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.
Gilger BC, Yang P, Salmon JH, Jaffe GJ, Allen JB.To determine whether a chemokine (RANTES)-like protein expressed by ciliary epithelium plays a role in uveitis. Methods: 3 clinically normal horses intradermal, 5 eyes from 5 horses with recurrent uveitis, and 10 normal eyes from 5 age- and sex-matched horses. Methods: Cross-reactivity and sensitivity of recombinant human (rh)-regulated upon activation, normal T-cell expressed and secreted (RANTES) protein were evaluated in horses by use of intradermal hypersensitivity reactions and a chemotaxis assay. Aqueous humor and ciliary body of eyes from clinically normal horses and horses with uveitis...
McKenzie EC, Valberg SJ, Godden SM, Pagan JD, Carlson GP, MacLeay JM, DeLaCorte FD.To determine whether plasma, urine, and fecal electrolyte and mineral concentrations differ between clinically normal horses and Thoroughbreds with recurrent exertional rhabdomyolysis (RER) after consumption of diets varying in cation-anion balance. Methods: 5 Thoroughbred mares with RER and 6 clinically normal mixed-breed mares. Methods: Each of 3 isocaloric diets designated as low, medium, and high on the basis of dietary cation-anion balance (DCAB) values of 85, 190, and 380, respectively, were fed to horses for 14 days. During the last 72 hours, 3 horses with RER and 3 control horses had d...
Matiasovic J, Lukeszová L, Horín P.Primers based on GenBank sequences within the 5' untranslated region (UTR) of the human and horse tumour necrosis factor alpha (TNF-alpha) genes were designed and used to amplify a 522-bp product. Sequencing of five clones derived from five independent PCRs obtained from three different animals of three different breeds (Old Kladruber, Akhal-Teke and Shetland Pony) revealed a high level of sequence identity to the TNF-alpha promoter regions of other species. The existing GenBank horse sequences were confirmed and extended upstream by 230 nucleotides. Based on the sequence obtained, a new horse...
Frank N, Sojka JE, Latour MA.To measure and compare the concentration and composition of very low-density lipoprotein (VLDL) in plasma and selected lipids in serum of horses fed mixed grass hay ad libitum or denied feed for 36 hours. Methods: 4 healthy adult mares. Methods: Mares were either fed mixed grass hay ad libitum or denied feed for 36 hours beginning at 8:00 AM. Blood samples were collected every 2 hours during the study period and analyzed for nonesterified fatty acid (NEFA), triglyceride (TG), VLDL, and glucose concentrations and composition of VLDL. Results: Withholding feed significantly increased mean serum ...
Merritt AM, Xie H, Lester GD, Burrow JA, Lorenzo-Figueras M, Mahfoud Z.To evaluate the reliability of a method for inducing colic via small intestinal distention in horses and to examine the analgesic potential of bilateral electroacupuncture (EAP) at the Guan-yuan-shu (similar to BL21) acupoint. Methods: 5 healthy adult horses, each with a gastric cannula. Methods: A polyester balloon connected to an electronic barostat was introduced into the duodenum via the gastric cannula. At 2 specified intervals (before and after commencement of EAP), the balloon was inflated to a barostat-controlled pressure that induced signs of moderate colic. Each inflation was maintai...
Adam EN, Morley PS, Chmielewski KE, Carman J, Gonzales G.Because of the contagious nature of influenza virus it is necessary to identify infected individuals after the virus is introduced into a population. The aim of this study was to characterise influenza virus detection with commercially available assays after intranasal vaccinating horses with cold-adapted influenza virus. Seven horses were vaccinated and placed with 3 unvaccinated horses. Nasal secretion samples were evaluated using 2 antigen detection assays. All 10 horses were positive in the Flu OIA assay during the study period, but only one horse was positive on one sample using the Direc...
