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.
Diesing L, Steuber S, Ahmed JS.Using luminol-dependent chemiluminescence (LCL), the specificity of antibodies to variable antigen type (VAT)-populations of Trypanosoma evansi was studied in four infected ponies. Trypanosomes of each wave of parasitemia were isolated and multiplied in irradiated mice. Their opsonization by serum collected during the infection was investigated with LCL and results for isolated VAT-populations are shown in the paper. Antibodies specific to each VAT-population were first found three days after the maximum of a parasitemic wave. There was no cross reactivity between different VAT-populations. LC...
Broström H, Obel N, Perlmann P.Human lymphocytes displayed a frequent natural cytotoxicity (NK) in vitro against normal equine dermal fibroblasts (ED) and against equine tumour cells of a virus-containing cell line (Mc-1). Similarly, human normal sera contained antibodies that induced antibody-dependent cellular cytotoxicity (ADCC) by normal human lymphocytes against the same target cells. Both NK and ADCC varied for different donors. For individual donors, however, cytotoxicity against the two target cells was significantly correlated both in NK and ADCC. For ED there was also a significant correlation between ADCC and NK ...
Kent JE, Blackmore DJ.This paper describes the quantitative measurement of IgG concentrations in equine blood/serum by turbidimetric analysis and the qualitative assessment using latex agglutination. The concentration of IgG in foal serum measured by turbidimetry correlated well with the results obtained by radial immunodiffusion (r = 0.91) and the gamma-globulins estimated from the electrophoresis of serum on cellulose acetate (r = 0.92). The method, using antibody-coated latex beads, to detect foals with serum IgG concentrations of less than 4 g/litre (whole blood less than 2 g/litre) proved to be accurate in 96 ...
Tulleners EP, Richardson DW, Reid BV.Three mares were treated for vaginal evisceration of a portion of the small intestine. Evisceration occurred in 2 mares shortly after breeding accidents in which the stallion's penis penetrated the vaginal fornix dorsal to the cervix. The affected bowel was replaced through the laceration, and the vaginal defects were sutured with the mares standing, utilizing epidural anesthesia. One mare recovered without complications, was subsequently bred, and delivered a foal with no difficulty. The other mare developed signs of a strangulating small intestinal obstruction 24 hours after the injury, nece...
Freeman KP, Roszel JF, Slusher SH.Inclusions and cellular changes were seen in cytologic specimens from 1 healthy horse, 6 horses hospitalized because of respiratory problems, and 1 horse hospitalized because of colic and hepatitis. Two bronchial aspirates contained detached ciliated cytoplasmic tufts and cytoplasmic inclusions characteristic of the specific degenerative process called ciliocytophthoria. These changes and inclusions resembled those seen in bronchial aspirates from human beings with parainfluenza virus infection. Four bronchial aspirates and 2 serous fluid specimens had nuclear inclusions resembling those seen ...
Hinrichs K, Gentile DG, Hurtgen JP, Richardson DW.A testicular prosthesis was removed from the scrotum of a 3-year-old Quarter Horse stallion. The prosthesis had been placed in the left side of the scrotum 10 months earlier, after an unsuccessful attempt to reposition the retained left testis. Because of a persistent draining fistula on the scrotum, first noted 5 months after placement of the prosthesis, surgery was performed to remove the prosthesis. At surgery, the left testis was found in a fibrous mass surrounding the prosthesis. The left testis had descended after placement of the prosthesis, and its involvement in the fibrous tissue sur...
Simmons HA, Cox JE, Edwards GB, Neal PA, Urquhart KA.This paper reports seven cases of penile paraphimosis which occurred in both entire and castrated horses in association with general debility. Two cases were discharged after treatment while still suffering from partial paralysis; one was discharged at the owner's request with complete paralysis; three were destroyed and one died during treatment. Identified causes of debility were malnutrition, severe parasitism, glucose malabsorption and salmonellosis.
Rigg DL, Ramey DW, Reinertson EL.Respiratory distress and laryngeal paralysis were found to be caused by a Streptococcus equi abscess of cranial mediastinal lymph nodes, putting pressure on the trachea at the thoracic inlet. Surgical drainage was required to relieve the compression, and long-term antibiotic therapy was used to treat the bacterial infection. The trachea returned to normal diameter but left laryngeal hemiplegia persisted. Peritracheal abscesses should be considered in the differential diagnosis of inspiratory dyspnea of the horse.
Biberstein EL, Jang SS, Hirsh DC.From 1965 to 1983, Nocardia asteroides infection was diagnosed in 16 horses at the Veterinary Medical Teaching Hospital, University of California, Davis. In 2 of the cases, the infection was traumatic in origin and local in extent; the horses recovered without relevant antimicrobial therapy. Fourteen horses had pulmonary or disseminated infections that ended fatally. All 14 had various degrees of immunosuppression. Of these, 8 were Arabian foals with combined immunodeficiency disease and 3 were aged horses with hyperadrenocorticism secondary to ACTH-secreting pituitary tumors. Of the other 3, ...
