Hines MT.A radioimmunoassay was developed for detection of immunoglobulin in the aqueous of normal horses and horses with intraocular diseases. Levels of albumin were detected by radial immunodiffusion. Results of assays on samples from normal eyes from which aqueous was obtained by paracentesis under anesthesia were 32.10 +/- 21.50 microgram/ml for IgG, 0.05 +/- 0.01 microgram/ml for IgM, 0.04 +/- 0.02 microgram/ml for IgA and 34.0 +/- 38.0 microgram/ml for albumin. Results in 138 normal eyes sampled post mortem were 41.56 +/- 38.65 microgram/ml for IgG, 0.18 +/- 0.43 microgram/ml for IgM, 0.46 +/- 1....
Davis SW, Speer CA, Dubey JP.Asexual stages of Sarcocystis neurona were seen in cultured bovine monocytes (M617) inoculated with tissue homogenates from the spinal cord of a horse with naturally acquired protozoal myelitis. Organisms first were observed as intracytoplasmic schizonts and later as motile extracellular zoites capable of infecting surrounding M617 cells. Parasites most often occurred as clusters of merozoites dispersed throughout the host cell cytoplasm; however, schizonts also contained merozoites arranged in a radial fashion surrounding a prominent residual body. Schizonts divided by endopolygeny. The paras...
Navas C, Manso T, Martins F, Minto L, Moreira R, Minozzo J, Antunes B, Vale A, McDaniel JR, Ippolito GC, Felicori LF.The antibody repertoire (Rep-seq) sequencing revolutionized the diversity of antigen B cell receptor studies, allowing deep and quantitative analysis to decipher the role of adaptive immunity in health and disease. Particularly, horse (Equus caballus) polyclonal antibodies have been produced and used since the century XIX to treat and prophylaxis diphtheria, tuberculosis, tetanus, pneumonia, and, more recently, COVID-19. However, our knowledge about the horse B cell receptors repertories is minimal. We present a deep horse antibody heavy chain repertoire (IGH) characterization of non-infected ...
Morgan RE, Clegg PD, Hunt JA, Innes JF, Tew SR.The joint synovium consists of a heterogeneous cell population, chiefly comprised of macrophages, and fibroblast-like synoviocytes (FLS). An inter-species co-culture model was developed to examine interactions between these cells. Equine FLS and the canine macrophage line DH82 were differentially labeled using fluorescent markers and results from direct co-culture compared with those from both indirect co-culture, and conditioned media experiments. The transcript expression of IL-1β, IL-6, ADAMTS4, and ADAMTS5 in each cell type were determined using species-specific qPCR assays. Lipopolysacch...
Pinna A, Martins G, Souza G, Lilenbaum W.The aim of this study was to demonstrate that seroreactivity against Leptospira is significantly associated to the reproductive efficiency of recipient mares of an embryo transfer (ET) programme. A serosurvey was conducted from August 2007 to March 2009 in five herds from Rio de Janeiro, Brazil, with high rates of reproductive failure, as early embryonic death (>12%), abortion (>12%) and perinatal death. Detailed information about the losses was obtained from practitioner. A total of 338 recipient mares were tested by microscopic agglutination test, and 226 (66.9%) were seroreactive, mainly ag...
Pal M.A total of 257 samples (from 51 cattle, 43 buffalo, 32 goats, 25 dogs, 23 horses, 14 fowl, 9 camels, 7 rabbits, 5 donkeys, 4 antelopes, 3 pigs, 2 monkeys, 1 bear and 38 humans, all with cutaneous disorders) were examined for the presence of Dermatophilus congolensis using standard microbiological techniques. Dermatophilus was identified in 14 specimens (5.45%) both by direct microscopy and by cultural isolation of the pathogen from cutaneous specimens. The infection was recorded in 2 humans, 6 cattle, 3 buffalo, 1 goat, 1 horse and 1 antelope. A history of trauma to the skin was evident in 6 o...
Yager JA, Duder CK, Prescott JF, Zink MC.Polymorphonuclear neutrophil leukocytes (PMNL) from 8 healthy foals (2-14 weeks of age) and 2 foals with bacterial pneumonia were separated from whole blood using a 2 step Percoll gradient. Purified PMNL were tested for bactericidal function against Rhodococcus equi and Staphylococcus aureus in the presence of normal horse serum. The percentage uptake after a 15-min pre-incubation of PMNL and bacteria was also calculated. Ultrastructural examination of the interaction of R. equi and normal foal PMNL was performed after 15 min incubation. Results indicated that foal PMNL effectively phagocytose...