Pirie RS, Dixon PM, McGorum BC.To investigate the relative importance of inhaled particulates and soluble components in the response to inhaled hay dust suspension (HDS), heaves (previously termed chronic obstructive pulmonary disease; n = 7) and control (n = 6) horses were given inhalation challenges with whole and fractionated HDS. Fractionation was achieved by centrifugation to yield supernatant (SUP) and particulate debris. The particulates were then washed repeatedly in saline to produce a washed particulate (WP) fraction which comprised mainly fungal spores, and a wash fraction (WF) which comprised saline and soluble ...
Pirie RS, Collie DD, Dixon PM, McGorum BC.To evaluate inhaled hay dust suspensions (HDS) as a tool for the diagnosis and investigation of heaves, the pulmonary inflammatory and functional consequences of inhalation challenge with 3 different HDS were determined in 6 control and 7 asymptomatic heaves horses. Heaves horses given HDS challenge developed the characteristic features of heaves, including airway neutrophilia, obstructive airway dysfunction and mucus hypersecretion. While HDS challenge induced a mild airway neutrophilia in controls, the no-response threshold for controls was greater than that of heaves horses, and there was n...
Kolm-Stark G, Wagner R.Icelandic horses in Austria are commonly affected by an allergic inflammatory skin disease recurring during the summer seasons, which shares characteristic features with Culicoides hypersensitivity. However, the causative agents have not yet been identified. Therefore, intradermal skin testing (IDST) with a standardised extract of Culicoides variipennis and 21 other allergens relevant within Austria was performed in 81 Icelandic horses. All horses included into the study were treated regularly with ivermectin and had no history of administration of anti-inflammatory drugs. Forty-three of these...
Pirie RS, McLachlan G, McGorum BC.Currently, heaves is investigated by exposing susceptible horses to dusty hay. Consequently, the response will be dependent on the organic dust content and composition of the hay. It was hypothesised that the use of a hay dust suspension (HDS) would reduce the variability of the challenge and therefore standardise experimental protocols. Furthermore, analysis of HDS would also permit further investigation of the organic dust components responsible for the response. Three hay dust suspensions (HDS-1, 2 and 3) were prepared for use in the diagnosis and investigation of heaves. HDS were produced ...
Beadle RE, Horohov DW, Gaunt SD.We hypothesised that horses affected with summer pasture-associated obstructive pulmonary disease (SPAOPD) react to an allergen or allergens in their summer environment that is either absent or present at lower levels in their winter environment; and that such allergens stimulate SPAOPD-affected horses to produce a different T helper lymphocyte cytokine profile from that of control horses. The primary objective of this study was to determine the cytokine mRNA profile of T helper lymphocytes obtained from summer pasture-associated obstructive pulmonary disease (SPAOPD) affected horses when 1) t...
Pickles K, Pirie RS, Rhind S, Dixon PM, McGorum BC.The aim of this study was to develop a diagnostically useful smear method for preparation of equine bronchoalveolar lavage fluid (BALF) for use by practitioners. A smear method for equine BALF preparation which included the addition of serum was developed, and cell morphology, differential cell counts (DCC) and repeatability of counting DCC compared with those of cytocentrifuged BALF preparations. BALF samples (n = 21) were collected from 5 control horses and 5 heaves-susceptible horses. Smear preparations of BALF produced smaller, darker, staining cells, making cytological identification more...
Pickles K, Pirie RS, Rhind S, Dixon PM, McGorum BC.Bronchoalveolar lavage fluid (BALF) samples are often subject to time delays, possibly with temperature fluctuations, between collection and processing. The aim of this study was to evaluate the effects of time, temperature and 2 different fixatives on equine BALF cytology, in order to develop guidelines for optimal equine BALF storage conditions. Total nucleated cell count (TCC), differential cell counts (DCC), absolute cell counts (ACC), cell viability, cell morphology and bacterial growth of BALF samples stored at 4, 18 (+/- addition of formalin- or alcohol-based fixatives) and 38 degrees C...