Sullins KE, Stashak TS, Mero KN.In 6 horses, 2 types of ischemic lesions were created in small intestinal segments by selective ligation of vessels and intestinal wall for 1, 2, or 3 hours. After confirming the ischemia by IV injection of sodium fluorescein, the ligatures were released. Five minutes later, the fluorescent patterns were documented photographically. Observed patterns ranged from normal (identical to that observed in unaffected bowel) to a patchy distribution of non-fluorescence (indicating incomplete perfusion). None of the experimental segments was normal when reevaluated 1 month later. The typical appearance...
Science (New York, N.Y.)February 1, 1985
Volume 227, Issue 4686 522-524 doi: 10.1126/science.3880925
Holland CJ, Ristic M, Cole AI, Johnson P, Baker G, Goetz T.Potomac horse fever, a disease characterized by fever, anorexia, leukopenia, and occasional diarrhea, is fatal in approximately 30 percent of affected animals. The seasonal occurrence of the disease (June to October) and evidence of antibodies to the rickettsia Ehrlichia sennetsu in the serum of convalescing horses suggested that a related rickettsia might be the causative agent. Such an agent was isolated in cultured blood monocytes from an experimentally infected pony. This intracytoplasmic organism was adapted to growth in primary cultures of canine blood monocytes. A healthy pony inoculate...
Moorthy AR, Spradbrow PB.
Summary:
During a survey in Queensland in 1974—77 four strains of rickettsia-like organisms were isolated from the respiratory tract of horses, of which two, NS7 and NS68 were isolated from nasal swabs of clinically normal horses and two, KSDH 91 and NSDH 100, from lung samples of slaughtered horses showing gross pathological lesions in the form of acute bronchiolitis and subacute interstitial pneumonia, respectively. The isolates are characterised as rickettsia-like organisms on the basis of their morphology, tinctorial property, growth in chicken embryos, inability to grow on bacteria...
Widders PR, Stokes CR, David JS, Bourne FJ.The immunoperoxidase technique was adapted for the identification of free immunoglobulin and immunoglobulin producing cells in equine tissues. Staining specific for free IgG, IgA and IgM was detected at all levels of the reproductive tract, and secretory component staining was present in the uterine epithelium but not in the oviduct, cervix or vagina. Immunoglobulin producing cells were present at all levels of the tract, with IgG and IgA cells at equivalent concentrations, but with fewer IgM cells. There was no cyclical trend in free immunoglobulin staining, or plasma cell numbers. IgG and Ig...
Diehl M, Gerber H, Schifferli D, Nicolet J.A systemic investigation of wound infection in the horse after operative treatment of large wounds reveals that the age of the wound is of critical importance. The limit for an uncomplicated healing process lies around four hours. The duration of the operation itself is of little significance, the location of the lesion on the body of the horse, however, plays a major role. The pattern of isolated bacterial organisms is discussed in relation to the duration of hospital treatment. It is concluded that a systemic antibiotic therapy is of no value and that a local antibiotic therapy is only indic...
Hietala SK, Ardans AA, Sansome A.An enzyme-linked immunosorbant assay was developed to measure naturally occurring Corynebacterium equi specific antibody in horse serum. Antibody against C equi was demonstrated in normal adults and was passively transferred to foals. Adult levels of specific antibody were reached by 5 to 6 months of age in healthy foals. Decreased early antibody levels were demonstrated in a limited number of foals with confirmed C equi infection.
Guerrero J, Newcomb K, Seibert BP, Michael BF.Two controlled tests were conducted in equine foals and yearlings to determine the optimal oral dosage and the duration of activity of closantel for the prevention of Gasterophilus spp larval infections. Additional data were collected on the activity of closantel against Strongylus vulgaris larval infections. In experiment 1, 12 foals and 12 yearlings were equally allocated to 4 experimental groups, and were given oral treatments with closantel at dosages of 0 (nontreated controls), 2, 5, or 8 mg/kg of body weight every 2 months during bot season. The foals and yearlings were allowed to graze ...
Khan ZU, Misra VC, Randhawa HS.Prevalence of serum precipitins against Micropolyspora faeni, Thermoactinomyces vulgaris and Aspergillus fumigatus, employing the counterimmunoelectrophoresis (COIE) and Ouchterlony's double diffusion (DD) techniques, is reported in 162 of the equines stationed at two military installations in north-western India. M. faeni specific precipitins were demonstrable in 58 of 112 mules from site I in the mountainous region whereas the results were negative for all of the 50 horses examined from site II located in the plains. Of the 58 M. faeni positive mules, 45 (78%) had signs and symptoms suggesti...
