Infections in horses encompass a range of diseases caused by various pathogens, including bacteria, viruses, fungi, and parasites. These infections can affect different systems within the horse, such as the respiratory, gastrointestinal, and integumentary systems, leading to a variety of clinical signs depending on the pathogen and the severity of the infection. Common infectious diseases in horses include equine influenza, strangles, and equine herpesvirus. Diagnosis often involves clinical examination, laboratory testing, and sometimes imaging, to identify the causative agent and assess the extent of the disease. Treatment strategies may include antimicrobial therapy, supportive care, and preventive measures such as vaccination and biosecurity practices. This page aggregates peer-reviewed research studies and scholarly articles that explore the pathogenesis, diagnosis, treatment, and prevention of infectious diseases in equine populations.
Fenger CK, Granstrom DE, Langemeier JL, Stamper S.To determine the clinical findings, course of treatment, and long-term outcome of horses on a farm in central Kentucky during an epizootic of equine protozoal myeloencephalitis (EPM). Methods: Cohort study. Methods: 21 horses on a farm in central Kentucky, 12 of which developed clinical signs of EPM. Methods: Horses on the farm were serially examined for signs of neurologic disease and serum and CSF antibodies to Sarcocystis neurona. Horses were considered to have EPM if they had neurologic signs and positive test results for antibodies to S neurona in CSF. Blood values were monitored for evid...
Grassmann B, Kopp PA, Schmitt M, Blobel H.Adherence of 4 Borrelia (B.) burgdorferi strains (z7/22, z7/27, z7/41, PBi) to polymorphonuclear granulocytes from different domestic animals (horses, cattle, sheep, dogs) was investigated. All 4 strains adhered to the granulocytes. Binding assays indicated that the adherence occurred between structures on the surface of the borreliae ("binding-sites") and on the membranes of the granulocytes ("receptors"). The "receptors" consisted of 4 fractions (A, B, C, and D) with components differing in molecular weight (MW) and binding activity for proteins on the surface of B. burgdorferi. Fraction A (...
Whitlock RH, Buckley C.Equine botulism is being recognized with increasing frequency by veterinarians throughout North America. Muscular weakness and dysphagia that progress during a period of 1 to 4 days, in the absence of laboratory derangements that indicate the presence of systemic disease, are suggestive of botulism. A tentative diagnosis usually is based on the presence of the following findings on physical examination: delayed pupillary light response, mydriasis, ptosis, generalized weakness, decreased tail tone, and slow prehension of feed. Definitive diagnosis requires detection of botulinum toxin in plasma...
Zheng YH, Nakaya T, Sentsui H, Kameoka M, Kishi M, Hagiwara K, Takahashi H, Kono Y, Ikuta K.We have studied a horse which exhibited typical clinical signs of disease when experimentally infected with a non-adapted virulent strain of equine infectious anaemia virus (EIAV), designated V70. Five viruses (F1V, F2V, F3V, F4V and F5V) were recovered during periodic febrile episodes. Cross-neutralization tests revealed that all of these variants and the parental V70 were antigenically distinct. Sequencing of their full-length env gp90 genes and gp45 5' sequences revealed novel mutations at a limited number of nucleotide positions, consisting of insertions and duplications in the gp90 princi...
Sutton GA, Viel L, Carman PS, Boag BL.The purpose of this experiment was to study the duration and distribution of equine influenza virus in actively infected ponies over a 3 wk period. Pony foals (6-8 mo old) were infected experimentally by nebulizing equine influenza subtype-2 virus ultrasonically through a face mask. Successful infection was clinically apparent as each of the foals (n = 6) had a febrile response, a deep hacking cough and mucopurulent nasal discharge for 7 to 10 d. The virus was isolated from nasopharyngeal swabs of all the ponies 3 and 5 d after infection and all the ponies seroconverted to the virus. Samples w...
Nagy E, Idamakanti N, Carman S.Ninety-two equine herpesvirus type 1 isolates were recovered from aborted, stillborn, or neonatal foals from Ontario, Canada, from 1986 to 1992. From this total, 32 strains were randomly chosen for further study. Four or 5 isolates from each winter were selected, each from a different premises, and characterized by restriction enzyme analysis using BamHI, KpnI, BglII, HindIII, and EcoRI. Additional isolates from 2 premises and from a zebra foal were also assessed. For the strains isolated in 1986 and 1989-1992, the DNA pattern of 18 strains was similar to that of type 1P (Kentucky D) for BamHI...
