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.
Mejdell CM, Jørgensen GH, Rehn T, Fremstad K, Keeling L, Bøe KE.The risk of injuries is of major concern when keeping horses in groups and there is a need for a system to record external injuries in a standardised and simple way. The objective of this study, therefore, was to develop and validate a system for injury recording in horses and to test its reliability and feasibility under field conditions. Methods: Injuries were classified into five categories according to severity. The scoring system was tested for intra- and inter-observer agreement as well as agreement with a 'golden standard' (diagnosis established by a veterinarian). The scoring was done ...
Kim HT, Gim TJ, Lee JH.A 53-year-old man had chronic low back and leg pain for four years without any history of trauma or neurological manifestations. There was a reduction in symptoms after a lumbar epidural block. Two hours later after the procedure, the patient complained of perineal numbness and lower extremity weakness. The neurological evaluation revealed loss of sensation in the saddle area and the posterior aspect of the leg. The deep-tendon reflexes were decreased in the leg. The patient was unable to urinate. The MRI revealed a schwannoma at the S3 level of the sacral spine with cauda equina compression. ...
Aalsburg AM, Erdman MM.Taylorella equigenitalis is the etiologic agent of contagious equine metritis (CEM), a venereal disease of horses. A total of 82 strains of T. equigenitalis isolated in the United States were analyzed by pulsed-field gel electrophoresis (PFGE) after digestion of genomic DNA with restriction enzyme ApaI. Twenty-eight of those strains isolated from horses in the 2009 U.S. outbreak (CEM09) were further analyzed with NotI and NaeI enzymes. When ApaI alone was used for analysis, the 82 isolates clustered into 15 different genotypes that clearly defined groups of horses with known epidemiological co...
Chang Y, Maylin GM, Matsumoto G, Neades SM, Catlin DH.Methods have been developed to screen for and confirm darbepoetin alfa, recombinant human EPO, and methoxy polyethylene glycol-epoetin β (PEG-epoetin β) in horse plasma. All three methods screen samples with an enzyme-linked immunosorbent assay (ELISA) and confirm by liquid chromatography-tandem mass spectrometry (LC-MS/MS). This report focuses on PEG-epoetin β. The ELISA assay was able to detect PEG-epoetin β at 0.02 ng/mL in 50 µL of horse plasma. Many samples had high background levels of immunoreactivity; however, introducing polyethylene glycol 6000 (PEG 6000) into the samples before...
Tamekuni K, Toledo Rdos S, Silva Filho Mde F, Haydu VB, Pacheco RC, Cavicchioli JH, Labruna MB, Dumler JS, Vidotto O.Brazilian spotted fever (BSF) is an emerging disease most likely caused by Rickettsia rickettsii. The objective of the present study was to estimate the seroprevalence of BSF rickettsia infections in equines from six horse farms located in Londrina County, Paraná, Southern Brazil. Six owners of horse farms situated in Cambé, Santa Fé, Guaraci and Londrina municipalities participated in the study. All farms were located in areas where BSF has not been reported. A total of 273 horses were sampled and their sera were tested by indirect immunofluorescence assay (IFA) using R. rickettsii and R. ...
Baldani CD, Nakaghi AC, Machado RZ.Blood and serum samples from 170 horses raised in the Jaboticabal microregion, São Paulo State, Brazil, were collected and tested by microscopic examination of blood smears, indirect fluorescent antibody test (IFAT) and nested polymerase chain reaction (nPCR) for Theileria equi infections. The association among the test results was verified by the McNemar test. During the examination of thin blood smears, parasites were detected in six (3.52%) horses. Anti-T. equi antibodies were detected in 100% sera samples, with titers ranging between 1:80 and 1:5120. The nPCR based on the T. equi merozoit...
Botton SA, Pereira DI, Costa MM, Azevedo MI, Argenta JS, Jesus FP, Alves SH, Santurio JM.Pythium insidiosum is a fungus-like organism present in subtropical and tropical areas, such as Brazil, known to infect humans and various animal species. P. insidiosum is the etiological agent of pythiosis, an emerging and granulomatous disease characterized mainly by cutaneous and subcutaneous lesions in horses, the principal species affected. Accurate diagnosis of pythiosis and identification of its causal agent by microbiological and serological tests can be often difficult and inconclusive principally for horses and humans. The aim of this study was to evaluate the application of the prev...