Wilmink JM, van Herten J, van Weeren PR, Barneveld A.In accidental wounds, trauma and infection can result in dehiscence of primarily closed wounds and in sequestrum formation when cortical bone is exposed. In experimental studies, it has been shown that second intention healing is faster and occurs with less complications in ponies than in horses. Also, a greater initial inflammatory response was seen in ponies. Based on these experimental data, it was hypothesised that accidental wounds in ponies would heal with a lower incidence of wound dehiscence and/or sequestrum formation compared to horses. A retrospective study of 89 ponies and 422 hors...
Dyson SJ.The purposes of this study were to investigate the ultrasonographic appearance of the patellar ligaments in clinically normal horses and to describe the clincical features, diagnosis and outcome of patellar ligament injury. The medial, middle and lateral patellar ligaments of 5 Thoroughbred and 5 Warmblood horses, free from lameness and in full work, were examined ultrasonographically. The ligaments were all of uniform echogenicity and each ligament was fairly consistent in its shape. The size of the ligaments of the Warmblood horses tended to be bigger than the lighter bodyweight Thoroughbred...
van den Boom R, Rijkenhuizen AB.Septic inflammation of the synovial fossa in the horse is a severe disorder that can lead to permanent invalidity. The synovitis can occur as a result of a perforating trauma, or via the blood (haematogenous). The latter route is rare in the adult horse. Three cases of suspected haematogenous septic synovitis are described in adult horses (older than 1 year). In two horses, timely and adequate treatment resulted in recovery, but this was followed by fatal recurrence. In one of these horses a persistent primary infection was found as cause; the other horse was not available for autopsy. The thi...
Franz S, Baumgartner W.Oesophageal endoscopy in cattle has been rarely reported in the literature. It has, however, been used for many years as an aid to the diagnosis and treatment of illnesses of the upper gastrointestinal tract in small animals and horses. We have assessed the potential value of oesophagoscopy on 120 bovine patients presented at the 2nd Medical Clinic for Ruminants and Swine at the University of Veterinary Medicine, Vienna, over a period of three years. In the course of the study, cattle exhibiting symptoms such as salivation, regurgitation or swelling in the neck region were referred for endosco...
Herholz C, Straub R, Gerber V, Wampfler B, Lüthi S, Imhof A, Moens Y, Busato A.The pulmonary health of 66 horses was assessed by a clinical examination and simple supplementary diagnostic methods. Single breath diagrams for CO(2) (SBD-CO(2)) and derived lung function indices were used to determine pulmonary function. The clinical signs in different groups were related to the results of the lung function indices derived from the SBD-CO(2). In horses with moderate to severe chronic obstructive pulmonary disease (COPD), a significant relationship was found between the respiratory frequency and the ratio of Bohr's dead space to the tidal volume (VD(Bohr)/VT), and between the...
Doyle-Jones PS, Sullins KE, Saunders GK.To compare synovial regeneration in the equine carpus after mechanical or CO(2) laser synovectomy. Methods: Arthroscopic partial synovectomy was performed in the radiocarpal and intercarpal joints. Methods: Twelve horses, 3 to 6 years of age, were randomly divided into 3 groups. Methods: The antebrachiocarpal and intercarpal joints in each horse were randomly assigned a treatment such that each horse had one joint treated as a control (arthroscopic lavage), one in which a mechanical or CO(2) laser partial dorsal carpal synovectomy was performed, and one in which a combination of the mechanical...
Moore BD, Balasuriya UB, Hedges JF, MacLachlan NJ.Equine viral arteritis (EVA) is an endotheliotropic viral disease of horses caused by equine arteritis virus (EAV). Although there is only one serotype of EAV, there is marked variation in the virulence of different strains of the virus. The replication and cytopathogenicity of three well-characterized strains of EAV of different virulence to horses were compared in rabbit kidney (RK-13) and primary equine pulmonary artery endothelial cells (ECs). Viral protein expression, plaque size, and cytopathogenicity of all three viruses were similar in RK-13 cells, whereas two virulent strains of EAV w...