Charan S, Palmer K, Chester P, Mire-Sluis AR, Meager A, Edington N.Up to 21 days after exposure to live or ultraviolet-inactivated equid herpesvirus type-1 (EHV-1) autologous serum from ponies caused an immunosuppressive effect if incorporated into T-cell proliferation assays to EHV-1. The suppressive factor in the sera of ponies also inhibited T-cell response to phytohaemagglutinin. Increased levels of circulating activated transforming growth factor-beta 1 (TGF-beta 1) were detected, and the suppressive activity of the serum could be reversed by antibody to TGF-beta 1. In a challenge experiment the ponies which exhibited circulating TGF-beta 1 activity succ...
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...
Geerts S, Coles GC, Gryseels B.During the past decade, the prevalence of anthelmintic resistance in some economically important helminths of sheep, goats and horses has increased dramatically. In some regions of Australia, South America and South Africa, anthelmintic resistance has become a serious threat to the survival of the sheep industry. Mass treatment programmes and exclusive reliance on anthelmintics for worm control in livestock are amongst the most important reasons for the development of anthelmintic resistance. In this article, Stanny Geerts, Gerald Coles and Bruno Gryseels draw the attention to a number of erro...
Griffiths NJ, Walton JR, Edwards GB.Equine anterior enteritis is an acute syndrome with unknown aetiology, although salmonellosis and infection with Clostridium perfringens have both been suggested as potential causes. The main aim of this preliminary study was to compare the prevalence of toxigenic types of C. perfringens in clinically healthy horses and in horses with anterior enteritis. From horses admitted with colic at Phillip Leverhulme Large Animal Hospital in 1995-1996, samples of gastric reflux, small intestinal contents and faeces were taken for isolation of C. perfringens. Five of those horses were admitted as anterio...
Prescott JF, Nicholson VM, Patterson MC, Zandona Meleiro MC, Caterino de Araujo A, Yager JA, Holmes MA.To evaluate use of the virulence-associated protein of Rhodococcus equi in immunizing foals against R equi pneumonia. Methods: Eight (experimental group) and 6 (controls) mares with their foals. Methods: Virulence-associated protein extracted from R equi was used to prepare an acetone-precipitated. Triton X-extracted (APTX) antigen. After determination of the efficacy of passive immunization, in untreated foals or in foals given plasma from a horse vaccinated with APTX antigen or from a nonvaccinated horse, a field trial was done to evaluate the efficacy of vaccination of 8 mares, twice with A...
Blay KL, Gueirard P, Guiso N, Chaby R.Six monoclonal antibodies (mAbs) against lipopolysaccharides (LPS) from Bordetella pertussis (P1P3, 60.5), B. parapertussis (PP2, PP6, PPB) and B. bronchiseptica (BRg1) were used to examine the presence of antigenic determinants of LPS on B. bronchiseptica cells. Forty-eight clinical isolates of this Gram-negative bacterium (4 canine, 3 equine, 6 porcine, 4 rabbit and 31 human) were examined. Significant cross-reactivities with the heterologous anti-pertussis and anti-parapertussis mAbs were observed. The isolates also exhibited marked antigenic polymorphism. The 48 isolates could be classifie...
Watson ED.Outbreaks of contagious equine metritis in Britain during 1996 emphasised the importance of preventing the disease through full and widespread implementation of the Horserace Betting Levy Board's code of practice. The provision of satisfactory samples for testing represents an integral part of applying the code. Here, in an article commissioned by the British Equine Veterinary Association, Dr Elaine Watson describes the techniques involved.
Geelen SN, Bernadina WE, Grinwis GC, Kalsbeek HC.A 15-year-old Dutch warmblood mare was presented because of lethargy, which had been present for several weeks, and severe anaemia. Total protein was high and serum electrophoresis revealed a monoclonal peak in the alpha-2 region. Monoclonal immunoglobulin, IgG(T), was detected by immuno-electrophoresis in serum and urine. Postmortem examination revealed a relatively large number of plasmacytoid cells in the bone marrow and a monotonous population of plasmacytoid cells in the spleen. These findings are suggestive of a plasma cell myeloma.
