The study of diseases in horses encompasses a wide range of conditions affecting equine health, including infectious diseases, metabolic disorders, and genetic abnormalities. These diseases can impact various systems within the horse, such as respiratory, gastrointestinal, and musculoskeletal systems, and can lead to significant health challenges. Research in this area focuses on understanding the pathophysiology, diagnosis, prevention, and treatment of equine diseases. Common diseases studied include equine influenza, equine herpesvirus, and laminitis. This page provides access to peer-reviewed research studies and scholarly articles that explore the etiology, clinical presentation, and management strategies of diseases in horses, contributing to the advancement of equine veterinary medicine.
Cheung AT, Liu IK, Walsh EM, Miller ME.The host defense competence of uterine-derived polymorphonuclear leukocytes (PMN) from mares considered resistant (grade I uteri) and susceptible (grade III uteri) to chronic endometritis was evaluated for phagocytic and killing (bactericidal) capacities, using a fluorochrome assay. Peripheral blood PMN from noncategorized mares and from grade I and grade III mares were used as controls. Uterine-derived PMN from mares with grade I uteri were functionally competent for phagocytosis and killing of Candida albicans, whereas uterine-derived PMN from mares with grade III uteri had significantly les...
Dubey JP.Thirteen 6-month- to 13-year-old equids were each inoculated orally with 10,000 infective Toxoplasma gondii oocysts. The equids remained clinically normal. Equids were euthanatized on postinoculation days 33, 45, 90, 104, 120, 140, 162, 183, 197, 204, 211, 294, and 476. Their tissues were bioassayed for viable oocysts by feeding muscles to Toxoplasma-free cats and by inoculation of pepsin digests of 13 organs into mice. Using mouse inoculation, T gondii was recovered from tissues of the 9 equids euthanatized on each of postinoculation days 33, 45, 120, 140, 183, 197, 211, 294, and 476. Toxopla...
Markel MD, Meagher DM, Ford TS.A 3-month-old Quarter Horse filly stepped on a fence staple and developed navicular bone osteomyelitis of the right hindfoot. A 1.5-cm spherical portion of medullary cavity containing purulent material was debrided and flushed with 0.9% NaCl solution. Cancellous bone was collected from a caudal sternebra and placed into the defect. The solar defect had filled with granulation tissue and was epithelialized 6 weeks after surgery. At 6-month follow-up evaluation, the navicular bone defect had healed and the foal was sound on the limb. Cancellous bone grafting may have merit for the treatment of n...
Beetson SA, Hilbert BJ, Mills JN.The effectiveness of the glutaraldehyde coagulation test (GCT) in detecting failure to acquire colostral immunoglobulin in neonatal foals was investigated. This was achieved by comparing and correlating results from the GCT with those obtained by single radial immunodiffusion (SRID) of equine IgG. The GCT was found to be a practical, inexpensive, semiquantitative test with a high specificity and sensitivity at critical IgG levels.
Slocombe JO.This review summarizes information on the clinical signs, gross and microscopic lesions associated with nematode and cestode infections and discusses the development of these conditions in the equine host.
Ross MW, Martin BB, Donawick WJ.The case records of 23 horses with cecal perforation (CP) were reviewed. The horses averaged 4.5 years of age (6 weeks to 13 years) and included 9 intact males, 12 mares, and 2 geldings. Twelve of the horses were Standardbreds, 9 were Thoroughbreds, and 1 each, a Belgian and Morgan. The horses were allotted to 2 groups: group I-13 hospitalized horses in which CP occurred unexpectedly, and group II-10 horses with CP at the time of admission. The horses characteristically had been sick or affected with disease unrelated to the cecum. Sixteen horses had been given nonsteroidal anti-inflammatory d...
Farrar RG, Klei TR.Strongylus edentatus was successfully cultured in vitro to the fourth larval stage (L4). Some growth continued for periods of 40-50 days at which time reductions in viability were observed in some of the culture systems tested. Various combinations of media, sera, buffers and organ explant cultures were tested. All cultures were incubated at 37 C in an atmosphere of 95% air and 5% CO2. Larvae underwent growth and differentiation to the L4 in all medium-serum combinations with and without organ explant cultures. Development and growth did occur but viability was reduced to insignificant levels ...
