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.
Ferguson JA, Reeves WC, Hardy JL.Serologic studies in 24 ponies indicated that prevaccination antibodies to Venezuelan equine encephalomyelitis (VEE) virus (strain TC-83) had no influence on hemagglutination-inhibition (HI) antibody stimulation by western equine encephalomyelitis (WEE) or eastern equine encephalomyelits (EEE)-WEE vaccines. However, studies of the effects of VEE neutralizing antibodies on neutralizing antibody stimulation by the heterologous alphavirus vaccines were inconclusive. The VEE, WEE, and EEE antibody responses were studied in 18 VEE-vaccinated (strain TC-83) animals (13 ponies and 5 horses) at 9 to 1...
Hadlow WJ, Ward JK, Krinsky WL.Acute neurologic disease associated with intracranial migration of a first instar larva of a warble fly, Hypoderma bovis (Linnaeus), was observed in a 14-year-old Quarter Horse gelding in western Montana. The disease was characterized by incoordination of gait, circling to the left, head tilt to the right, partial paralysis of the right side of the face, and impaired vision in the right eye. Two and one-half hours after it was first noticed sick, the horse collapsed and was euthanized. Massive hemorrhage unaccompanied by necrosis or significant cellular response was present in the right side o...
Moorthy AR, Spradbrow PB, Eisler ME.Vaginal swabs from 19 mares and penile swabs from 4 stallions were cultured for mycoplasmas. A single semen sample from one of the stallions was also examined. Twelve vaginal swabs and 2 penile swabs yielded mycoplasmas. Ten of the positive vaginal swabs were from mares with vaginitis, or with a history of failure of conception. Two were from apparently healthy mares, but one had been served by an infected stallion. One positive penile swab was from a stallion with ulcerative lesions and the other from a stallion with breeding difficulties. All 14 strains of mycoplasma utilised arginine, and t...
Slocombe JO, Rendano VT, Owen RR, Pennock PW, McCraw BM.Radiographs of the aorta and abdominal arteries were obtained from a normal anesthetized pony following catheterization of a femoral artery for nonselective, semiselective or selective arteriography. The arteries had smooth borders and regular diameters and the branches of the cranial mesenteric artery could be followed distally on the angiogram through to the smaller branches proximal to the bowel wall. Following arteriography, the pony walked normally and there were minimal alterations of the levels of serum muscle enzymes and blood lactate. The procedures for arteriography were repeated in ...
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 ...
Mitchell KF, Karush F, Morgan DO.The heterogeneity of the IgM response has been studied with anti-lactose antibody purified from the sera of seven horses. The IgM antibody was induced with a bacterial vaccine and the sera were obtained during a one-year period of immunization. L and H chain preparations were derived from separate bleedings of each horse and examined by analytical isoelectric focusing. All of the L chain preparations were complex and similar and, under optimum conditions, exhibited about 45 bands. Their similarity included almost identical concentration distributions over the entire pH gradient. Isoelectric ba...
Cimprich RE, Rooney JR.Corynebacterium equi is a pathogen associated with respiratory disease in the foal. This paper discusses two cases of Corynebacterium equi infection, one acute and one chronic, in which the major damage was intestinal. Necrosis of Peyer's patches was the only lesion seen in the small intestine of both foals. The foal with acute disease had distinct green-tan focal necrosis and thickened mucosa of the large intestine. In the foal with chronic disease, the mucosa of the large intestine was thickened, rugose, and mottled red-tan. Histologically, the predominant lesions were villous atrophy, mucos...
McGavin MD, Knake R.A 35-kg Duroc pig died 3 days after eating a ration containing aflatoxin B1, B2, G1, and G2. It had hemorrhagic enteritis and extensive midzonal necrosis in the liver. A 13-year-old Quarterhorse that died 2 days after eating moldy hay had hemorrhagic enteritis, fatty degeneration of the myocardium and renal tubules, and extensive total midzonal necrosis of the liver.
Gaskin JM, Neal FC, Rubin HL.Precipitin lines not associated with equine infectious anemia (EIA) were observed in routine agar gel immunodiffusion (AGID) testing for the infection. The serums which produced these lines were obtained from horses which had been given multiple vaccinations with commercially available cell culture-origin equine virus vaccines as part of a comprehensive herd health program. The lines formed against cell culture-derived, but not spleen-derived EIA viral antigens. Investigation revealed that bovine serum proteins in the vaccines induced precipitating antibodies which reacted with bovine serum pr...
Wheeldon EB, Greig WA.The history, clinical signs and post mortem findings in a case of Globidium leuckarti infection in a horse with chronic diarrhoea are described. The limited literature concerning this infection is reviewed, with particular reference to pathogenicity.