Singh BR.Sixty-nine vaginal swabs and 138 rectal swabs collected from 195 equids were analysed for the presence of thermotolerant bacteria, that is, bacteria surviving at 60+/-0.1 degrees C for one hour. Thermotolerant Escherichia coli, Enterobacter species, Klebsiella pneumoniae, Proteus species and Pseudomonas species were isolated from 41, 16, nine, three and three of the 138 rectal swabs, respectively; seven of the E coli and two of the Enterobacter species isolates survived pasteurisation at 63.8+/-0.1 degrees C for 30 minutes. All except three E coli, two Enterobacter species and one Proteus spec...
Duarte PC, Conrad PA, Wilson WD, Ferraro GL, Packham AE, Bowers-Lepore J, Carpenter TE, Gardner IA.To estimate risk of exposure and age at first exposure to Sarcocystis neurona and Neospora hughesi and time to maternal antibody decay in foals. Methods: 484 Thoroughbred and Warmblood foals from 4 farms in California. Methods: Serum was collected before and after colostrum ingestion and at 3-month intervals thereafter. Samples were tested by use of the indirect fluorescent antibody test; cutoff titers were > or = 40 and > or = 160 for S neurona and N hughesi, respectively. Results: Risk of exposure to S neurona and N hughesi during the study were 8.2% and 3.1%, respectively. Annual rate...
Joncas JH, Gilker JC, Chagnon A.The relative value of heterophil agglutinins (HA) and of specific EBV antibodies in the diagnosis of infectious mononucleosis (IM) was assessed in 108 cases of the disease and in 280 controls. Among the 108 cases 93 were HA-positive by sheep cells in at least one of their sera, while 15 were HA-negative by the same test. Among the 280 controls false-positive HA tests were not encountered except in eight cases with the horse cell microtitre tests. With one of the two slide tests at least two false-positive tests and 12 false-negative tests were also found but these sera had low titres in microt...
Russell JW, Hall MS, Kelly GM.A 3-year-old Thoroughbred gelding was presented with a grade 3/5 lameness of the right forelimb and effusion of the extensor carpi radialis tendon sheath (ECRTS). Radiographic and ultrasonographic examinations revealed an osteochondroma on the cranial aspect of the distal radius projecting into the fibrous lining of the ECRTS. An open surgical approach was used to remove the osteochondroma and some of the proliferative synovial tissue. Conclusions: Six months after surgery the clinical signs had resolved and the horse raced successfully.
Sellers RF, Maarouf AR.Cases of western equine encephalitis in horses in 1987 in western USA and Manitoba, Canada were examined by backward trajectory analysis of winds. Culex tarsalis mosquitoes infected with western equine encephalitis virus could have been carried on southerly winds from Texas and Oklahoma to northern USA and from there to Manitoba. The presence of the Polar front over North Dakota and Minnesota at the end of July would have led to the landing of Cx. tarsalis in Montana and Wisconsin and prevented further carriage into Manitoba. Temperatures in southern Texas during the winter months (average dai...
Velineni S, Breathnach CC, Timoney JF.Streptococcus zooepidemicus (Sz) is a tonsillar commensal of healthy horses but with potential to opportunistically invade the lower respiratory tract. Sz is genetically variable and recombinogenic based on analysis of gene sequences including szp, szm and MLST data. Although a variety of serovars of the protective SzP are commonly harbored in the tonsils of the same horse, lower respiratory infections usually involve a single clone. Nevertheless, isolation of specific clones from epizootics of respiratory disease has been recently reported in horses and dogs in N. America, Europe and Asia. In...
Kaneko M, Oikawa M, Yoshihara T.Pathomorphological analysis was performed on fractured bones of 470 race horses. The most common fracture site was the limb (98% of cases), and the majority of fractures were intra-articular. Focal osteochondral lesions consisting of osteochondrosis, osteonecrosis and osteosclerosis were observed frequently in fractured and non-fractured bones. In the fractured bones, the lesions frequently appeared in the vicinity of the fractured site. Under the influence of antecedent osteochondrosis from the young stage, osteosclerotic and osteonecrotic lesions may have been induced by immoderate exercise ...
van Duijkeren E, van Klingeren B, Vulto AG, Sloet van Oldruitenborgh-Oosterbaan MM, Breukink HJ, van Miert AS.The in vitro activity of trimethoprim (TMP) and 9 sulfonamides and their combinations in 6 concentration ratios was tested against 62 Salmonella strains isolated from horses over a 3-year period in the Netherlands, using the agar-dilution method. Most of the isolates were S typhimurium strains (n = 52); the others were S heidelberg (n = 3), S hadar (n = 2), S thompson (n = 2), S enteritidis (n = 1), S infantis (n = 1), and S derby (n = 1). The minimal TMP concentration at which 50% of the Salmonella strains were inhibited (MIC50) was 0.12 micrograms/ml. Sulfachlorpyridazine (SCP; MIC50, 16 mic...