Hilbe M, Meier D, Feige K.This article describes an eleven year old mare with apathy, fever, enlarged mandibular lymph nodes, skin lesions on the upper lip and edematous, grey-red mucous membranes in the nose, mouth and vulva. Histopathology revealed infiltrates with atypical lymphocytes forming Pautrier's microabscesses. The neoplastic cells had large, often indented nuclei. Immunohistology showed that some cells were CD3-positive (Pan T-cell-marker). The diagnosis of cutaneous epitheliotropic malignant lymphoma (Mycosis fungoides) was made. The etiology in the horse is unknown.
Barlough JE, Rikihisa Y, Madigan JE.A nested polymerase chain reaction was developed for amplifying a 529-bp segment of the 16S ribosomal RNA gene of Ehrlichia risticii from equine buffy coat cells. Confirmation of identity of the amplified bands was accomplished by Southern hybridization and DNA sequencing. The study indicated a detection limit of > 10 copies of the target gene, and specificity for E. risticii as based on a panel of test rickettsiae. Ticks (Ixodes pacificus) collected in an area of northern California enzootic for equine monocytic ehrlichiosis were found to be negative for E. risticii DNA.
Basher AW, Severin GA, Chavkin MJ, Frank AA.Three horses were examined because of exophthalmos and others signs indicative of a space-occupying orbital mass. In 2 horses, exenteration was used to remove the orbital mass. In a third horse, an orbital tumor and lung metastases were found at necropsy. Routine histologic and Grimelius' histochemical staining were used on fixed tissues; immunohistochemical staining for chromogranin and electron microscopy also were performed. Masses were orbital neuroendocrine tumors. Horses that underwent exenteration were alive 19 and 24 months after surgery. Hypotension was encountered at surgery in both ...
Thomas PG, Ball BA, Ignotz GG, Dobrinski I, Parks JE, Currie WB.Before fertilization, equine spermatozoa adhere to oviduct epithelial cells (OEC) of the mare. The biochemical basis for this adhesion has not been determined. Our objective was to produce an antiserum to block this interaction. Ejaculated spermatozoa were subjected to nitrogen cavitation and spermatozoal plasma membranes enriched by sucrose density gradient centrifugation; membrane enrichment was confirmed by comparative alkaline phosphatase analysis, electron microscopy, and one- and two-dimensional PAGE. Periacrosomal plasma membrane was used as an immunogen for the production of an antiser...
Paweska JT.Eight sexually mature horse stallions were inoculated intranasally with a South African asinine strain of EAV, a strain that was isolated from the semen of a donkey carrier. All horses developed fever, with maximum rectal temperatures of 38.9-39.9 degrees C recorded 3-6 d post challenge. Six horses showed very mild clinical signs of equine viral arteritis and two were asymptomatic. The virus was recovered from the nasopharynxes of six horses 2-7 d after inoculation, and from buffy-coat samples of all horses, 2-11 d after inoculation. Seroconversion to EAV was detected on days 8 and 10 and peak...
Schlichtherle C.This paper describes the importance of fumonisins for human beings and animals and shows data for the occurence in food. Corn-based food samples (n = 299) purchased in the area of munich were analyzed for fumonisin content using an enzyme immunoassay.Fumonisins are mycotoxins produced byFusarium species, especially byFusarium moniliforme andFusarium proliferatum. Occurrence of fumonisins in corn and in cornbased foods and feeds has been reported from almost all over the world. In several animal species different diseases are traced back to fumonisin toxicosis. Fumonisin levels of 5-10 ppm inho...
Olson ME, Thorlakson CL, Deselliers L, Morck DW, McAllister TA.Giardia intestinalis and Cryptosporidium spp. are commonly identified intestinal pathogens in humans and animals. In light of the clinical disease, production losses and zoonotic potential of both Giardia and Cryptosporidium infections, a study was undertaken to investigate the prevalence of these parasites in cattle, sheep, pigs and horses in Canadian farms at different geographical locations. A total of 104 cattle, 89 sheep, 236 pigs and 35 horses were sampled from 15 different Canadian geographical locations. Fecal samples were examined after concentration and immunofluorescent staining. Gi...
