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.
Shane BS, Issel CJ, Montelaro RC.A sensitive specific enzyme-linked immunosorbent assay utilizing purified p26 antigen was developed for the detection of antibodies to equine infectious anemia virus in naturally and experimentally infected horses. Generally, antibodies to the virus could be detected by the enzyme-linked immunosorbent assay 3 to 4 days earlier than by the standard agar gel immunodiffusion test, and they could be detected more reliably in horses with weak or equivocal agar gel immunodiffusion test reactions. The enzyme-linked immunosorbent assay was also successfully applied to the detection of p26 antigen in t...
Houston RS, Craig TM, Fincher GT.Effects on the recently introduced dung-burying beetle, Onthophagus gazella F, on free-living stages of equine strongyles were determined on a Texas pasture. Two populations of O gazella (22 and 44 pairs) were exposed to 1-kg deposits of equine dung containing 545,000 strongyle eggs for 31 days near the end of the beetle's activity season. Weekly dung and pasture samples were taken from these plots and from control plots from which beetles were excluded to recover developing larvae. Significant differences did not occur among the 3 treatments (P less than 0.05).
Townley P, Baker KP, Quinn PJ.An investigation of the landing and engorging sites of midges on a bait horse was made in Ireland as part of a project examining the aetiology of sweet itch. Ten species were recovered, seven of which engorged. Culicoides obsoletus and C dewulfi were the most commonly represented, accounting for 89.9 per cent of midges landing and 90.5 per cent of midges engorging. Only 4.69 per cent of midges attracted to the bait were C pulicaris. Overall, the preferential landing sites for midges were along the mane and lower leg regions. Few culicoides were attracted to the head, front and underside of the...
Pellegrini A, Von Fellenberg R.A new and probably unique elastase inhibitor of horse serum was identified, purified to homogeneity and called pre-alpha 2-elastase inhibitor of the horse. Electrophoretically it migrated immediately in front of the alpha 2 position. Its molecular weight was 188 000 by pore limit polyacrylamide gel electrophoresis and 225 000 by Sephadex G-200 gel filtration. The inhibitor was composed of at least two non-identical polypeptide chains of Mr 68 400 and 87 600. A banding pattern of restricted heterogeneity focused between pH 4.9 and 5.2 was revealed by isoelectric focusing. Of 13 animal, microbia...
Van Heerden J, Reyers F.The clinical signs, response to treatment and features of the spirochaete, Borrelia theileri as was found in a horse with suspected borreliasis are described.
Geiser DR, Walker RD.The pathophysiology and histopathology of thermal burns in large animals is very similar to that in humans. Burns are classified as first degree, superficial and deep second degree, third degree, and fourth degree, depending upon the depth of thermal injury. Most severe burns will produce a local and a systemic response--both of which must be properly treated to increase the patient's chances for survival. The systemic response is mainly characterized by hypovolemia, fluid and electrolyte loss, protein loss, pulmonary edema, increased caloric requirements, and depressed immune responses. The l...
Polley L.In an abattoir survey of 383 horses from the four western provinces of Canada and 240 horses from Washington, Montana and North Dakota prevalences of Onchocerca sp of 11.8% and 25.8% respectively have been demonstrated by umbilical skin specimen examinations. The results of this survey are discussed in relation to the parasite's natural history and its clinical significance in western Canada.
Prescott JF, Nicholson VM.The minimal inhibitory concentrations of penicillin G, ampicillin, gentamicin, erythromycin and rifampicin were determined for nine strains of Corynebacterium equi. The effect of combinations of any two of these antibiotics on the killing of these strains was determined at antibiotic concentrations achievable in horses using recommended drug dosages (ampicillin 4.0 microgram/ml, gentamicin 1.0 microgram/ml using recommended drug dosages (ampicillin 4.0 microgram/ml, gentamicin 1.0 microgram/ml and erythromycin 0.25 microgram/ml). Penicillin G was used at 4.0 microgram/ml and rifampicin at 0.06...
