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.
Whithair KJ, Bowersock TL, Blevins WE, Fessler JF, White MR, Van Sickle DC.Septic arthritis was induced in one antebrachiocarpal joint of seven horses by the intra-articular injection of 1 mL Staphylococcus aureus suspension containing a mean of 10(5) colony-forming units. Twenty-four hours after inoculation, four horses were treated by regional perfusion with 1 g of gentamicin sulfate, and three horses received 2.2 mg/kg gentamicin sulfate intravenously (IV) every 6 hours. Synovial fluid was collected for culture and cytology at regular intervals, and the synovial membranes were collected for culture and histologic examination at euthanasia 24 hours after the first ...
Hance SR, Bramlage LR, Schneider RK, Embertson RM.Medical records of 38 horses less than 1 year of age and diagnosed as having a fracture of the femoral diaphysis, metaphysis or distal physis were evaluated. Twenty-six foals had fractures of the femoral diaphysis or metaphysis with the most common fracture configuration being comminuted. Twelve foals had distal physeal fractures with the most common fracture configuration being a Salter-Harris type II. Twenty-one foals with fractures of the capital femoral physis, neck or greater trochanter during the same time period were excluded from this study. Surgical repair was attempted in 16 diaphyse...
Sanada Y, Noda H, Nagahata H.Serological survey of Rhodococcus equi infection in horses in Hokkaido was performed using ELISA. Of 2,879 horse sera, 318 (11.0%) gave antibody-positive (OD greater than or equal to 0.3) reactions. The antibody-positive rate of female was significantly higher (p less than 0.01) than that of male, and no statistical difference between Anglo-Arab and thoroughbred was detected in the antibody-positive rate. The maximum antibody-positive rate (27.1%) was shown at 14 years of age. The antibody-positive rates on the 160 farms were found to vary widely from 0 to 78.9%. A significant difference (p le...
Mendoza L, Villalobos J, Calleja CE, Solis A.Two vaccines to treat phythiosis insidiosi in horses were evaluated in 71 Costa Rican horses between 1982 to 1988. One vaccine used a cell-mass (CMV) as antigen and the other a soluble concentrated antigen (SCAV). Both vaccines cured horses infected with Pythium insidiosum (p value approximately 14%). The age of lesions prior to vaccination was important in the response of the horses to immunotherapy. All horses with lesions 0.5 months or less in duration were cured regardless of the vaccine used. Horses with lesions two or more months old did not respond to either vaccine. The age of the hors...
van Duijkeren E, Sloet van Oldruitenborgh-Oosterbaan MM, Rijkenhuizen AB, Ensink JM.An obstruction of the small intestine was suspected in two ponies with colic. At surgery and at necropsy, the cause of the colic appeared to be an inflammation process caused by perforation of the jejunum by a piece of wire. One pony recovered after laparotomy and enterectomy, but had to be put down eight weeks later because of severe laminitis. The other pony was euthanized immediately after clinical evaluation.
Couto MA, Harwig SS, Cullor JS, Hughes JP, Lehrer RI.Endogenous, cysteine-rich antimicrobial peptides known as defensins are prominent components of human, rabbit, and rat neutrophils, yet little is known about their occurrence in other mammalian species. Although we did not detect mature (i.e., processed) defensins in equine neutrophil granules, we found that these granules contained small amounts of other cysteine-rich peptides with antimicrobial activity. One of these, eNAP-1, was purified by a combination of gel permeation and reversed-phase high-performance liquid chromatography from acid extracts prepared from the cytoplasmic granules of e...
Laviada MD, Babín M, Dominguez J, Sánchez-Vizcaíno JM.A sandwich enzyme-linked immunsorbent assay (ELISA) for rapid detection of African horsesickness virus (AHSV) in infected spleens or cell culture supernatant was developed. This method uses two monoclonal antibodies (MAbs) which recognize two non-overlapping epitopes of the major core protein (VP7) to coat the solid phase, and one labeled with biotin as second antibody. This ELISA was evaluated for its ability to detect AHSV in infected spleens resulting in a sensitivity of 97.4% and a specificity of 100% compared with virus isolation in cell culture, and can be used for the detection of the n...
MacKay RJ, Lester GD.Because hepatocyte-stimulating factor/interleukin 6 (IL-6) is the principal inducer of acute-phase protein synthesis in the liver, quantification of its activity in blood provides an early and sensitive assessment of the acute-phase response. Circulating IL-6 activity was monitored in 4 adult horses for 72 hours after IV administration of endotoxin. In 4 experiments performed at weekly intervals and in randomized order, each horse was given endotoxin--1,000 30, 1, and 0 ng/kg of body weight. Plasma IL-6 activity was quantified as the ability to promote growth of the IL-6-dependent B-cell hybri...