Grulke S, Gangl M, Deby-Dupont G, Caudron I, Deby C, Serteyn D.Gastrointestinal disorders in horses leading to endotoxic shock could have further consequences on other splanchnic organs such as the pancreas, as can be seen in humans suffering from septic shock. In this study, the range of enzymatically active trypsin (EAT) in healthy horses was established and is similar to the range observed in healthy humans. EAT values were determined in horses with acute abdominal crises on admission as well as during anaesthesia and in the postoperative phase. A significant increase in plasma EAT was found in 59% of the horses with surgical colic when compared to our...
Mizukoshi F, Maeda K, Hamano M, Iwata H, Matsumura T, Kondo T, Sugiura T.In this study, IgG subclass responses against equine herpesvirus type 4 (EHV-4) were examined by enzyme-linked immunosorbent assay (ELISA) using a type-specific region of EHV-4 glycoprotein G (gG). ELISA using sera collected from horses experimentally infected with EHV-4 revealed that IgGa and IgGb antibodies were detected at high level, but IgGc and IgG(T) antibody responses were detected at low level or were undetectable. The IgGa antibody response reached its peak on day 10 post-infection, and then dropped. The IgGb antibody response reached its maximum level on day 12 post-infection, and t...
Erichsen C, Berger M, Eksell P.The aim of this study was to describe the scintigraphic appearance and location of the sacroiliac joint (SI-joint) in dorsal and dorso 30 degree lateral views of the equine pelvis in a scintigram. The pelvis from 10 different horses was prepared by attaching plastic tubes along relevant margins of the bone and around the SI-joint. A radioactive solution was injected into the tubes, and scintigraphic images were acquired with a gamma camera. Five specific landmarks were identified on the left and right sides of the pelvis. There was no significant difference in the distance measurements between...
Keegan KG, Yonezawa Y, Pai PF, Wilson DA.Video-based kinematic analysis of gait in horses is accurate for quantification of lameness and reliable for identification of the affected limb. Algorithms for the measurement of the vertical head and pelvic displacement and phase correlation with vertical displacement of one forelimb and hindlimb foot have been developed for this purpose. However, because of camera field-of-view limitations, video-based analysis of gait can only be reliably accomplished with the horse constrained to move on a treadmill. This paper describes the use of 2 single-axis accelerometers and 2 gyroscopic transducers...
Palacios H, Hibarren I, Olalla MJ, Cala V.The diagnosis of lead poisoning in horses living on farmland in the vicinity of a battery recycling plant was based on clinical signs as well as on laboratory findings. Chemical analysis of six surface soils (0-15 cm) and herbage samples taken at different distances to the recycling plant showed very high total lead levels in the closest sites to the facility and a clear decrease with distance. Total lead levels in soil samples ranged from 127 to 5657 mg kg(-1), with more than 70% of lead extractable by EDTA in the most polluted soils. Lead levels in the aerial part of herbage samples were in ...
Tee SY, Horadagoda N, Mogg TD.Flaviviruses, including Kunjin virus, are arboviruses that cause encephalomyelitis in humans and horses. This case report describes an Arabian gelding exhibiting neurological signs of flavivirus encephalomyelitis, the diagnostic investigation and confirmation of an unreported case of Kunjin virus equine encephalomyelitis in Australia.
Ostevik L, de Souza GA, Wien TN, Gunnes G, Sørby R.Two horses with chronic uveitis and histological lesions consistent with equine recurrent uveitis (ERU) were examined. Microscopical findings in the ciliary body included deposits of amyloid lining the non-pigmented epithelium, intracytoplasmic, rod-shaped, eosinophilic inclusions and intraepithelial infiltration of T lymphocytes. Ultrastructural examination of the ciliary body of one horse confirmed the presence of abundant extracellular deposits of non-branching fibrils (9-11 nm in diameter) consistent with amyloid. Immunohistochemistry revealed strong positive labelling for AA amyloid and m...