Hague BA, Honnas CM, Simpson RB, Peloso JG.This study evaluates skin bacterial flora before and after aseptic preparation of clipped and nonclipped arthrocentesis sites in horses. Methods: The hair over one midcarpal joint and one distal interphalangeal joint on each horse was clipped. The contralateral joint served as the nonclipped comparison. Methods: Twelve adult horses. Methods: A prescrub sample for microbial culture was taken from the dorsal surface of all four joints for each horse. Each site was aseptically prepared with povidone iodine and 70% alcohol, followed by postscrub sampling for microbial culture. Colony forming units...
Zweygarth E, Just MC, De Waal DT.By means of an in vitro culture technique, 75 samples of horse blood were examined for Babesia equi, a causative agent of equine piroplasmosis. At the time of culture initiation, 15 samples were microscopically positive for B. equi, and this was subsequently confirmed by culture diagnosis. Sixty samples showed no parasites in Giemsa-stained thin blood smears. However, after the culturing process, parasites were found in blood smears of 36 of these samples. The sensitivity of the in vitro culture method was such that 2.5 microliters (1/40 of the usual volume used for the above-mentioned samples...
Escande F, Vallee E, Aubart F.The isolation of Pasteurella caballi from an horse-bite wound in a 56-year-old man is reported. Biochemical characteristics are described and compared with the other species representing the genus Pasteurella. This strain probably represents the first human isolate of P. caballi in France.
Fenger CK, Granstrom DE, Gajadhar AA, Williams NM, McCrillis SA, Stamper S, Langemeier JL, Dubey JP.Sarcocystis sp. sporocysts isolated from eight feral opossums (Didelphis virginiana) were pooled and fed to 18 commercially reared budgerigars (Melopsittacus undulatus), 14 wild-caught sparrows (Passer domesticus), one wild-caught slate-colored Junco (Junco hyemalis) and five weanling horses (Equus caballus). All budgerigars died within 5 weeks post inoculation (wpi). Histologic examination revealed meronts within the pulmonary epithelia and typical Sarcocystis falcatula sarcocysts developing in the leg muscles. Sparrows were euthanized 13 and 17 wpi and their carcasses were fed to four labora...
Martínez-Torrecuadrada JL, Díaz-Laviada M, Roy P, Sánchez C, Vela C, Sánchez-Vizcaíno JM, Casal JI.Fifteen horses were experimentally infected with African horse sickness virus (AHSV) serotype 4. To learn more about the time course of production and specificity of AHSV-specific antibodies, sera were analyzed by immunoblot analysis. Only animals that survived for more than 9 days were able to develop a humoral immune response detectable by immunoblotting. The earliest serological markers corresponded mainly to VP5, VP6, and NS2 and to a lesser extent to VP3, NS1, and NS3. Neutralizing antibodies to VP2 were not detected by immunoblotting, suggesting that they are mostly conformation dependen...
Blue JT, Dinsmore RP, Anderson KL.Three horses developed severe, immune-mediated hemolytic anemia after treatment with penicillin. The horses had positive direct antiglobulin (Coombs) tests and high titers of IgG antibody that agglutinated penicillin-coated equine red cells. Two of the horses were tested for antibodies to autologous red cell antigens; autoantibodies were not present. Titers of antipenicillin antibody decreased after penicillin was discontinued but IgG antibody was detectable months after recovery. One of the horses was challenged with penicillin; antibody titer increased slightly, but anemia did not develop. A...
Watkins JP, Taylor TS, Schumacher J, Taylor JR, Gillis JP.The records of 35 horses with Grade 3 or 4 rectal tears, presented to the Veterinary Medical Center at Texas A & M University over a five year period, were reviewed. Grade 3 tears were sub-classified according to whether the remaining tissue was serosa (Grade 3a) or mesorectum (Grade 3b). Five horses were destroyed on presentation and 30 were treated by primary suture closure (8 horses), faecal diversion alone (9 horses) or in combination with suture closure (11 horses) and packing of the tear with medicated gauze sponges (two horses). Faecal diversion was achieved with a temporary indwell...