Moll HD, Schumacher J.A 2-year-old Tennessee Walking Horse colt was admitted for evaluation of signs of abdominal pain, inappetence, and constipation of 5 days' duration. Two days prior to the onset of signs, the owner had cut the sacrococcygeal muscles as part of a tail-setting procedure. On examination, the horse was febrile and lethargic, and intestinal sounds were not heard on auscultation. Results of peritoneal fluid analysis were indicative of peritonitis. The horse continued to deteriorate and died despite treatment with antimicrobials, flunixin meglumine, and balanced electrolyte solution. At necropsy, the ...
Tsunemitsu H, Jiang B, Saif LJ.Enzyme-linked immunosorbent assays (ELISAs) were developed to detect group (gp) C rotavirus antigens and antibodies. Both assays were confirmed to be specific for gp C rotavirus by using serogroup A, B, and C rotaviruses; hyperimmune antisera to these serogroups of rotaviruses; and paired serum specimens from animals infected with gp C rotaviruses. The ELISA for antigen detection reacted not only with porcine gp C rotaviruses but also with human and bovine gp C rotaviruses. Following experimental challenge of gnotobiotic pigs with porcine gp C rotavirus, the virus was found by ELISA in all dia...
Böse R, Daemen K.Babesia caballi-infected or normal equine erythrocytes were solubilized in sodium dodecyl sulfate (SDS) buffer and analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Antigens were allowed to react with sera from horses experimentally or field-infected with B. caballi and with sera from non-infected horses. Major babesial antigens recognized by immune sera had apparent mol. wts of 141, 112, 70, 50, 48, 34, and 30 kDa. The polypeptides at 50 and 48 kDa were recognized earliest and throughout infection, but also weakly by 3/100 equine sera tested negative and 1/33...
Bennett DG.Routine examination of the digestive system relevant to purchase includes gross examination of the feces, auscultation of the abdomen, and examination of the oral cavity and teeth for verification of age and identification of any gross abnormality. Further examination is indicated only when there is a history of diseases such as colic, especially colic surgery, or esophageal obstruction. Special procedures that might be indicated, depending upon the history and findings on the routine physical examination, include rectal palpation of the abdominal viscera; endoscopic examination of the esophag...
Zaugg JL, Lane VM.We evaluated the efficacy of buparvaquone in eliminating infection with Babesia equi of European origin in carrier horses and in splenectomized horses with experimentally induced acute infection. When administered at the rate of 5 mg/kg of body weight, IV, 4 times at 48-hour intervals, buparvaquone prompted rapid abatement of parasitemia. However, secondary and tertiary recrudescent parasitemias invariably returned with establishment of the carrier state. Buparvaquone, at the dosage evaluated, had transitory therapeutic efficacy against acute B equi infection in splenectomized horses, but was ...
Proudman CJ, Edwards GB.A centrifugation/flotation technique for the identification of equine tapeworm eggs is described. It was validated by using faeces samples from 80 horses of known tapeworm status, and had a sensitivity of 61 per cent and a specificity of 98 per cent. The exclusion of false negative results in animals with less than 20 tapeworms increased the sensitivity to 92 per cent. No significant correlation was found between the number of eggs observed and the number of tapeworms present in the horses.
Chaffin MK, Schumacher J, Hooper N.A 5-month-old male Quarter Horse was examined because of multicentric, granulomatous, cutaneous lesions of the dorsum and prepuce. The cutaneous lesions were excised, and sodium iodide was administered orally for 2 weeks. Multicentric cutaneous pythiosis was diagnosed by histologic examination and immunoperoxidase staining of excised tissues. By 3 months after surgery, all lesions had healed.
Baxter GM, Doran RE, Allen D.Proximal open comminuted fractures of the fourth metatarsal bone (Mt IV) in eight horses were treated by complete removal of the affected bone and antimicrobial therapy. Two horses had concurrent septic arthritis of the tarsocrural or distal tarsal articulations, and five horses had radiographic evidence of osteomyelitis and sequestration of the affected bone. Five horses became athletically sound for their intended use, two horses with septic arthritis had residual lameness but were pasture sound, and one horse was lost to follow-up. Excision of the entire bone appears to be an acceptable tre...