McGavin MD, Fadok VA.Skin biopsy for histologic, immunofluorescent, parasitologic, and bacteriologic examination is a common procedure, but for maximum effectiveness the clinician must realize the importance of precautions to select the correct stage of lesion of different diseases; avoiding creating artifacts during removal and fixation; and give full details of history, clinical diagnosis, and differential diagnoses on the laboratory request sheet. Pathology reports describing the subtleties of histologic changes are difficult to write, particularly if the lesions are not specific. Overly long histologic reports...
Sullivan M, Burrell MH, McCandlish IA.A nine-and-a-half-year-old three quarters thoroughbred gelding was presented with unilateral epistaxis. The cause was a destructive, progressive haematoma in the left maxillary sinus. In all previous reports of progressive haematomata in the equine nasal cavity, the site of origin has been the ethmoidal labyrinth. Surgical removal of the progressive haematoma resulted in an apparent cure.
Coggins L.Presently available data continue to support the idea that once a horse is infected with equine infectious anemia virus it remains infected indefinitely. Infection may not always be demonstrated by inoculation of plasma, serum, or whole blood transfusions into susceptible recipients, but transfusions of fresh whole blood will be infective in at least 95% of the horses testing positive in the agar gel immunodiffusion test. For detection of infectivity in a small percentage of inapparent carriers, it appears necessary to inoculate washed leukocytes collected over a period of time.
Valberg SJ, McKinnon AO.Five horses with fatal clostridial cellulitis are described. The characteristic findings were the rapid development of a crepitant swelling with an associated toxemia, which in four cases followed intramuscular injections. The clinical features, diagnostic techniques and pathogenesis are discussed. The importance of an early diagnosis is emphasized.
Asbury AC, Gorman NT, Foster GW.The addition of serum to uterine secretions was shown to opsonize Streptococcus zooepidemicus and significantly enhance bacterial phagocytosis by equine neutrophils. Treatment of serum by heat inactivation at 56 degrees C, EDTA treatment, and C3 consumption reduced phagocytosis and therefore demonstrated that the process was complement-dependent. The amount of C3 present in uterine secretions was measured in a series of 14 mares infected with Streptococcus zooepidemicus . Ten of the 14 mares had detectable amounts of C3; however, the C3 had been cleaved and rendered nonfunctional. The importan...
Gillespie J, Kalica A, Conner M, Schiff E, Barr M, Holmes D, Frey M.From 105 field cases of diarrhea in neonatal or young foals, rotavirus was detected by electron microscopy (EM) and/or by enzyme-linked immunosorbent assay (ELISA) in the feces of 65 foals on 16 different premises. ELISA was performed with Rotazyme test kits developed by Abbot and Company for the detection of rotaviruses. Twenty-four field isolates from the feces of diarrheic foals with equine rotavirus infection as ascertained by EM were placed in MA-104 cell cultures after pretreatment of the viral suspension with 10 micrograms ml-1 of trypsin and incorporation of 0.5 micrograms ml-1 or 1 mi...
Issel CJ, Foil LD.There are several factors involved in the mechanical transmission of equine infectious anemia (EIA) virus by insects. Large hematophagous insects, especially tabanids, which feed from extravascular sites (ie, pool feeding) appear to be the most efficient vectors. The biology of the host-seeking and blood-feeding behavior of the vectors are important variables that have been overlooked in the mechanical transmission of pathogens like EIA virus. The biology, population levels, and diversity of the vectors, in addition to the clinical status and proximity of EIA virus-infected horses maintained w...
Conner M, Kalica A, Kita J, Quick S, Schiff E, Joubert J, Gillespie J.Reoviruses have been isolated from a number of species including human, bovine, feline, canine and equine. In most species they seem to produce mild to inapparent disease. We have isolated a reovirus type 3 from a foal with diarrhea. The virus designated the Ralph strain has been propagated in both the MA-104 and A-72 cell lines. The strain produced cytoplasmic inclusion bodies in these cell cultures. Tissue-cultured virus fixed complement in the presence of reovirus antibodies, but failed to do so in the presence of rotavirus antiserum. By electron microscopy the viral particle measured +/- 6...