Horsington JJ, Gilkerson JR, Hartley CA.Equine rhinitis B virus (ERBV) is the single species in the genus Erbovirus, family Picornaviridae. Equine rhinitis B viruses exist in three serotypes and are associated with respiratory disease in horses. Members of the species vary in stability at acid pH. To date there has been discordance in genotype, serotype and acid stability phenotype groupings. To identify capsid regions associated with acid stability, two viruses were serially treated at pH 3.3 to isolate acid-stable mutants. An acid-stable mutant of the prototype acid-labile serotype 1 virus contained a single amino acid change in t...
Crawford A, O'Donnell M, Crowe O, Eliashar E, Smith RK.To report the clinical features of horses with fluid-filled masses associated with the digital flexor tendon sheath (DFTS) and outcome after surgery. Methods: Case series. Methods: Horses (n=10) Methods: Medical records of horses with fluid-filled masses associated with the DFTS were reviewed and the clinical features, diagnostic methods, treatment, histopathology, and outcome reported. Results: Masses were unilateral (7 hind limb, 3 front limb) and in 8 horses were associated with lameness. In 6 horses, lameness improved by >50% with intrathecal DTFS anesthesia, whereas 2 were less positiv...
Brandt S, Tober R, Corteggio A, Burger S, Sabitzer S, Walter I, Kainzbauer C, Steinborn R, Nasir L, Borzacchiello G.In equids, bovine papillomaviruses of type 1 (BPV-1) and less frequently type 2 induce common, locally aggressive skin tumours termed sarcoids. Whereas BPV infection in cattle usually involves the epidermis and is productive in this skin layer, infection in equids is currently thought to be abortive, with virus solely residing as multiple episomes in dermal fibroblasts. Based on recent observations that do not agree with this assumption, we hypothesised that BPV also infects equid epidermis and is active in this skin layer. To test this hypothesis, we conducted a proof-of-principle study on ei...
Dyson SJ, Tranquille CA, Collins SN, Parkin TD, Murray RC.During a pre-purchase examination (PPE) there is always a debate about how clinical findings of the hoof different from ideal should be interpreted in relation to future lameness risk and/or unsuitability of the horse for the potential purchaser. The objectives of this study were to describe and compare external angular measurements, linear ratios and hoof capsule characteristics of non-lame and lame feet. Photographs of feet from 300 horses with foot pain and 25 non-lame horses were analysed. Hoof wall, heel and coronary band angles and hoof wall length and height, weight-bearing length, coro...
Simon V, Dyson SJ.Our purpose was to describe the variation of the radiologic appearance of the carpus of horses of different breeds, discipline, and gender with lameness related to the carpus and control horses, with particular reference to the ulnar carpal bone. Two hundred and eighty-six sets of carpal radiographs from 222 horses were analyzed. Breed, gender, discipline, and cause of lameness were recorded. Chi square tests were used to test for associations between radiologic findings and gender, breed and discipline, to test for associations between different radiologic findings, and to test for associatio...
Davies S, Barber D, Crisman M, Tan R, Larson M, Daniel G.We characterized the scintigraphic and sonographic appearance of the thyroid gland in clinically normal horses to establish the value of these modalities for assessment of the thyroid gland in this species. Horses were divided into two age groups. One group consisted of eight horses between 3 and 10 years of age and the other of seven horses between 11 and 20 years of age. Total T4 concentrations were within the laboratory reference interval in all horses. Thyroid to salivary (T/S) ratio, percent dose uptake of pertechnetate (Na99mTcO4) and thyroid lobe volume were calculated. The echogenicity...