Boudreaux MK, Humphries DM.Platelet alloantigens in horses may play an important role in the development of neonatal alloimmune thrombocytopenia (NAIT). Objective: The objective of this study was to evaluate genes encoding major platelet glycoproteins within the Equidae family in an effort to identify potential alloantigens. Methods: DNA was isolated from blood samples obtained from Equidae family members, including a Holsteiner-Oldenburg cross, a Quarter horse, a donkey, and a Plains zebra (Equus burchelli). Gene sequences encoding equine platelet membrane glycoproteins IIb, IIIa (integrin subunits αIIb and β3), Ia (...
Wernery U, Chan E, Raghavan R, Teng JLL, Syriac G, Siu SY, Joseph M, Yeung ML, Jia L, Cai JP, Chiu TH, Lau SKP, Woo PCY.Glanders is a highly contagious and potentially serious disease caused by Burkholderia mallei, a Tier 1 select agent. In this study, we raised a monoclonal antibody (mAb) against the lipopolysaccharide (LPS) of B. mallei and developed a competitive enzyme-linked immunosorbent assay (cELISA) for B. mallei infection. Using the titrated optimal conditions of B. mallei-LPS (2 ng) for microtiter plate coating, sample serum dilution at 1:20 and 3.5 ng/μL anti-LPS mAb B5, the cutoff value of the cELISA was determined using serum samples from 136 glanders-free seronegative horses in Hong Kong. All ca...
Hardy J.Careful planning and design of a new ICU are warranted to maximize use of the facility, minimize the risk of hospital-acquired infection, and improve overall patient outcome. In addition, personnel satisfaction improves with an improved work environment. A functional equine ICU is also tailored to the geographic area, local needs of the practice, and anticipated investment.
Friedlander M, Sobotka H, Banzhaf EJ.The precipitin indices for a number of monovalent and polyvalent antipneumococcus sera were determined under known conditions, and found to vary as did the number of protective units. The ratio precipitin index/protective units in monovalent sera was found to lie between 2.8 and 4.8 for Type I and to be about ten times greater for Type III. Lower values were found in polyvalent horses and when mixing heterologous monovalent sera with each other. The influence of the duration of treatment upon the quotient was studied. Several refined and concentrated preparations showed a relative increase in ...
Sharma D, Gupta S, Sethi K, Kumar S, Kumar R.Trypanosoma evansi, a hemoflagellate protozoan parasite, causes wasting disease called surra in wide range of animals. Although the organism has been reported from various parts of India, data generated from organized epidemiological study is still in infancy in majority states of India. In the present study, livestock of Himachal Pradesh, India, was targeted for epidemiological investigation of T. evansi infections. A total of 440 equines and 444 cattle serum samples were collected from four agro-climatic zones. Furthermore, serum samples of 280 buffaloes from three different agro-climatic zo...
Majeed QA, Alazemi MS, Henedi AA, Tahrani LM.No doubt, farm animals are essential as a source of milk, protein, and leather and wool ... etc. But, they are always exposed to ecto- and endo-parasites, which cause diseases conditions that may end in death. This study evaluated farm animal parasitosis. Thus, different animal farms were visited to collect fecal samples and data to determine the infection rates with parasites and the relationship between animal management and parasitism in Kuwait. Out of 86, 17, 20, 96 & 52 cattle, sheep, goats, horses and camels examined, 5.5, 17.5, 10, 9.3 and 2.5% respectively were infected with differ...
Epe C, Kings M, Stoye M, Böer M.Wild equids maintained in large enclosures may suffer from helminth diseases because common hygiene practices have only limited effects on parasite populations. Weekly monitoring of helminth prevalences and pasture infestation was performed for 1 yr in several extensive maintenance systems of two wildlife parks with similar climates to determine when veterinary intervention to control parasites would be useful. We also sought evidence of natural immunogenic reactions among herds of Chapman zebras (Equus quagga antiquorum), Przewalski's horses (Equus przewalskii) and dwarf donkeys (Equus asinus...
Schvartz G, Epp T, Burgess HJ, Chilton NB, Pearl DL, Lohmann KL.Equine granulocytic anaplasmosis (EGA) and Lyme borreliosis (LB) are an emerging concern in Canada. We estimated the seroprevalence of EGA and equine LB by testing 376 convenience serum samples from 3 provinces using a point-of-care SNAP(®) 4Dx(®) ELISA (IDEXX Laboratories, Westbrook, Maine, USA), and investigated the agreement between the point-of-care ELISA and laboratory-based serologic tests. The estimated seroprevalence for EGA was 0.53% overall (0.49% in Saskatchewan, 0.71% in Manitoba), while the estimated seroprevalence for LB was 1.6% overall (0.49% in Saskatchewan, 2.86% in Manitob...