Paraschou G, Vogel PE, Lee AM, Trawford RF, Priestnall SL.Multisystemic eosinophilic epitheliotropic disease (MEED) is a rare condition of equids characterized by eosinophilic infiltration of multiple organs. Clinical signs are variable depending on the affected organs. The most common clinical signs include chronic weight loss, diarrhoea and exfoliative dermatitis. Respiratory distress and raised liver enzymes are less frequently seen. The cause is unknown and the pathogenesis is poorly understood. There are less than 50 reported cases of horses with MEED. We now document the lesions in three donkeys with fluctuating or chronic loss of weight, letha...
Greet TR.Radiological features of the oesophagus of 7 normal horses and 13 with oesophageal lesions are described. The use of barium sulphate as a contrast agent and the techniqes of its administration are discussed. It is suggested that chronic intermittent oesophageal impaction with food material was a predisposing factor in the development of a localised oesophageal dilation in 3 horses and that one other probably resulted from an injury. A similar dilatation was seen which resulted from oesophageal constriction by a vascular ring. Megaoesophagus was seen in 2 ponies associated with grass sickness a...
McClure JR, Chapman MR, Klei TR.Since 1978, 20 surgical implantations of either Strongylus vulgaris or Strongylus edentatus have been performed in our laboratory for the purpose of obtaining single species cultures of these parasites. Following surgical implantation peak EPG values of 13-327 (S. vulgaris) and 363-1284 (S. edentatus) generally occurred during the first 3 weeks post-implantation. Duration of infections was as long as 5 years. Successful outcome of such surgeries appears to be related to the total number of parasites used (> or = 38) and the ratio of female to male worms implanted (1:1 or 2:1).
Blaga R, Cretu CM, Gherman C, Draghici A, Pozio E, Noeckler K, Kapel CM, Dida I, Cozma V, Boireau P.Herbivorous animals are usually, by virtue of their diet, outside the major transmission cycles of Trichinella spp. However, since 1975, the year of the first report of human trichinellosis caused by the consumption of infected horse meat, the domestic horse has appeared as a novel vector of Trichinella spp. infection to humans, with 15 outbreaks documented in France and Italy. Romania, one of the main countries exporting horses into the European Union (EU), experienced a dramatic increase of Trichinella spp. infection in both domestic pigs and humans in the 1990s. Some Trichinella spiralis-in...
Oleksiewicz MB, Snijder EJ, Normann P.A putative zinc finger (ZF) domain in the Equine arteritis virus (EAV) nsp1 protein was described recently to be required for viral transcription. The nsp1 ZF (50 aa) was expressed on the surface of M13KE gIII phage, fused to the N terminus of the phage pIII protein. To evaluate the functionality of the ZF domain, a binding assay was developed, based on the use of immobilized Ni(2+) ions (Ni-NTA). Phages displaying ZF bound significantly better to Ni-NTA than did phages displaying negative-control peptides, which also contained metal-coordinating residues. Also, binding of ZF-displaying phages...
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.
Beech J, Dubielzig R, Bester R.Periodic episodes of diffuse central nervous system disease occurred in a yearling Thoroughbred gelding that had a history of frequent respiratory tract disease and stunted growth. Hepatic encephalopathy was diagnosed on the basis of history, clinical signs, prolonged bromsulphalein clearance, and increased blood ammonia content. Because of the poor prognosis and recurrent clinical signs the horse was euthanatized. Necropsy revealed an arteriovenous anomaly and thrombosis of the portal vein. Histologically, there was diffuse primary astrocytosis of the brain.
Thomsen ME, Davis EG, Rush BR.A 5-y-old Paint horse gelding was evaluated for acute laminitis after exposure to black walnut shavings. The gelding's feet were previously soaked in an ice bath continuously for approximately 24 h. Treatment consisted of anti-inflammatory and vasodilator therapy. Serial radiographs revealed progressive palmar deviation of the third phalanx and subsolar abscesses in both forefeet. The gelding developed purulent discharge from the right coronary band and the hoof wall detached circumfrentially. Euthanasia was elected after 54 days. Continual exposure of the gelding's feet to ice water temperatu...