Bithell S, Habershon-Butcher JL, Bowen IM, Hallowell GD.The aims of this study were to assess the repeatability and reproducibility of transabdominal ultrasonography to assess intestinal wall thickness in adult Thoroughbred horses (n = 8). Ultrasonographic cineloops were captured by one examiner from each horse for five consecutive days. During each examination at least three cineloops were obtained for five different intestinal tract locations. Measurements were performed by three separate observers to assess reproducibility and measured on three separate occasions by three observers to evaluate short-term repeatability. The repeatability of measu...
Dicken M, Munday JS, Archer RM, Mayhew IG, Pandey SK.Equine cutaneous fungal granulomas have been previously referred to in New Zealand (Fairley 1998), and are described in the veterinary literature from around the world, including North America and Australia (Pascoe and Summers 1981; Genovese et al. 2001; Valentine et al. 2006), but no peer-reviewed reports appear published in the literature in New Zealand. Described here is a case of multiple cutaneous fungal granulomas caused by Alternaria spp. in a horse in New Zealand.
Faleiros RR, Nuovo GJ, Flechtner AD, Belknap JK.There is increasing evidence of involvement of inflammatory cells in acute laminitis. Objective: To immunolocalise monocytes/macrophages and B and T lymphocytes in the laminar tissue of normal horses and those with black walnut extract (BWE)-induced laminitis. Methods: Immunohistochemistry was used in archived laminar tissue samples from 20 horses divided equally into 4 groups: control animals (CON), and those administered BWE at 1.5 h (1.5H DTP group), at the onset of leucopenia (3H DTP group) and at the onset of lameness (LAM group). Antibodies against CD3, CD20 and CD163 were used to recogn...
Viñuela-Fernandez I, Jones E, McKendrick IJ, Molony V.To evaluate quantitative sensory testing (QST) of the feet of laminitic horses using a power-assisted hoof tester. Objective: Hoof Compression Thresholds (HCTs) can be measured reliably and are consistently lower in horses with chronic laminitis than in normal horses. Methods: HCTs of chronic laminitic (n=7) and normal horses (n=7) were repeatedly measured using a hydraulically powered and feedback controlled hoof tester. Data from 2 tests, at 3 sites in both forefeet, during 3 sessions were collected and statistically analysed using linear mixed models. Results: The mean±s.e. HCT for the lam...
Witte SH, Witte TH, Harriss F, Kelly G, Pollock P.To determine the association between owner-reported noise and findings during dynamic respiratory endoscopy (DRE) in a large case series. Objective: The sensitivity of owner-reported noise for dynamic upper respiratory tract obstructions in horses is low, and the specificity is high. Methods: One hundred horses underwent DRE for the investigation of abnormal respiratory noise and/or poor performance. The association of abnormal noise with findings during DRE was evaluated. Results: Eighty-five horses underwent DRE for the investigation of abnormal respiratory noise. Of these, 82% were found to...
Davidson EJ, Martin BB, Boston RC, Parente EJ.Although well documented in racehorses, there is paucity in the literature regarding the prevalence of dynamic upper airway abnormalities in nonracing performance horses. Objective: To describe upper airway function of nonracing performance horses with abnormal respiratory noise and/or poor performance via exercising upper airway videoendoscopy. Methods: Medical records of nonracing performance horses admitted for exercising evaluation with a chief complaint of abnormal respiratory noise and/or poor performance were reviewed. All horses had video recordings of resting and exercising upper airw...
Hart SK, Sullins KE.Results of surgical treatment of sinonasal disease in horses have been reported previously; however, this paper describes the outcome of horses in which a specific post operative treatment protocol was used. Objective: The objectives of the study were to determine: 1) short- and long-term outcome; 2) complications; and 3) recurrence rates of different disease processes, when horses were treated with a specific treatment protocol. Methods: Medical records of horses presented for surgical treatment of sinonasal disease from 1996-2007 were reviewed. Results and duration of surgical exploration we...
Monclin SJ, Farnir F, Grauwels M.Tetracaine hydrochloride (THCl) has been reported to cause irritation in dogs. In man, some topical anaesthetics have been shown to disrupt the tear film. Tear break-up time (TBUT) is a useful test allowing an assessment of the quality of the precorneal tear film. Only one TBUT value has been reported in horses with no information on the technique used. Objective: To provide a method for performing the TBUT in horses and to report any side effects of a single application of THCl in clinically normal horses, particularly on the stability of the tear film. Methods: In Study 1, one drop of 0.5 or...