Mirzayans A, Maghsoodloo H.Microfilariae of three genera, namely Elaeophora böhmi, Onchocerca cervicalis and Parafilaria multipapillosa were recovered from blood samples of equidae in Tehran, Iran. These microfilarial infections in equidae are reported for the first time from Iran.
Gard GP, Marshall ID, Walker KH, Acland HM, Saren WG.An outbreak of Murray Valley encephalitis (MVE) occurred in New South Wales during the first five months of 1974. Specimens from 52 horses with nervous disease collected January to May 1974 were examined histopathological or virologically. Although MVE virus was not isolated, 13 horses had serological evidence of recent infection with MVE virus. Another 4 horses had evidence of recent infection with Ross River virus. Two animals had histological evidence of viral infection of the central nervous system. Attempts to experimentally infect 2 horses with a low dose of MVE virus were not successful...
Ardans AA, Trommershausen-Smith A, Osburn BI, Mayhew IG, Trees C, Park MI, Sawyer M, Stabenfeldt GH.Immunotherapy was attempted in 2 Arabian foals with combined immunodeficiency. One foal was given a transplant of bone marrow from a selected full sibling, and 1 foal was given a fetal thymus transplant. Both foals died. Genetic evidence was obtained for survival of the transplanted tissues in both cases; however, a graft versus host reaction developed in the foal given the fetal thymus transplant.
Perryman LE, McGuire TC, Hilbert BJ.Selective immunoglobulin M deficiency was diagnosed in 5 foals, on the basis of reduced serum immunoglobulin M concentrations (more than 2 standard deviations below the normal mean). All 5 foals had clinical signs or lesions involving the respiratory tract. Lkebsiella sp was isolated from joint fluids, bronchial lymph nodes, or tracheal washings from the 3 foals in which such samples were available for microbiologic evaluation.
Kakas R, Stockdale S, Carr A.The research article discusses a case study of a young boxer diagnosed with septic physitis of the humerus, and the MRI findings observed which assisted in identifying the condition. Introduction […]
Watanabe R, Furuta H, Ueno Y, Nukada T, Niwa H, Shinyashiki N, Kano R.Trichophyton bullosum is a zoophilic dermatophyte that has been rarely isolated from horses and humans in Africa and Europe. This is the first reported isolation of T. bullosum from a horse with dermatophytosis in Japan. The isolate from a skin lesion formed a cream-colored and waxy colony that was slightly elevated in the center. Sequencing of the internal transcribe spacer region of the isolate revealed that it was 100% identical to that of T. bullosum.
Lotstra RJ, van den Broek J, Power T, Marr CM, Wijnberg ID.Atrial fibrillation is a common equine arrhythmia. Quinidine alone, or with digoxin are common treatments. Studies on outcome in Warmblood populations in which duration of the AF is often unknown are limited. Objective: To identify the factors that are associated with the success of full treatment cardioversion with oral medication, and establish whether there are differences in these factors between institutions. Methods: Retrospective case series using patient records of Equine University Clinic of Utrecht University and Rossdales Equine Hospital, Newmarket. Methods: Forty-nine horses treate...
Wood AL, Spradbrow PB.Fetal equine fibroblasts exposed to bovine papillomavirus became transformed by the criteria of morphological alterations and the acquisition of an increased life span, although they failed to grow in soft agar. Papillomavirus genome persisted in the transformed fibroblasts and was apparently not integrated with the cellular genome. These findings support the notion that bovine papillomaviruses are involved in the production of equine sarcoids.
Gibson KT, Burbidge HM.Three horses were presented for treatment of chronic infections of the digital flexor tendon sheath. Clinical signs included severe lameness, and heat, pain and swelling of the digital flexor tendon sheath. The horses were treated with surgical lavage of the tendon sheath, systemic and local antibiotics, and analgesics. In each case, resolution of the lameness occurred over weeks to months. Only one horse returned to athletic activity, while the other two became comfortable at pasture. Response to treatment in cases of chronic tenosynovitis may not be as rapid or complete as that reported for ...
Anderson WI, Picut CA, Georgi ME.Heavy renal infection in a pony with Klosiella equi resulted in moderate diffuse tubular nephrosis and tubular rupture. Multifocal non-suppurative interstitial nephritis was associated with ruptured tubules. Ultrastructural examination of sporoblasts demonstrated both the presence of a bilaminated membrane encasing organisms and nuclear budding. Endogenous corticosteroid production probably led to the development of an immune-compromized state and subsequent extensive parasitic replication.