Ball MA, Weldon AD.A 5-year-old Appaloosa gelding was presented with a history of intermittent multiple joint swelling, weight loss, and anemia. Physical examination and clinical pathology revealed a grade IV/VI holodiastolic murmur, louder on the left, and a marked hyperproteinemia. Echocardiography of the heart demonstrated a large vegetative lesion on one of the aortic valve cusps. Blood cultures did not elucidate the causative organism, and the disease was refractory to empiric antibiotic therapy. The horse was euthanized after approximately 2 months of therapy.
Oladosu LA, Olufemi BE.An investigation was carried out to study the haematology of steroid immunosuppressed horses experimentally infected with Babesia equi and Ehrlichia equi, separately or simultaneously. Horses infected with both pathogens showed less marked changes in their haematology than those inoculated with either pathogen separately. This appeared to result from early elimination of the more pathogenic Babesia as Ehrlichia spread through the granulocytes. The apparent suppression of Babesia by Ehrlichia is of field clinical importance and merits further investigation for its apparent useful potentials in ...
Folz SD, Hanson BJ, Griffin AK, Dinvald LL, Swerczek TW, Walker RD, Foreman JH.Ceftiofur sodium was evaluated as a therapy for respiratory infections in horses. This cephalosporin antimicrobial was administered intramuscularly every 24 h and at a dose of 2.2 mg/kg (1.0 mg/lb) of body weight. The efficacy of ceftiofur sodium was compared with that of a positive control drug, ampicillin sodium (recommended dose of 6.6 mg/kg [3 mg/lb], given every 12 h). Both treatments were continued for 48 h after clinical symptoms were no longer evident (maximum of 10 days). Fifty-five (55) horses with naturally acquired respiratory infections were included in the study; 28 were treated ...
Adeyefa CA.The precipitin response of the mitogen produced by Strongylus vulgaris arterial larvae was investigated. IgG (T) from the sera of horses naturally infected with S. vulgaris adults and arterial larvae recognised the presence of two antigenic components of the mitogenic fractions. The results obtained seem to confirm that these antigens are immunogenic in stimulating the production of increased levels of IgG(T) in infected animals, and showed that the procedures could be used as immunological tools in the diagnosis of S. vulgaris infection.
Vacek JR, Macharg MA, Phillips TN, Foerner JJ, Everett KA.A 3-month-old Thoroughbred colt was presented with signs of colic. Findings from physical examination, abdominal paracentesis, abdominal radiographs and clinical pathology revealed uroperitoneum secondary to a calculus obstructing the urethra and causing subsequent urinary bladder rupture. Analysis of the calculus demonstrated a tissue center with outer concretions composed primarily of struvite.
Gibson JS, Slater JD, Field HJ.The sequencing of the genome of equine herpesvirus-1 (EHV-1) is reported in Elizabeth A. R. Telford, Moira S. Watson, Kathryn McBride, and Andrew J. Davison, 1992, Virology, 189, 304-316. The sequence was derived using a plaque-purified clone of EHV-1 strain Ab4 (designated Ab4p). To ensure that Ab4p shares the pathogenic characteristics of parental Ab4 (hereafter Ab4), both were inoculated intranasally into foals, specifically free from EHV-1 and EHV-4. Clinical signs, including rectal temperature, were similar for both viruses. In addition, nasal shedding of virus was observed over a 1- to 2...
Smith KC, Whitwell KE, Binns MM, Dolby CA, Hannant D, Mumford JA.From 1988 to 1991, 51 pregnant pony mares were challenged intranasally or by aerosol with an isolate of EHV-1 (AB4) originally recovered from a quadriplegic mare. This resulted in 32 abortions, occurring from 9 to 29 days after infection. In 14 of the early abortions (Days 9-14), EHV-1 was not demonstrated in the foetal tissues by virus isolation or immunostaining despite no other non-viral cause for the abortion being evident. Application of the polymerase chain reaction to foetal tissues from 9 of these cases also proved negative. One of the 14 mares was destroyed immediately after abortion,...
Swardson CJ, Kociba GJ, Perryman LE.Direct effects of equine infectious anemia virus (EIAV) on hematopoiesis in vitro were studied. Bone marrow mononuclear cells from clinically normal horses were incubated with 100 TCID50 of EIAV/10(7) cells. These cells were cultured to assay for colonies derived from erythroid progenitors, granulocyte/monocyte progenitors, and fibroblastic progenitors. The EIAV had a selective suppressive effect on the erythroid progenitors. Colony-forming units-erythroid were suppressed to 80% of that for medium controls (P = 0.011). Burst-forming units-erythroid were suppressed to 70% of that for medium con...