Kirkpatrick CE, Skand DL.Giardia infection was believed responsible for chronic diarrhea, weight loss, lethargy, inappetence, and dermatitis in a 4-year-old Thoroughbred horse. Fecal cysts were detected by the zinc sulfate centrifugal flotation method. All clinical signs resolved upon treatment with metronidazole suspension (5 mg/kg body weight per os, TID for 10 days).
Spier S.A 3-day-old foal was examined because of forelimb lameness. Brachial artery occlusion was diagnosed. The foal was euthanatized. Necropsy revealed brachial artery thrombosis and an atrial septal defect.
Auer DE, Wilson RG, Groenendyk S, Kalhoro A, Wilson RP.THE diagnosis of a diaphragmatic rupture in the horse is
usually made at exploratory laparotomy or necropsy. Of the 18
cases reviewed by Wimberly, Andrews and Haschek (1977) a
diagnosis was made by clinical examination only three times.
Most cases are presented because of abdominal pain and, of
these, about one third have a history of colic (Wimberly et al
1977). Respiratory difficulty, depression and recumbency may
be other presenting signs but these occur less frequently.
Chronic diaphragmatic hernias have been diagnosed at
autopsy in horses showing no clinical signs attributable to...
Davies ME, Bingham RW.Two morphological types of spirochaete were found in the horse caecum measuring 4 to 6 micron by 0.3 to 0.4 micron and 6 to 8 micron by 0.1 to 0.2 micron. Attempts were made to culture the organisms but none survived subculture beyond the primary isolate. Electron microscopy revealed that many of the organisms were infected by bacteriophages.
Buergelt CD, Cooley AJ, Hines SA, Pipers FS.Six horses (five males) aged three months to fourteen years had endocarditis at necropsy. Two of the horses had a clinical diagnosis of valvular endocarditis with negative blood cultures. Single or complex valvular involvement was present in five horses. One horse had non-infectious thrombi associated only with the chordae tendineae. Mitral valves were affected in four horses, and aortic semilunar valves were affected in two. Infarcts had occurred in the kidneys and the myocardium of four horses. Bacteria were isolated postmortem from the valvular vegetations of two horses; Candida parapsilosi...
Cahill JI, Goulden BE, Pearce HG.A review of the literature on stringhalt in horses is presented, including the aetiology, clinical signs, pathology and treatment of this disease. Three New Zealand outbreaks of stringhalt are reported and discussed. The occurrence of these (and most previously reported outbreaks) in the late summer and autumn, and the association of the disease with various weeds, indicates a likely toxic aetiology.
Lazary S, Gerber H, Glatt PA, Straub R.The distribution of equine leucocyte antigens (ELA) in horses affected by equine sarcoid tumours was determined and compared with unaffected controls. ELA-haplotype W3,B1 occurred more frequently in affected riding horses of Irish, Swiss and French background. The combined data for the three breeds resulted in a chi 2 value of 20.35 (P less than 0.0005 after correction). Simultaneously, ELA-specificity W11 was more frequently found in horses of Irish background, while W5 was found in Swiss and French horses with sarcoids. The combined data for haplotype W3,B1 and/or W5 specificity demonstrated...
Blythe LL, Mattson DE, Lassen ED, Craig AM.Neutralizing antibodies against equine herpesvirus 1 were measured in serum and cerebrospinal fluid of 16 horses and ponies from a closed herd both before and after vaccination with modified live equine herpesvirus 1. These titers were also measured in 22 neurologically normal and 15 neurologically abnormal horses at a teaching hospital. Animals from the closed herd had prevaccination serum titers up to 1:8 and postvaccination serum titers up to 1:128. Horses from the teaching hospital had serum titers up to 1:64. Cerebrospinal fluid titers were not detected in the vaccinated horses or the neu...
Ainsworth DM, Dodds WJ, Brown CM.A 16-year-old gelding was examined because of weight loss, inappetence, and intermittent fever of 2 months' duration. Preliminary laboratory findings revealed anemia, hypoproteinemia, thrombocytopenia, and prolongation of the activated partial thromboplastin time. A deficiency or inhibition of coagulation factor XI, factor XII, or high molecular weight kininogen was diagnosed. This defect was not associated with a bleeding diathesis, but should be considered as a cause of prolongation of the activated partial thromboplastin time.