Wales AD, Whitwell KE.Two samples were taken postmortem from the rectum of each of 14 horses with grass sickness and 10 control horses, and four sections stained with haematoxylin and eosin were examined. By using as a criterion of grass sickness the presence of three chromatolytic neurons, 10 of the 14 cases were positive and none of the control horses was positive, giving a sensitivity of 71 per cent and a specificity of 100 per cent. No other histological features appeared to be of diagnostic value, and staining for Nissl substance in neurons with cresyl fast violet and methyl green-pyronin did not improve the s...
Verwilghen D, van Galen G, Busoni V, Cassart D, Salciccia A, Serteyn D, Grulke S.Persistent Meckel's diverticulum is an uncommon embryonic developmental anomaly of the distal small intestine created by a portion of the vitelline duct adjacent to intestine that remains patent. This portion can form a diverticulum (Meckel's diverticulum) or a fibrous band, called vitelloumbilical band, and can be associated with colic after local impaction or strangulation of the small intestine around the remnant. This report describes two cases of Meckel's diverticulum with different morphological features in older horses. This congenital disorder should be considered as a reason for abdom...
Sanders SG, Tucker RL, Bagley RS, Gavin PR.Magnetic resonance imaging (MR) was used to make a diagnosis of equine nigropallidal encephalomalacia in a horse. Equine nigropallidal encephalomalacia is a neurodegenerative disease that has many characteristics with Parkinson-like diseases in humans. Historically, horses were euthanized based on clinical signs and exposure to the toxic weed, yellow star thistle (Centaurea solstitialis). Previously, the disease has only been confirmed on necropsy. MR imaging can provide accurate and sensitive visualization of typical lesions seen in the brain of horses affected with equine nigropallidal encep...
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 ...
Bertone JJ, Dill SG.An ingested metallic foreign body migrated from the stomach and induced restrictive pericarditis in a horse. Necropsy revealed chronic abdominal and acute thoracic lesions. Although rare, ingested foreign body migration should be considered in the differential diagnosis of body cavity disease in horses.
Parente EJ, Richardson DW, Spencer P.Medical records of 57 horses admitted between 1980 and 1991 because of basal sesamoidean fractures were evaluated. Radiographic measurements of fragment size and fracture characteristics were recorded to determine their relationship to outcome. A successful outcome was assessed on the basis of the ability to return to racing, ability to race more than one time, and ability to finish first, second, or third. Any change in racing class also was assessed. There was a significant (P < 0.001) overrepresentation of Thoroughbreds, compared with other breeds in the hospital population. Fractures of...
Sweeney RW, Sweeney CR.Horner's syndrome developed in 2 horses after routine jugular venipuncture. Signs included unilateral sweating of the face in both horses and ptosis in 1 horse. The signs resolved within 14 hours. Signs of a perivascular injection did not develop in either horse. Although Horner's syndrome has been reported after perivascular jugular injections these cases illustrate that the syndrome may develop following routine intravenous injections.
Diallo I, Read AJ, Kirkland PD.A real-time reverse transcription polymerase chain reaction (qRT-PCR) test for the matrix gene of type A influenza viruses was used during the 2007 Australian equine influenza (EI) outbreak in order to confirm diagnosis and, later, eradication of the virus. During the EI outbreak, horses being exported required vaccination and individual proof of freedom from EI. At the end of the outbreak, positive results were obtained from four horses destined for export, because of contamination of the samples with the vaccine. This report highlights the need for EI testing and vaccination to occur on sepa...
Lavoie JP, Carlson GP, George L.Hypertrophic osteopathy was diagnosed in 3 horses and in a pony, ranging in age from 8 to 21 years. There were 2 females, 1 sexually intact male, and 1 gelding. In 3 animals, hypertrophic osteopathy was associated with pulmonary abscesses, bronchogenic squamous cell carcinoma, and ovarian granulosa-cell tumor, respectively, and resulted in death or euthanasia. Duration of the condition ranged from 1 to 4 months. In 1 horse, hypertrophic osteopathy was believed to be secondary to pregnancy, and resolved following uncomplicated delivery of a live foal.