Kagawa S, Moore JE, Murayama O, Matsuda M.Eight strains of Taylorella equigenitalis were identified by a polymerase chain reaction using a primer pair specific to the 16S rDNA of T equigenitalis. These eight strains were chosen because they had previously been shown to represent eight distinct genotypes by pulsed-field gel electrophoresis analysis after separate digestion of the genomic DNA with ApaI or NotI. The eight strains could be classified into six or seven types by random amplified polymorphic DNA analysis using different kinds of primers. Amplified rDNA restriction analysis after separate digestion with five restriction enzym...
Al-Mokaddem AK, Ahmed KA, Doghaim RE.Donkeys (Equus africanus asinus) are important working animals, particularly in countries where the majority of the population lives below the poverty line. Gastric ulceration has been shown to be common in British donkeys but donkeys from other parts of the world have not been as extensively researched. Objective: This study was performed as a preliminary overview of the severity and distribution of gastric lesions in mature donkeys and to document which parasites were present. Methods: Descriptive study of pathological findings. Methods: Stomachs of 35 mature draught donkeys were examined gr...
Sánchez-Matamoros A, Nieto-Pelegrín E, Beck C, Rivera-Arroyo B, Lecollinet S, Sailleau C, Zientara S, Sánchez-Vizcaíno JM.African horse sickness (AHS) is considered a fatal re-emergent vector-borne disease of horses. In the absence of any effective treatment for AHS, vaccination remains the most effective form of disease control. The new generation of vaccines, such as one based on purified, inactivated AHS virus (AHSV, serotype 4), which does not induce antibodies against non-structural protein 3 (NS3), enables the development of diagnostic methods that differentiate infected from vaccinated animals (DIVA assays). As detecting AHS in AHSV-free countries may lead to restrictions on international animal movements ...
Knight AP.Dysphagia developed in a 2-year-old Quarter Horse filly following an incident in which it fell over backward while exercising on a mechanical horse walker. Hyperextension of the neck at this time apparently caused unilateral rupture of the longus capitis (rectus capitis ventralis major) and the rectus capitis ventralis minor muscles at their insertion. An existing mycotic lesion involving the dorsomedial wall of the left guttural pouch may have weakened the area of insertion of the involved muscles. Tearing of the tendinous insertion of these muscles caused damage to the IX, X, and XI cranial ...
Pezzanite LM, Hendrickson DA, Dow S, Stoneback J, Chow L, Krause D, Goodrich L.Antibiotics have been injected intra-articularly by equine veterinarians for decades, either prophylactically when other drugs are administered for osteoarthritis or therapeutically to treat septic arthritis. This route of administration has also more recently gained attention in human orthopaedic clinical practice, particularly as an alternative to systemic antibiotic administration to treat infections following prosthetic arthroplasty. While the rationale for injecting antibiotics intra-articularly has been largely focused on achieving high local drug concentrations, there has been relativel...
Hansen PJ, Hoggard MP, Rathwell AC.The ability of stallion seminal plasma to modify phagocytosis of spermatozoa and Streptococcus zooepidemicus was examined. Phagocytosis was monitored indirectly as the H2O2 produced by peripheral blood leukocytes after addition of spermatozoa or bacteria. Hydrogen peroxide production after addition of ejaculated spermatozoa was greater (P less than 0.01) than after addition of epididymal sperm. Furthermore, pre-incubation of epididymal sperm with 6.25-50% seminal plasma caused a dose-dependent increase in subsequent H2O2 production by leukocytes (P less than 0.05). In addition, equine serum wa...
Sebastian MM, Stewart I, Williams NM, Poonacha KB, Sells SF, Vickers ML, Harrison LR.Pathological, entomological and avian investigations were conducted during the summer of 2002, in a horse farm that had four cases of West Nile virus (WNV) infection in horses. All the four horses had encephalitis and WNV infection was confirmed by RT-PCR and in situ hybridization procedure. Forty-seven per cent of house sparrows that resided on the farm were tested positive for WNV infection. Mosquitoes (98%Culex pipiens) collected by trapping at the farm, during this period were positive for WNV. The meteorological data for year 2002 were compared to previous 16 years. The precipitation and ...