Wilson WD, Hughes SJ, Ghoshal NG, McNeel SV.Occipitoatlantoaxial malformation was diagnosed in a 19-month-old mare of Appaloosa breeding and in a 3-year-old Quarter Horse gelding. Both horses had abnormal head and neck carriage since birth, but neurologic deficits did not become evident clinically until the horses reached 2 and 3 years of age, respectively. Palpation and manipulation of the base of the skull and cervical area proved to be useful diagnostically. Movement could not be elicited at the atlantooccipital joint but, in comparison with clinically normal horses, the range of dorsoventral motion at the atlantoaxial joint was incr...
Gabal MA, Mohammed KA.An enzyme-linked immunosorbent assay was evaluated for the detection of antibody in sera of equine naturally infected with Histoplasma farciminosum 'epizootic lymphangitis'. Ten sera from naturally infected horses were tested. A hydrogen peroxide ABTS mixture constituted the substrate. The reactions were read as the absorbance values measured at 405 nm using a spectrophotometer. The standard deviation and the average percentage of the absorbance values of the different serum samples were considered in the interpretation of the results. All sera were proved positive with variations in the diffe...
Kirker-Head CA, Loeffler D, Held JP.Malignant melanoma in a 21-year-old, gray, Arabian gelding was manifested by rapidly deteriorating lameness of the right pelvic limb. A melanotic, cutaneous mass of small dimensions was identified in the left jugular furrow. Exploratory laparoscopy revealed widespread infiltration of melanotic masses into the structures of the abdominal cavity. Necropsy indicated the lameness to have resulted from infiltration of neoplastic cells into the sacral nerves, dorsal root ganglia, proximal ischiatic nerve, and gluteal muscle fibers. The primary tumor could not be identified.
Sims LD, Tzipori S, Hazard GH, Carroll CL.Two foals aged 35 and 48 h from 2 Thoroughbred studs died several hours after developing clinical signs of depression, severe haemorrhagic diarrhoea and dehydration. Both foals had an acute haemorrhagic enteritis extending from the anterior jejunum to the terminal ileum which was characterised histologically by villus necrosis. Necrotic villi were surrounded by large numbers of rod-shaped Gram positive bacteria. Clostridium perfringens was recovered from the intestines of both foals and the isolates were considered to be C. perfringens type C. Other cases of diarrhoea were also observed in foa...
Adamson PJ, Jang SS.Salmonella arizonae 61:1,5, was isolated in pure culture from the eye of a horse with unilateral ulcerative keratitis. The eye responded well to treatment with atropine sulfate and polymyxin B-bacitracin-neomycin ophthalmic ointments. In swab specimens taken after the lesion had healed, Salmonella was not found to be a constituent of the bacterial flora of the horse's eyes.
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...
Moorman VJ, Jann HW.A 2-day-old Thoroughbred intact female was presented for a large subcutaneous swelling in the right inguinal region. Surgical repair was performed using a double layer polypropylene mesh. To the authors' knowledge, there have been no previous reports of surgical repair of congenital body wall hernias with polypropylene mesh in foals. Une femelle pur sang intacte âgée de deux jours est présentée pour de l’enflure sous-cutanée importante dans la région inguinale droite. Une réparation chirurgicale est réalisée en utilisant une double couche de maille de polypropylène. À la connaiss...
Birks EK, Hultgren BD.A primary pericardial haemangiosarcoma with metastasis to the parietal pleura and left adrenal gland is described in a 22-year-old Clydesdale x Percheron gelding. Although haemangiosarcomas have been reported in horses, the pericardium has not hitherto been described as the primary site of origin.
Tallmadge RL, Antczak DF, Felippe MJB.Host defenses against infection by viruses, bacteria, fungi, and parasites are critical to survival. It has been estimated that upwards of 7% of the coding genes of mammals function in immunity and inflammation. This high level of genomic investment in defense has resulted in an immune system characterized by extraordinary complexity and many levels of redundancy. Because so many genes are involved with immunity, there are many opportunities for mutations to arise that have negative effects. However, redundancy in the mammalian defense system and the adaptive nature of key immune mechanisms bu...