Disease diagnosis in horses involves the identification and characterization of illnesses through various diagnostic methods and tools. This process is essential for effective veterinary care and management of equine health. Techniques used in diagnosing diseases in horses include clinical examinations, laboratory tests, imaging modalities such as ultrasonography and radiography, and molecular diagnostics. Blood tests are frequently utilized to assess parameters such as complete blood count and biochemical profiles, which can indicate underlying health issues. Additionally, advancements in genetic testing and biomarker identification have enhanced the ability to detect specific diseases early. This page aggregates peer-reviewed research studies and scholarly articles that explore diagnostic methodologies, their applications, and their impact on equine health management.
Madić J, Hajsig D, Sostarić B, Curić S, Seol B, Naglić T, Cvetnić Z.An abortion outbreak occurred in a herd of 38 horses, 26 of which were pregnant mares. Twenty-one mares aborted between 5-10 months of gestation. In no case were there indications of impending abortion. Pathoanatomical, histopathological, virological and bacteriological examinations were carried out on 4 aborted fetuses. Histopathology identified Gram-negative bacteria compatible with salmonella in all 4 placentae. By subsequent bacteriological examination Salmonella abortusequi was isolated as the single causative agent in each case. Nonmotile Salmonella abortusequi with antigenic formula 4,1...
Sailleau C, Moulay S, Cruciere C, Laegreid WW, Zientara S.A reverse transcription-polymerase chain reaction (RT-PCR) assay followed by dot-blot hybridisation was used to detect African horse sickness virus (AHSV); the primers employed amplified the S7 gene that encodes the VP7 protein. The RT-PCR assay was compared with virus isolation for detecting AHSV in blood samples form horses experimentally infected with AHSV-4 and AHSV-9. The influence of sample storage and transportation and the effects of two anticoagulants (EDTA and heparin) were also studied. RT-PCR results were obtained within 48 hours as opposed to a minimum of 15 days for virus isolati...
Machida N, Taniguchi T, Nakamura T, Kiryu K.Twenty-five aborted equine fetuses infected with equid herpesvirus 1 (EHV-1) were examined cardio-histopathologically. The main changes in the heart consisted of interstitial myocarditis and intramyocardial vascular lesions accompanied by degeneration and necrosis of the cardiac myocytes. Vascular pathology of intramyocardial small arteries and arterioles was characterized by endothelial cell necrosis and fibrinoid changes in the media. Eosinophilic intranuclear inclusion bodies characteristic of herpesvirus infection were detected in the myocardial cells and macrophages within and around the ...
Sarkar P, McIntosh JM, Leavitt R, Gouthro H.Nimesulide is a nonsteroidal anti-inflammatory drug recently detected in equine blood and urine samples taken at the race track. The detection of the drug in a blood sample led to the identification of an unknown thin-layer chromatographic (TLC) spot in track urine samples as a metabolite of nimesulide. Characterization of the unknown TLC spot and comparison with the synthesized compound shows that the unknown TLC spot is a previously unreported equine metabolite of nimesulide. The metabolite was identified as resulting from the reduction of the nitro group on nimesulide to an amino group. Thi...
Birch-Machin I, Rowan A, Pick J, Mumford J, Binns M.The nucleotide sequence of the nonstructural protein NS1 of the influenza virus A/equine 2/Suffolk/89 was determined and found to be 97% identical to that of A/equine 2/Miami/63. A similar level of identity was shown for the deduced NS1 amino acid sequence. The NS1 gene was expressed, in its entirety and in part, as fusion proteins with glutathione S-transferase using the pGEX-3X expression vector. Antibodies to NS1 protein were detected in serum samples from ponies experimentally infected with influenza virus, but not in animals vaccinated with whole inactivated virus or in unprimed control a...