Dagleish MP, Brazil TJ, Scudamore CL.Lipopolysaccharide (LPS) and N-formyl-methionyl-leucyl-phenylalanine (fMLP)-like peptides are Gram-negative bacterial cell wall components which, when released into the peripheral circulation in endotoxaemia, have the potential to activate leucocytes. In vitro, equine neutrophils require priming with LPS in order to generate reactive oxygen intermediates (ROI) in response to fMLP. Objective: The aim of this study was to examine whether the release of other neutrophil products is similarly dependent on prior priming with LPS. In particular, neutrophil elastase (NE), a potent proteolytic enzyme,...
Slovis NM, Watson JL, Couto SS.A 6-month-old Morgan colt was evaluated because of a 10-cm right-sided retropharyngeal swelling. The swelling was soft and moveable on examination, and palpation did not elicit signs of pain. Radiography revealed a large space-occupying mass ventral to the second cervical vertebra; ultrasonography revealed an anechoic fluid-filled structure with a well-defined hyperechoic capsule. Fine-needle aspiration yielded a viscous amber fluid. Cytologic evaluation indicated that the fluid was an exudate; anaerobic and aerobic bacterial culture did not yield any growth. Histologic examination of a portio...
Caron JP, Fretz PB, Bailey JV, Barber SM, Hurtig MB.Epistaxis, caused by guttural pouch mycosis, was treated by balloon-tipped catheter and ligature occlusion of the involved arteries in 13 horses. In 7 horses, more than one artery was catheterized. Serious postoperative hemorrhage was prevented in all horses. Long-term endoscopic follow-up examination was possible in 8 horses, and all had complete regression of the fungal lesion as early as 5 weeks after surgery. Six of the 8 horses did not receive medical treatment. Problems related to the use of the balloon-tipped catheter technique were rare. There were incisional infections in 3 horses, ca...
Liu Q, Ma J, Wang XF, Xiao F, Li LJ, Zhang JE, Lin YZ, Du C, He XJ, Wang X, Zhou JH.The live equine infectious anemia virus (EIAV) vaccine strain EIAVDLV121 was developed by in vitro attenuation of a virulent strain, EIAVLN40, in the 1970s, and it has been demonstrated to induce protective immunity under laboratory and natural EIAV infection conditions. The detailed biological features of this attenuated virus remain to be further investigated. Experimental inoculation with EIAVDLV121 did not result in clinical symptoms even with immunosuppressive treatment in our previous studies. Here, we further investigated whether the replication of the vaccine strain EIAVDLV121 in exper...
Ata EB, Zaghawa A, Ghazy AA, Elsify A, Abdelrahman K, Kasem S, Nayel M.Equine herpesvirus-1 (EHV-1) is an important pathogen, which infects horses worldwide with high morbidity but low mortality rates. The respiratory disorders and abortions are the most common indicators. Ab4p (an abortigenic and paralytic virus) is one of the most important and virulent strains. The development and functional characterization of the open reading frame-68 (ORF68) negative EHV-1 Ab4p mutants and an assessment of their roles in the infection at the cellular level were the main targets of the current study. Escherichia coli DH10β containing the Ab4p bacterial artificial chromosome...
Durando MM, Birks EK, Hussey SB, Lunn DP.Myocarditis is thought to occur secondary to equine influenza virus (EIV) infections in horses, but there is a lack of published evidence. Objective: We proposed that EIV challenge infection in ponies would cause myocardial damage, detectable by increases in plasma cardiac troponin I (cTnI) concentrations. Methods: Twenty-nine influenza-naïve yearling ponies: 23 were part of an influenza vaccine study (11 unvaccinated and 12 vaccinated), and were challenged with 10⁸ EID₅₀ EIV A/eq/Kentucky/91 6 months after vaccination. Six age-matched healthy and unvaccinated ponies concurrently housed...