Barakzai SZ, Dixon PM.To correlate resting and exercising endoscopic grades of laryngeal function in horses undergoing high-speed treadmill endoscopy (HSTE) using the Havemeyer grading system. To correlate dorsal displacement of the soft palate (DDSP) seen at rest with palatal function during exercise. Methods: Records of horses that underwent HSTE examination (1999-2009) were reviewed. Resting laryngeal function score and other abnormalities noted on resting endoscopy were recorded as were results of HSTE. Results of resting and exercising endoscopic findings were correlated. Results: 281 horses underwent HSTE. Th...
Leise BS, Faleiros RR, Watts M, Johnson PJ, Black SJ, Belknap JK.There is a need to assess the laminar inflammatory response in a laminitis model that more closely resembles clinical cases of sepsis-related laminitis than the black walnut extract (BWE) model. Objective: To determine if a similar pattern of laminar inflammation, characterised by proinflammatory cytokine expression, occurs in the CHO model of laminitis as has been previously reported for the BWE model. Methods: Sixteen horses administered 17.6 g of starch (85% corn starch/15% wood flour)/kg bwt via nasogastric (NG) tube were anaesthetised either after developing a temperature>38.9°C (DEV ...
Furr M, Howe D, Reed S, Yeargan M.Diagnosis of equine protozoal myeloencephalitis (EPM) remains a challenge for equine practitioners. Current utilized methods have inadequate sensitivity and specificity, because of a high number of false positive results. Objective: Evaluation of antibody indices to Sarcocystis neurona should provide high sensitivity and specificity for diagnosis of EPM. Methods: Archived samples from 29 clinical patients. Methods: Archived serum and cerebrospinal fluid (CSF) samples from clinical patients with either EPM (14) or cervical vertebral compressive myelopathy (CVM) (15) were examined and tested for...
Todhunter RJ, Erb HN, Roth L.The historical, clinical, laboratory, surgical and necropsy findings in 54 cases of gastric rupture in horses are described. Eleven per cent of the deaths of horses undergoing exploratory coeliotomy for colic during the period of the study were a result of gastric rupture. Comparison with all horses which had exploratory coeliotomies for colic over an eight year period did not show that horses with gastric rupture were different from these reference horses regarding age, breed or season. There were fewer stallions than expected in the gastric rupture group. Horses with histories of both acute ...
Bourret V, Croville G, Mansuy JM, Mengelle C, Mariette J, Klopp C, Genthon C, Izopet J, Guérin JL.Recent in-depth genetic analyses of influenza A virus samples have revealed patterns of intra-host viral genetic variability in a variety of relevant systems. These have included laboratory infected poultry, horses, pigs, chicken eggs and swine respiratory cells, as well as naturally infected poultry and horses. In humans, next generation sequencing techniques have enabled the study of genetic variability at specific positions of the viral genome. The present study investigated how 454 pyrosequencing could help unravel intra-host genetic diversity patterns on the full-length viral hæmagglutin...
Fielding CL, Magdesian KG, Carlson GP, Ruby RE, Rhodes DM.Multi-frequency bioelectrical impedance analysis (MF-BIA) has been used to evaluate extracellular fluid volume (ECFV), but not fluid fluxes associated with fluid or furosemide administration in horses. If able to detect acute changes in ECFV, MF-BIA would be useful in monitoring fluid therapy in horses. Objective: The purpose of this study was to evaluate the ability of MF-BIA to detect acute fluid compartment changes in horses. We hypothesized that MF-BIA would detect clinically relevant (10-20%) changes in ECFV. Methods: Six healthy mares were used in the study. Methods: This is an original ...
Barclay WP, Foerner JJ, Phillips TN.Volvulus of the large colon was diagnosed at surgery in 25 horses during a 4-year period. Two horses had a recurrence of the condition after successful correction. Mucosal necrosis was found to be a grave prognostic sign, as it was a consistent finding in horses that died at the time of surgery. Long-term colon dysfunction was not clinically evident in surviving horses.