Cheevers WP, McGuire TC.Equine infectious anemia (EIA) is a chronic, relapsing infectious disease of horses caused by a nononcogenic retrovirus. Virus persists in infected animals for life and can be reliably detected by serologic tests that measure levels of antibody to the major structural protein of the virus. Periodic virus replication in macrophages leads to an immunologically mediated acute disease characterized primarily by severe anemia. Recrudescence of acute EIA is the result of antigenic variation of the surface glycoprotein of EIA virus. The frequency and severity of clinical episodes of EIA decrease in m...
Jacob RJ, Price R, Allen GP.Equine herpesvirus type 3 (EHV-3) DNA, isolated from purified virions of the large-plaque strain, was digested with the restriction endonucleases XbaI, Bg/II, EcoRI, and HindIII. Several lines of evidence indicated that the DNA extracted from purified virions was composed of long (L) and short (S) components and was present as two isomeric forms, P and IS. The evidence included: (i) after electrophoresis on agarose gels, the summed molecular weights of the digestion products exceeded that expected from intact, unit size DNA; (ii) quantitative measurements of radioactivity (molar ratios) indica...
Osiyemi TI, Synge EM, Agbonlahor DE, Agbavwe R.Toxoplasma gondii antibodies were found in the sera of 22.86% of people in the Jos area of Plateau State, Nigeria. The incidence of antibodies in Nigerian food animals was 17.40%, the highest being in sheep (21.92%) and lowest in goats (13.88%). Cattle and horses were roughly equally infected--about 17.0%. The zoonotic potential of T. gondii in food animals is stressed and epidemiological factors are reviewed.
Broström H, Hellström U, Hammarström S, Obel N, Perlmann P.Untreated and neuraminidase-treated equine peripheral blood lymphocytes were analysed for binding of the A hemagglutinin of the snail Helix pomatia (HP). For optimal staining by direct immunofluorescence, the concentration of neuraminidase had to be increased as compared to that needed for other species. Moreover, higher concentrations of HP were required for optimal staining of equine lymphocytes as compared to lymphocytes from other species. Even so, the maximal number of equine lymphocytes exhibiting positive staining was only about 20%. No, or very few, HP-positive lymphocytes were seen wh...
Brownlow MA.Cells in the peritoneal fluid from 179 horses were examined in Giemsa stained preparations using light microscopy. Neutrophils were found in all samples whether transudative or exudative although their proportions varied enormously. They were well preserved in "normal" or sterile effusions and hardly differed morphologically from those seen on a peripheral blood film although hypersegmentation was commonly observed. In purulent effusions a reliable correlation was found between degenerative changes in neutrophils such as karyolysis and karyorrhexsis and the presence of toxin-producing microorg...
Rigg DL, Ramey DW, Reinertson EL.Respiratory distress and laryngeal paralysis were found to be caused by a Streptococcus equi abscess of cranial mediastinal lymph nodes, putting pressure on the trachea at the thoracic inlet. Surgical drainage was required to relieve the compression, and long-term antibiotic therapy was used to treat the bacterial infection. The trachea returned to normal diameter but left laryngeal hemiplegia persisted. Peritracheal abscesses should be considered in the differential diagnosis of inspiratory dyspnea of the horse.
McGorum BC, Railton DI, Clarke CJ, Dixon PM, Woodman MP, Long KJ.Hydatid cysts (metacestode of Echinococcus grunulosus) are a
common incidental post-mortem finding in horses in the United
Kingdom (Cranley 1982), being found most frequently in the liver
and the lungs (Schwabe 1986). However, hydatid cysts are well
tolerated by horses and clinical hydatidosis is rare, even in
heavily infected animals (Thompson and Smyth 1975; Thompson
and Allsopp 1988). Clinical disease has been attributed to hydatid
cysts in the equine retrobulbar region (Bamett et ul. 1988), brain
(Gordon 1974, quoted by Thompson 1977) and liver (Barvaux
and Derzelle 1947). This is...
Sinclair R, Binns MM, Chirnside ED, Mumford JA.The N-terminal fragment comprising residues +1 to +50 (gB1-50) of equine herpesvirus type 1 (EHV-1) glycoprotein B was expressed as a glutathione S-transferase fusion protein in Escherichia coli. Recombinant gB1-50 (rgB1-50) was recognized in immunoblots by sera from rabbits immunized with EHV-1 and by convalescent-phase sera from horses with natural EHV-1 infections. An enzyme-linked immunosorbent assay (ELISA) for monitoring antibody levels against EHV-1 was developed by using rgB1-50, and its specificity was assessed with a panel of reference antisera against other equine viruses. A specifi...
Van Amstel SR, Ross M, van den Bergh SS.A case of maduromycosis mycetoma caused by Madurella mycetomatis is reported. The horse presented with multiple subcutaneous swelling over the right scapula. There were no discharging fistulae present. Macroscopically the lesion contained a black granular material embedded in a granulomatous mass. Microscopically large numbers of microcolonies were present containing segmented hyphae. No typical chlamydospores were observed. Cultures yielded a fungus identified as Madurella mycetomatis. Treatment consisted of surgical excision and local treatment with thiabendazole powder.