Tallmadge RL, Stokol T, Gould-Earley MJ, Earley E, Secor EJ, Matychak MB, Felippe MJ.Fell Pony syndrome (FPS) is a fatal immunodeficiency that occurs in foals of the Fell Pony breed. Affected foals present with severe anemia, B cell lymphopenia, and opportunistic infections. Our objective was to conduct a prospective study of potential FPS-affected Fell Pony foals to establish clinical, immunological, and molecular parameters at birth and in the first few weeks of life. Complete blood counts, peripheral blood lymphocyte phenotyping, and serum immunoglobulin concentrations were determined for 3 FPS-affected foals, 49 unaffected foals, and 6 adult horses. In addition, cytology o...
Morris DD, Whitlock RH.Equine antiserum to core lipopolysaccharide (LPS) was evaluated in a double-blind prospective study for therapeutic benefit in suspected septicemia in neonatal foals. Forty foals younger than 7 days of age were included in the study by satisfaction of clinical and laboratory criteria, suggestive of gram-negative septicemia. Twenty-two foals were treated with core LPS antiserum (plasma produced from horses which were hyperimmunized with rough gram-negative mutant bacterin) and 18 foals received "nonimmune" plasma (from horses prior to immunization against core LPS). All foals received antimicro...
Reinemeyer CR, Hutchens DE, Eckblad WP, Marchiondo AA, Shugart JI.Dose confirmation studies of the cestocidal activity of pyrantel pamoate paste were conducted at two sites in North America during 2001. Horses with naturally-acquired cestode infections were identified by detection of typical Anoplocephala spp. eggs in feces collected between 7 and 92 days prior to treatment. Twenty and 22 horses were enrolled at Site 1 (Urbana, IL) and Site 2 (Knoxville, TN), respectively. Candidate horses were acclimated to study conditions for 14 days, ranked by length of interval since coprologic confirmation, and allocated randomly to one of two treatment groups: (T1) py...
Abo-Aziza FAM, Hendawy SHM, Abdullah HHAM, El Namaky A, Laidoudi Y, Mediannikov O.Equine filariosis (EF) is a neglected vector-borne disease caused by nematode species belonging to the Onchocercidae and Setariidae families. Aside from their zoonotic potential, some species are responsible for serious health problems in equids worldwide, leading to significant economic difficulties. Here, we molecularly investigated equine blood samples (320 horses and 109 donkeys from Egypt) and four adult worms isolated from the peritoneal cavity of 5 out of the 94 slaughtered donkeys. In addition, quantitative enzyme-linked immunoassays (ELISAs) targeting circulating cytokines were used t...
Ponce Gordo F, Cuesta Bandera C.The Spanish sheep and horse strains of Echinococcus granulosus possess several differential characteristics in their metacestode stage. Cysts from sheep vary widely in size and fertility, but they usually have a thin cyst wall and, when fertile, a whitish hydatid sand formed by brood capsules and protoscoleces. Two types of infections have been observed in horses: one resembling that of sheep, caused by small, non-fertile cysts with a thin wall, and a second type caused by medium to large, always fertile cysts with a thick wall. In this latter case, hydatid sand is always dark brown in color a...
Ramzan PH.Removal of cheek teeth in all but the aged horse or pony is a serious undertaking with potentially deleterious sequellae. Rigid endoscopy permits detailed examination of the oral cavity and erupted dental tissues and has the potential to assist in the correct identification of the diseased tooth. Objective: To document oral endoscopic findings associated with infected equine cheek teeth in cases without gross oral pathological changes and thereby determine the usefulness of rigid oral endoscopy as an aid to diagnosis of such infections. Methods: Records of all cases of equine cheek tooth remov...
Badenhorst M, Saalmüller A, Daly JM, Ertl R, Stadler M, Puff C, de le Roi M, Baumgärtner W, Engelmann M, Brandner S, Junge HK, Pratscher B, Volz A....Equine hepacivirus (EqHV) is the closest known genetic homologue of hepatitis C virus. An effective prophylactic vaccine is currently not available for either of these hepaciviruses. The equine as potential surrogate model for hepacivirus vaccine studies was investigated, while equine host responses following vaccination with EqHV E2 recombinant protein and subsequent EqHV inoculation were elucidated. Four ponies received prime and booster vaccinations (recombinant protein, adjuvant) four weeks apart (day -55 and -27). Two control ponies received adjuvant only. Ponies were inoculated with EqHV...