Johnson PJ, Ganjam VK, Slight SH, Kreeger JM, Messer NT.The role of glucocorticoids (GCs) in the pathogenesis of laminitis is incompletely understood. Local tissue activity of GC is regulated by the steroid converting enzyme, 11beta-hydroxysteroid dehydrogenase-1 (11beta-HSD-1). Changes in integumentary (skin and hoof lamellar) 11beta-HSD activity occurring during laminitis could affect the extent to which GCs are involved in its development. Objective: That changes in integumentary 11beta-HSD-1 activity associated with the laminitic condition would lead to elevated local tissue levels of GCs, which could subsequently contribute, through paracrine ...
Cheetham J, Radcliffe CR, Ducharme NG, Sanders I, Mu L, Hermanson JW.Studies are required to define more accurately and completely the neuroanatomy of the equine dorsal cricoarytenoid muscle as a prerequisite for developing a neuroprosthesis for recurrent laryngeal neuropathy. Objective: To describe the anatomy, innervation, fibre types and function of the equine dorsal cricoarytenoid muscle. Methods: Thirty-one larynges were collected at necropsy from horses with no history of upper airway disease and 25 subjected to gross dissection. Thereafter, the following preparations were made on a subset of larynges: histochemical staining (n = 5), Sihler's and acetylch...
Jackson C, de Lahunta A, Divers T, Ainsworth D.We evaluated creatine kinase (CK) activity in the cerebrospinal fluid (CSF) of 128 horses with various neurological disorders. No association was found between CSF CK activity and CSF red blood cell count, CSF nucleated cell count, CSF total protein concentration, or serum CK activity. The sensitivity and specificity of CSF CK activity as a diagnostic test for protozoal myelitis in horses (61% and 56%, respectively) was higher than for cervical stenotic myelopathy, degenerative myelopathy, or motor neuron disease, but was considered to be inadequate to be of use diagnostically. Contamination o...
Skrzypczak H, Reed R, Barletta M, Quandt J, Sakai D.To describe the incidence of postanesthetic signs of colic (PASC) in horses and determine if perianesthetic administration of hydromorphone was associated with an increased risk of PASC. Methods: Retrospective, cohort study. Methods: A total of 409 horses. Methods: Anesthesia and clinical records of horses admitted for various procedures from July 2018 to September 2019 were reviewed. Signs of colic and interventions were recorded up to 48 hours after anesthesia. A binomial logistic regression model was used to evaluate the association between the type of surgery, administration of hydromorpho...
Schneider RK, Bramlage LR, Gabel AA, Barone LM, Kantrowitz BM.The medical records and radiographs of all horses with a third carpal bone fracture admitted to The Ohio State University Veterinary Hospital from 1979 to 1987 were reviewed. Three hundred and seventy-one fractures were found in 313 horses; 57 percent were Standardbreds, 41 per cent were Thoroughbreds, and only 1.6 per cent were Quarterhorses. All were young racehorses (average age = 3.1 years). Third carpal fractures occurred more frequently in the right limb (60 percent) than the left limb (40 percent); Thoroughbreds had a greater right-left disparity (67.5 percent R, 27.1 per cent L). Fract...
Trumble TN.The first month of life is a vulnerable time for foals. They must adjust to their environment while they are still compromised immunologically, and their musculoskeletal system is rapidly growing and adjusting to stresses from an increasing amount of exercise. Therefore, if a foal is born with or acquires an abnormality or disease related to the musculoskeletal system, rapid adjustments must be made to allow the foal to grow and respond so that future athletic performance will not be compromised. Problems must be identified early, which requires thorough examinations. This article summarizes t...
Fischer AT, Lloyd KC, Carlson GP, Madigan JE.Laparoscopy was performed in 5 clinically normal horses. Abdominal fluid protein content and WBC count increased markedly in all horses. Necropsy findings were confined to an increased amount of slightly turbid abdominal fluid. Five examples of applications of laparoscopy in horses with abdominal problems indicated that laparoscopy can be a valuable diagnostic procedure in the horse.