Hobo S, Oikawa M, Kuwano A, Yoshida K, Yoshihara T.To study the effects of extended transportation on the composition of bronchoalveolar lavage fluid (BALF) obtained from horses. Methods: 30 horses (14 males, 16 females: 25 Thoroughbreds and 5 Thoroughbred-Arabian cross-breds; 27 to 30 months old) without a history or clinical signs of respiratory tract disease. Bronchoalveolar lavage was performed on nontransported control horses (groups 1 and 2) and transported horses (group 3). Methods: 20 horses were used to determine the effect of 41 hours of transportation on the composition of BALF (group 3). Bronchoalveolar lavage fluid was analyzed fo...
Kilic S, Dixon PM, Kempson SA.Ultrastructural examinations showed the diameter of cement lacunae to be greater in infundibular cement than in peripheral cement of upper cheek teeth, which in turn was greater than in the peripheral cement of the lower cheek teeth. However, numbers of lacunae/unit area remained similar in these 3 dentinal region. Two types of cemental hypoplasia were found in equine cheek teeth. The first type was termed central infundibular cemental hypoplasia and was confined to the central region of infundibular cement. The cement adjacent to these frequently large defects was very porous and contained la...
Byrne KM, Davis WC, Holmes MA, Brassfield AL, McGuire TC.Two monoclonal antibodies (MAb), HB65A (IgG2a) and HB86A (IgGI), recognize a unique cell surface molecule on equine T-lymphocytes. The molecule, designated EqWC4, identified by these MAbs is present on a subpopulation of CD4+ equine lymphocytes (6.3-10.2% of Arabian lymphocytes CD4+ WC4+) and a smaller population of CD8+ lymphocytes (0.5% to 1.2% of Arabian lymphocytes CD8+ WC4+). EqWC4 is absent from B-lymphocytes, granulocytes, and macrophages. Both MAbs bound to a 46-kDa protein following immunoprecipitation reactions with lysates of surface labeled thymocytes. Immunoaffinity purification u...
Valentine BA, Credille KM, Lavoie JP, Fatone S, Guard C, Cummings JF, Cooper BJ.A severe myopathy leading to death or euthanasia was identified in 4 Belgian and 4 Percheron draught horses age 2-21 years. Clinical signs ranged from overt weakness and muscle atrophy in 2 horses age 2 and 3 years, to recumbency with inability to rise in 6 horses age 4-21 years. In 5 horses there was mild to severe increases in muscle enzyme levels. Clinical diagnoses included equine motor neuron disease (2 horses), post anaesthetic myopathy (2 horses), exertional myopathy (2 horses), myopathy due to unknown (one horse), and equine protozoal myelitis (one horse). Characteristic histopathology...
Uhlir C, Licka T, Kübber P, Peham C, Scheidl M, Girtler D.In order to study the mechanism of lameness transfer from fore- and hindlimb lamenesses 2 hypotheses were investigated. Hypothesis 1: Horses with a true supporting limb lameness in one hindlimb show a false supporting limb lameness in the ipsilateral forelimb. Hypothesis 2: Horses with a true supporting limb lameness in one forelimb show a false supporting limb lameness in the contralateral hindlimb. Fourteen horses with fore- or hindlimb lameness were used for this study. Each horse was measured at the trot on a treadmill with standardised speed, before and after diagnostic blocks (9 horses),...
Bayly WM, Slocombe RF.Effects of respiratory tract obstructions on ventilatory mechanics in horses exercising at high speeds were tested with a fibreglass replica of the airways (nares to mainstem bronchi) of an adult horse. Segmental pressures were recorded at six sites along the model at four different unidirectional flows (1300-4100 litre min-1), and the respective resistances (R) to airflow were calculated. The external nares and the larynx made the greatest contributions to the total resistance (RTOT) when no obstruction was present. Modifying the model to simulate severe pharyngeal lymphoid hyperplasia (PLH) ...