Boy MG, Zhang C, Antczak DF, Hamir AN, Whitlock RH.A 10-month-old Arabian foal was evaluated for a suspected immunoglobulin (Ig) M deficiency. Decreased to nondetectable concentrations of IgM, IgA, and IgG (T), and a normal concentration of IgG, were present. Results of in vitro testing of the blood lymphocyte blastogenesis showed a weak response to the B-cell mitogen, lipopolysaccharide (LPS), but normal responses to T-cell mitogens. Results of postmortem examination showed synovitis of the left tibiotarsal and both scapulohumeral joints. Atrophy and edema of the lymph nodes and lymphocyte depletion in the thymus and spleen were seen. A subac...
Magni E, Bertelloni F, Sgorbini M, Ebani VV.To investigate the occurrence of Bartonella sp. infection in asymptomatic horses and donkeys living in Tuscany, Central Italy. Methods: Blood samples were collected from 77 horses and 15 donkeys and tested by indirect immunofluorescent test to detect antibodies against Bartonella sp. and by PCR to detect the pathogen. Results: Fifty-four (58.69%; 95% CI: 47.95%-68.87%) animals, 9 donkeys and 45 horses, were seropositive with antibody titers ranging from 1:64 to 1:512. PCR assays detected 9 horses positive for Bartonella sp. and 3 donkeys for Bartonella henselae genotype I. Conclusions: The det...
The Journal of hygieneAugust 1, 1981
Volume 87, Issue 1 93-100 doi: 10.1017/s0022172400069278
Lemcke RM, Ernø H, Gupta U.Two unidentified mycoplasmas, N3 and N11, isolated from the respiratory tract of horses, were found to cross-react with strains of M. mycoides subsp. mycoides in indirect immunofluorescence tests, growth-inhibition tests carried out by the running drop/agar-well method, and in complement-fixation and double immunodiffusion tests. Serologically, the equine mycoplasmas were not completely identical with any of the reference strains of M. mycoides with which they were compared. Their cultural characteristics, ability to digest coagulated serum and casein, and survival at 45 degrees C, however, su...
Alsing-Johansson T, Pedersen A, Bergström K, Sternberg-Lewerin S, Penell J, Bergh A.Equine dentistry has developed immensely and human dental equipment, such as handpieces, are often used. Measures to avoid the spread of infectious microorganisms are important, but this is challenging since handpieces are difficult to decontaminate. Thus, it is necessary to develop effective IPC measures in equine dentistry. The aim of this study was to contribute to the evidence needed for future evidence-based guidelines on IPC by investigating hygiene in equine dentistry. Used handpieces and dummies (i.e., handpieces not used during dental procedure, reflecting environmental bacterial cont...
Aldrovandi AL, Osugui L, Acqua Coutinho SD.The objective of this study was to characterize genotypically Malassezia spp. isolated from the external ear canal of healthy horses. Fifty-five horses, 39 (70.9%) males and 16 (29.1%) females, from different breeds and adults were studied. External ear canals were cleaned and a sterile cotton swab was introduced to collect cerumen. A total of 110 samples were cultured into Dixon medium and were incubated at 32°C for up to 15 days. Macro- and micromorphology and phenotypic identification were performed. DNA was extracted, strains were submitted to polymerase chain reaction technique, and the ...
Goto H, Shimizu K, Taya Y, Noda H, Tokunaga T.The antibody responses to equine influenza viruses were investigated during a postepizootic period of the disease. Serum samples were collected from a total of 128 horses on three occasions during the years 1967-77. No significant increase of hemagglutination-inhibition antibody titers to subtypes 1 and 2 of equine influenza virus were detected in any of the sera tested. The maternal hemagglutination-inhibition antibody titers of foals decreased over a four month interval. A marked increase of the titers was recognized in only the equine influenza virus vaccinated horses. These findings sugges...
Warko G, Bostedt H.Eight vital, new-born foals were additionally administered a non-species-specific colostrum-substitute via stomach-tube within the first 18 hours of their life. The substitute had been made of cattle-colostrum. These foals as well as a control-group of eight foals constantly had free access to maternal colostrum. Object of measurement was GGT-activity in the blood-serum. The increase of GGT-activity within the first 24 hours after birth was very low in the control-group (up to 25 U/l), and very high in the tested animals (418 +/- 182 U/l). Obviously there is a direct connection between this ri...
Farahi S, Shishehbor P, Nemati A, Witaliński W.A new mite species, Trachygamasus karuni sp. nov. is described from buffalo, sheep and horse manure at several locations north of Ahvaz city, Khuzestan, Iran. A key to 14 world species of Trachygamasus with described adults is also provided.