Staczek J, Wharton JH, Dauenhauer SA, O'Callaghan DJ.Semipermissive, primary hamster embryo (HE) cells were morphologically transformed in vitro by infection with UV-irradiated equine cytomegalovirus (equine herpesvirus type 2; ECMV). Cell lines (designated EC-1-3) were established independently from foci and were shown to exhibit growth and biological properties typically associated with transformed cells: altered morphology, loss of contact inhibition, increased saturation density, decreased generation time, immortality in culture, normal growth in low concentrations of serum, colony formation in soft agar, and resistance to ECMV superinfectio...
Bain FT, Brock KA, Koterba AM.High-frequency jet ventilation was performed on a premature foal for respiratory difficulty attributable to in utero-acquired pneumonia. The procedure involves delivery of compressed gas through a small-bore cannula at frequencies up to 400 cycles/min. Ventilation settings of drive pressure, frequency, and FIO2 were varied to optimize PaO2 and PaCO2 values. The foal was ventilated with this equipment for 14 hours. Evidence of a favorable response to this method of ventilation was observed in the form of improvement in arterial blood gas values as well as the foal's attitude and degree of respi...
Marqués FJ, Sharma A, Wilson DG.Advanced diagnostic imaging and histopathological investigation were performed in an adult horse with chronic facial swelling due to a bone sequestrum and abscessation. In contrast to other cases, there were no draining tracts, difficulty eating, weight loss, head shaking, or fistula formation between the oral cavity and the maxillary sinus. Une investigation d’imagerie diagnostique avancée et un examen histopathologique ont été réalisés chez un cheval adulte présentant de l’enflure faciale chronique attribuable à un séquestre osseux et à une abcédation. Par contraste à d’aut...
Manneveau GB, Robert MP, Tessier C, Bizon-Mercier C.This report describes a rare case of gastric impaction caused by a trichophytobezoar in a foal. This case highlights the difficulty in diagnosing this condition and reports surgical removal via a gastrotomy after failure of medical treatment. Ablation chirurgicale d’un trichophytobézoar gastrique chez un poulain. Ce rapport décrit un rare cas d’obstruction gastrique causé par un trichophytobézoar chez un poulain. Ce cas souligne la difficulté à diagnostiquer cette affection et fait rapport sur l’ablation chirurgicale lors d’une gastrotomie après l’échec du traitement médical...
Sonmez K, Gurel A, Takai S.The aim of the present study was to develop an immunocytochemical procedure for the early detection and demonstration of Rhodococcus equi in smears of tracheal aspirates taken from live foals in field conditions. Tracheal wash samples were collected from thoroughbred foals, aged 1-5 months and located in studs around Bursa and Istanbul, Turkey. Some foals were suspected of having R. equi infection on the basis of clinical examination (n=56) and others were unaffected control animals (n=54). Serum samples were also collected from each foal for testing for the presence of R. equi-specific antibo...
Weidenhöfer V, Martin H, Peters J.Since the late 9th century, scientific literature in Arabian language, based on the translation and compilation of works of the Classical, Persian and Indian culture considerably increased. This also applies to the field of veterinary medicine, as is illustrated by a number of hippological and hippiatric treatises. Affinities between texts on horse medicine in Antiquity and in Arabian literature have been mentioned by philologists, but the degree of dependence on classical texts could not be verified due to the lack of translations of the Arabian texts. In this respect, the oldest available te...
Roumen MP, Borgsteede FH, Vos JH.In autumn 2002 and 2003, the Animal Health Service received several young horses for post mortem investigation that had died or had been euthanised. It was found that severe cyathostominosis was the cause of death. The aetiology, pathology and diagnosis of this infection is discussed. Advice is given for preventative measures and usage of anthelmintics.