Kumar S, Malhotra DV, Dhar S.The present study aimed to develop Dot-ELISA, complement fixation test (CFT) and capillary tube agglutination test (CAT) for serodiagnosis of Babesia equi infection and to compare their sensitivity with each other. For this study, sequential serum samples were collected from four donkeys experimentally infected with B. equi up to 90 days post infection (P.I.). B. equi antigen was prepared from the blood of a donkey showing more than 80% parasitaemia. Dot-ELISA, CF and CA tests were standardized as per the standard method. While performing CFT, it was observed that CFT standardized for the donk...
Rizvi SM, Slater JD, Wolfinger U, Borchers K, Field HJ, Slade AJ.The distribution of equine herpesvirus 2 (EHV-2) DNA within neurological and lymphoid tissues from 12 EHV-2 seropositive Welsh mountain ponies was determined by PCR. The lymphoid sites sampled in this study were almost universally PCR positive, thus confirming the existing virus co-cultivation data which suggest that the lymph nodes draining the respiratory tract are the main reservoirs of EHV-2 DNA. In addition, EHV-2 DNA was also detected, albeit with lower frequency, within both the peripheral and central nervous systems (PNS and CNS) of these animals. Of the CNS sites sampled 11% were PCR-...
Smith KC.Abortion or neonatal disease may follow infection with several alpha, beta and gamma-herpesviruses. The alpha-herpesvirus, equid herpesvirus-1 (EHV-1), causes single or epizootic abortions or neonatal deaths in equids, and the closely related virus EHV-4 causes sporadic equine abortions. In cattle, the alpha-herpesviruses, bovine herpesvirus-1 (infectious bovine rhinotracheitis virus) and bovine herpesvirus-5 (bovine encephalitis virus), and a gamma-herpesvirus, bovine herpesvirus-4, have all been implicated as causes of abortion. In pigs, suid herpesvirus-1 (SHV-1: pseudorabies virus), an alp...
Gu X, Meleka-Boules M, Chen CL, Ceska DM, Tiffany DM.A capillary electrophoresis (CE) and a solid-phase extraction method was developed for the determination of flunixin in equine urine and serum. The suitable CE run conditions were described. The factors affecting flunixin recovery rates were investigated and optimum solid-phase extraction conditions for flunixin in equine urine and serum were established. Limits of detection and quantitation were 3.4 and 5.6 ng/ml for serum and 16.9 and 33.1 ng/ml for urine, respectively. The recoveries exceeded 96% for urine and 79% for serum. Urine samples from race horses and urine and serum samples from a ...
Birkett AJ, Yélamos B, Rodríguez-Crespo I, Gavilanes F, Peterson DL.The gene coding for the major core protein (p26) of the lentivirus equine infectious anemia virus (EIAV) was cloned from EIAV infected serum, expressed in E. coli, and the resultant protein purified to electrophoretic homogeneity. The protein was expressed in a soluble form and was purified by conventional protein separation methods. When analyzed by SDS-PAGE, under both reducing and non-reducing conditions, the purified protein migrated as a 26 kDa monomer. Recombinant p26 (rp26), therefore, does not contain any intermolecular disulfide bond. Gel filtration chromatography also indicated that ...
Shin EK, Perryman LE, Meek K.The equine SCID defect is more severe than its murine counterpart in that SCID foals are incapable of forming either coding or signal joints, whereas SCID mice manifest normal signal joint formation. To determine the basis of this difference and whether DNA-dependent kinase, catalytic subunit (DNA-PK(CS)), is involved in signal joint formation, equine DNA-PK(CS) transcripts were cloned and sequenced from normal and SCID cell lines. In the mutant allele, a frame-shift mutation truncates the protein N terminal of the domain with homology to the phosphatidylinositol 3-kinase family resulting in c...