Doyle AJ, Saab ME, Lewis K, McClure JT.Alcohol-based antisepsis has been extensively studied in human health care, but only little information is available regarding efficacy and tolerance in other species. The purpose of this study was to determine if an alcohol-based antiseptic is effective at reducing bacterial counts on equine skin and the appropriate contact time to do so, without causing any adverse skin reactions. Samples were collected before and after preparation from clipped sites over both jugular veins of horses and were plated on 3M Petrifilm Aerobic Count Plates in duplicate. Trial 1 tested an alcohol-based product (E...
Mair TS, Lane JG, Lucke VM.The clinical and post mortem features of 11 cases of lymphosarcoma involving the thoracic cavity are reviewed. The clinical findings included inappetence, weight loss, pectoral oedema, dyspnoea, pleural effusion and distension of the jugular veins. Dysphagia was present in three cases. At post mortem examination lesions were found in the abdomen as well as the chest in eight cases; clinical signs of abdominal disease were present in two cases. The features of nine other similar cases recorded in the literature are reviewed.
Groom LJ, Gaughan EM, Lillich JD, Valentino LW.Arthrodesis was performed to treat septic arthritis of the proximal interphalangeal joint of 8 horses. Records of the horses were reviewed to determine outcome and possible factors that influenced success or failure. All horses were female. Seven horses had 1 joint treated and 1 horse was treated for bilateral pelvic limb involvement. The duration of sepsis before surgery ranged from 1 to 66 days. Bone lysis and production was radiographically apparent in 7 horses before surgery. Six horses had multiple bacterial organisms cultured from bone or synovial tissues; 2 horses had single isolates id...
Cudmore LA, Groenendyk JC, Hodge P, Church S.This case report describes neurological signs associated with a pyogranulomatous lesion within the sacral vertebral canal of a horse. The clinical findings included urinary overflow incontinence and reduced anal, perianal and tail tone. The horse failed to respond to medical management and a guarded prognosis for return to athletic performance initiated the decision for euthanasia.
Pégné JC, Duquesne F, Laugier C, Lequeux G, Petry S.The present study reports the isolation of A. hippocoleae from genital swabs of 15 apparently healthy mares (at least one had an abortion one month earlier) and describes the genotypic and phenotypic characterisation of these strains. The mares were of eight different breeds with a thoroughbred dominance and came from 11 breeding farms located in the French region of Brittany. 16S rRNA gene sequencing confirmed the species' identification by comparing it with reference strain A. hippocoleae CIP 106850. Some degree of natural divergence within A. hippocoleae was observed by 16S rRNA sequencing ...
Valdez RA, DiPietro JA, Paul AJ, Lock TF, Hungerford LL, Todd KS.The bioequivalence of Strongid C and generic pyrantel tartrate was determined in a controlled study using 30 horses with naturally acquired endoparasitic infections. Three horses were randomly allocated to each of ten replicates based on quantitative nematode and ascarid egg counts and fecal larvae culture results. Horses within each replicate were randomly assigned to one of three treatment groups. Horses in Treatment Group 1 received only oats; horses in Treatment Group 2 received generic pyrantel tartrate pellets (2.65 mg pyrantel tartrate kg-1) mixed with oats; horses in Treatment Group 3 ...
Bertone AL, Jones RL, McIlwraith CW.The tarsocrural joints of 11 horses were inoculated with 1.2 to 2.16 x 10(6) viable Staphylococcus aureus organisms susceptible to a trimethoprim-sulfadiazine (TMP-SDZ) combination with minimal inhibitory concentration (MIC) of 0.25 micrograms of TMP/ml and 4.75 micrograms of SDZ/ml. Antimicrobial treatment consisted of oral administration of a TMP-SDZ combination--30 mg/kg of body weight given once daily (group-1 horses) or 60 mg/kg given as 30 mg/kg every 12 hours (group-2 horses). Paired serum and synovial fluid samples were obtained before intra-articular inoculation with the S aureus, aft...
Farah Haziqah MT, Nur Hikmah AM, Mat Hasan H, Hamdan A, Nik Him NAII.An investigation was undertaken for screening and isolating nematophagous-fungi from the faecal samples of various grazing animals and soils in Malaysia. Total of 111 faeces and 50 soil samples were collected and the samples were cultured on 2% water agar plates. The growth of nematophagous-fungi was stimulated by sprinkling-baiting technique. The conidia of suspected nematophagous-fungi were inoculated on 2% water agar plates. All isolated were maintained on 2% cornmeal agar plates. Verticillium spp., Fusarium spp. and Arthrobotrys spp. were identified from the faecal and soil samples. 62.5% ...