Rezabek GB, Donahue JM, Giles RC, Petrites-Murphy MB, Poonacha KB, Rooney JR, Smith BJ, Swerczek TW, Tramontin RR.Histoplasmosis was diagnosed in nine horses during 1986-1990. The infection with Histoplasma capsulatum caused granulomatous placentitis and abortion in one mare in the 7th month of gestation and three mares in the 10th month. Four newborn foals died from severe granulomatous pneumonia within a few days of birth; and a weanling thoroughbred developed granulomatous pneumonia and lymphadenitis at 5 months of age.
Whitton RC, Kannegieter NJ.The clinical presentation and outcome of treatment is presented for 26 cases of osteochondral fragmentation of the plantar/palmar proximal aspect of the proximal phalanx. Twenty-three were racing Standardbreds and three were racing Thoroughbreds. The most common reason for presentation was an inability to run straight at high speed. Only eight horses presented for lameness, although on examination 19 were lame. A positive flexion test was recorded in 90% of affected fetlock joints and effusion in 48%. Arthroscopic fragment removal was performed on 23 occasions in 21 horses and arthrotomy in on...
Thorsen J, Little PB.A Standardbred mare became paralyzed shortly after showing signs of an upper respiratory infection. The mare was euthanized and equine herpesvirus type 1 was isolated from the brain and spinal cord.
Holman PJ, Hietala SK, Kayashima LR, Olson D, Waghela SD, Wagner GG.A horse with no prior clinical history of equine piroplasmosis tested negative for Babesia caballi and Babesia equi in the complement fixation test before importation into the United States from France. After 5 years in residence in the United States, the animal tested serologically positive for B. equi by the complement fixation test, the immunofluorescent antibody test, and Western blot analysis. The carrier status of the horse was confirmed by culture of B. equi parasites. In vitro culture offers an efficient and comparatively inexpensive method to determine the carrier status of horses sus...
Slocombe JO, McCraw BM.The efficacy of ivermectin against later fourth-stage Strongylus vulgaris larvae was studied in pony foals at 14 and 35 days after treatment. These foals had been reared parasite-free, inoculated with 500 infective larvae and 56 days later given either ivermectin at 200 micrograms/kg or a placebo intramuscularly. At necropsy, foals were examined for lesions and larvae grossly and histologically. Ivermectin was found to be highly effective (98.6%) against later fourth-stage larvae in five foals which were examined at 35 days after treatment, but not in five others examined at 14 days (72.5%). I...
Baldwin GI, Pollitt CC.Venography (retrograde venous angiography) is a relatively simple and practical method for vascular assessment of the digits in the standing horse. The technique is a useful adjunct to routine radiography. The clinical use of the laminitis venogram has resulted in a more comprehensive understanding of the collateral pathology associated with distal phalanx displacement and abnormal hoof growth. The effectiveness of therapeutic procedures such as hoof wall resection, coronary band grooving, deep digital flexor tenotomy, and therapeutic shoeing can be assessed by serial venography. This article ...
Crijns CP, Gielen IM, van Bree HJ, Bergman EH.A 5-year-old Rheinlander gelding was evaluated for left hindlimb stifle lameness. The lameness was localised to the stifle, but source of the lameness was not specifically diagnosed from the physical, radiographic and ultrasonographic examinations. Computed tomography (CT) and CT arthrography were therefore used for further investigation since these imaging techniques image bony structures, cartilage and soft tissues. This examination showed multiple lesions in the stifle: an osteochondrosis dissecans like lesion of the medial femoral condyle, bony fragments, cartilage trauma and caudal crucia...
Kaaden OR, Eichhorn W, Essbauer S.There is continual variation in viral epidemics regarding clinical symptoms, duration and disappearance, and the emergence of new diseases. This can be observed in both human and animal diseases. This evolution of virus diseases is mainly related to three factors: aetiological agent, host and environment. As far as genetic alterations of the virus are concerned, two major mechanisms are involved: mutations such as recombination and reassortment; and selection for resistance or susceptibility. This review focuses on the epidemiology of newly emerged virus diseases in man and animals, such as ac...