Parlevliet JM, Bleumink-Pluym NM, Houwers DJ, Remmen JL, Sluijter FJ, Colenbrander B.Contagious equine metritis (CEM) is a sexually transmissible disease in mares. Although the disease is commonly diagnosed by culturing the causative bacterium Taylorella equigenitalis (T. equigenitalis) . false negative results do occur. A recently developed Polymerase Chain Reaction (PCR) assay, however, appeared to be much more sensitive, with initial results indicating an unexpected high incidence of the agent in selected horses. In this study, samples from 107 randomly selected mares with no clinical signs of CEM submitted for conventional culture were all negative for T. equigenitalis . b...
Tschetter JR, Byrne KM, Perryman LE, McGuire TC.Horses infected with equine infectious anemia virus (EIAV) have recurrent episodes of viremia which are eventually controlled, but the immune mechanisms have not been identified. Antibodies were detected to the surface of EIAV-infected cells within 1 month postinfection and remained for at least 3.5 years postinfection. These antibodies recognized cell surface-exposed envelope (Env) glycoproteins, but could not mediate antibody dependent cellular cytotoxicity (ADCC) using EIAV-WSU5-infected equine kidney (EK) cells as targets and peripheral blood mononuclear cells (PBMC) or polymorphonuclear c...
Wood JL, Chanter N, Newton JR, Burrell MH, Dugdale D, Windsor HM, Windsor GD, Rosendal S, Townsend HG.Lower respiratory tract disease developed in a group of racehorses in training between two and six years of age. Disease was observed in 22 of 25 horses for which full records were available. Seroconversion to Mycoplasma felis was demonstrated by indirect haemagglutination assay in 19 of 22 paired sera and high titres (> or = 64) were found in convalescent sera from the three remaining horses. Evidence of respiratory viral infection was confined to seroconversions to equine herpesvirus-4 in two of the horses. Tracheal wash samples, taken from four horses with visibly increased tracheal muco...
Uhlinger C.Leukoencephalomalacia in horses is caused by fumonisins. These mycotoxins are produced by Fusarium spp. that contaminate corn and corn byproducts while in the field. The most common clinical presentation is a multifocal neurologic disease that affects multiple horses in a herd. Although the majority of affected horses die, treatment directed at decreasing inflammation and edema in the CNS may result in recovery in some animals.
Wilson WD.Myeloencephalopathy is an uncommon manifestation of equine herpesvirus 1 (EHV-1), but it can cause devastating losses during outbreaks on individual farms. Clinical signs of neurologic disease reflect a diffuse multifocal hemorrhagic myeloencephalopathy secondary to vasculitis and thrombosis. Sudden onset and early stabilization of signs, including ataxia, paresis, and urinary incontinence; involvement of multiple horses on the premises; and recent history of fever, abortion, or viral respiratory disease in the affected horse or herdmates are typical features, although there is considerable va...
Beech J.This article presents a brief description of what is known about the cause and pathogenesis of chronic intermittent rhabdomyolysis in horses. Clinically applicable diagnostic tests and published results in affected horses, prophylaxis, and treatment of the acute case are discussed.
Löfstedt J.White muscle disease (nutritional myodegeneration) of foals is a peracute to subacute myodegenerative disease affecting skeletal and cardiac muscle. It is caused by a dietary deficiency of selenium and vitamin E, usually in association with predisposing factors such as a high intake of dietary unsaturated fats or unaccustomed exercise. White muscle disease has been observed in foals from birth to 1 year of age, particularly those foals born to dams fed selenium-deficient diets, during gestation. The disease in foals may present as an acute, fulminant syndrome, which is rapidly fatal, or a suba...
Divers TJ, Mohammed HO, Cummings JF.This article reviews the subject of equine motor neuron disease, a neurodegenerative disease of horses. The authors discuss various topics, including epidemiology, pathophysiology, clinical signs, laboratory findings, diagnosis, and treatment.
Viranta S, Mannermaa K.Development of dental abnormalities due to improper occlusal wear is common among modern domestic horses. This phenomenon often is attributed to jaw conformation. Rostral mandibular hooks may develop in horses with underjet or mandibular prognathism, a condition where the lower jaw protrudes forward, beyond the upper jaw. Less abrasive diet, free of phytoliths and matrix-like plant fibers, also may promote enamel and focal overgrowths of equine dentition. Here we report a rostral mandibular hook in a lower premolar tooth of a medieval horse, found in a spring deposit in Levänluhta, Osthroboth...
Heyneman RA, Bruyninckx WJ, Vercauteren RE.Two distinct groups of acid phosphatase containing granules were characterized in neutrophils, each group displaying different multiple forms of the enzyme. The heavy granule acid phosphatase showed a lysosomal location. A second lighter group of particles contained a thermolabile, thiol-dependent acid p-nitrophenyl and alpha-naphtylphosphatase, an enzyme clearly different from lysosomal acid phosphatase. Acid phosphatase activity from eosinophil leukocytes appeared to be totally associated with the typical eosinophil granules. On mechanical disruption of these particles, an acid phosphatase w...
Huggons NA, Bell RJ, Puchalski SM.We compared the information gained from computed tomography (CT) vs. radiography in horses with nonneoplastic disease of the mandible. We hypothesized that CT would provide additional diagnostic information. Medical records, radiographs, and CT images of horses with nonneoplastic mandibular disease evaluated between 1994 and 2008 were reviewed. Nineteen horses were identified; 11 had a tooth root abscess and related disease, four had a fracture of the teeth and/or mandible, and four had a nonneoplastic mass. Both CT images and radiographs allowed identification of diseased teeth that appeared ...
Siwinska N, Zak A, Slowikowska M, Paslawska U.Reliable and simple tests are constantly being sought to enable the quick detection of acute kidney injury in humans and animals. Diagnosis of subclinical AKI in horses, mainly in field practice, is difficult. An ultrasound scan is a routine test performed when kidney disease is suspected. The aim of the study was to establish the value of the renal resistive index (RRI) in intrarenal arteries in horses with clinical AKI and compare it to that of healthy horses. The second goal was to determine whether potentially nephrotoxic agents can influence RRI. The kidney ultrasonography examination was...
Campbell-Beggs CL, Kiper ML, MacAllister C, Henry G, Roszel JF.Esophagoscopy allowed visualization and biopsy of a lesion within a diverticulum of the esophagus in an adult horse. Although the biopsy specimen obtained was small, diagnosis of squamous cell carcinoma was possible from histologic examination of the esophageal tissue sample retrieved by use of endoscopy.
Hinckley KA, Fearn S, Howard BR, Henderson IW.The present study applies near infrared spectroscopy (NIRS) to the haemodynamics of the pedal circulation in normal and laminitic horses. NIRS is a noninvasive technique which uses changes in light absorption at 4 wavelengths to provide information on the changes in cytochrome aa3 (cyt aa3) reduction-oxidation (redox) status, and changes in the tissue concentration of oxyhaemoglobin (O2Hb), deoxyhaemoglobin (HHb) and therefore total haemoglobin (tHb). Other studies have shown NIRS to be sensitive to changes in tissue oxygenation and perfusion in human cerebral and limb circulation. In this stu...
Chisholm FR.A prolapsed uterus in a mare and the techniques to successfully replace the organ and prevent complications such as shock, laminitis and metritis are described.
Brooks SA, Bailey E.Inflammatory damage to the digital laminae, a structure responsible for suspension of the distal skeleton within the hoof capsule, results in a painful and often life-threatening disease in horses called laminitis. There can be many diverse causes of laminitis; however, previous work in the horse has suggested that in each case, the inflammation and resulting tissue damage is consistent with the action of mediators released from mast cells (MC), as well as the downstream consequences of their activation. The recent development of molecular genetics tools to characterize cells based on their tr...
Scott EA, Todhunter R.In 2 cases of chronic intestinal intussusception in horses, one involved jejunum and the other, ileum. The only clinical signs observed were intermittent colic. Surgery was performed on both horses, with successful outcomes.