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.
Kempson SA, Davidson ME, Dacre IT.Two hand rasps (tungsten chip blade, solid carbide blade) and an electrically-driven solid carbide axial bur were used to treat the cheek teeth of 2 horses immediately postmortem. All teeth were normal and were rasped to a standard considered satisfactory in practice. Six teeth from each horse served as untreated controls. Following treatment, the teeth were extracted and the clinical crown removed and prepared for scanning electron microscopy. Teeth were also extracted and examined from a horse that had excessive dental treatment previously. Dental debris created by the procedures was collect...
Zerbe H, Schuberth HJ, Engelke F, Frank J, Klug E, Leibold W.In order to investigate pathogenic mechanisms of acute endometritis in cows and mares, we established an in vivo model in both species. Based on the results of an in vitro transmigration system, human recombinant interleukin-8 (rhIL-8; 1.25 microg per mare and 5 microg per cow in 50 ml phosphate-buffered saline) was used to attract polymorphonuclear neutrophil granulocytes (PMNs) into the uteri. Peak numbers of uterine neutrophils were attracted after 6h, in both cows and mares. On average, mares responded more sensitively than cows, with 15 times higher numbers of rhIL-8-attracted uterine neu...
Wilkins PA.Lower airway problems of the adult horse are commonly encountered by the practitioner. Particularly susceptible populations include horses transported for any significant distance and young horses grouped together for training and/or competition. This article presents some of the commonly encountered problems of this patient population, including bacterial pneumonia/pleuropneumonia and influenza, and some uncommon ones, including pulmonary edema, pneumothorax/hemothorax, and acuterespiratory distress syndrome. Information is presented that should allow the practitioner to diagnose these proble...
Barr BS.Lower respiratory tract infection is common in weanling- and suckling-aged animals. Increased susceptibility to disease in this age group can result from a delay in the establishment of a competent immune system and environmental factors, such as overcrowding, shipping, and sales. S zooepidemicus and R equi are the two most common bacterial isolates. S equi is primarily a disease of the lymph nodes and upper respiratory tract. Viral agents can compromise the natural defense mechanisms of the respiratory tract, resulting in secondary bacterial infections. The acute respiratory distress syndrome...
Birks EK, Durando MM, McBride S.EIPH is a condition affecting virtually all horses during intense exercise worldwide. The hemorrhage originates from the pulmonary vasculature and is distributed predominantly bilaterally in the dorsocaudal lung lobes. As the condition progresses, the lung abnormalities extend cranially along the dorsal portions of the lung. An inflammatory response occurs in association with the hemorrhage and may contribute to the chronic sequela. Although conflicting opinions exist as to its affect on performance, it is a syndrome that is thought to increase in severity with age. The most commonly performed...
Roy MF, Lavoie JP.Respiratory disorders are among the most common problems leading horse owners to seek veterinary attention. Accurate diagnosis of these conditions allows for proper treatment to be instituted, much to the benefit of the patient and satisfaction of the client. As an introduction to this issue on equine respiratory disorders, we review some of the tools that are available to equine veterinarians for the diagnosis of respiratory disorders. Physical and endoscopic examination, radiology, diagnostic ultrasound, techniques for sampling the respiratory tract, hematology, blood gas analysis, respirato...
Wilkins PA.The newborn foal can experience problems of the lower respiratory tract that are unique to the neonate. The transition to extrauterine life usually occurs rapidly and in a coordinated manner, but problems associated with the peripartum period, including placentitis, dystocia, infection, and trauma, can result in conditions that compromise gas exchange in the newborn foal. This article reviews the normal transition and presents some of the problems seen in these small patients.
Davidson EJ, Martin BB.Wastage of performance horses because of respiratory dysfunction is common. Appropriate identification of the disease is paramount for treatment recommendations. Diagnostic modalities for upper respiratory tract dysfunction include a thorough physical examination, radiographic evaluation when appropriate, and upper respiratory tract endoscopy. Anatomical deviations or structural are easily identified during resting evaluation, while exercise testing is often necessary to assess thedynamic properties of the upper airway. Utilizing the many diagnostic tools available allows the clinician to make...
Hardy J, Léveilé R.Guttural pouches are unique anatomic structures in Equidae. Conditions affecting the guttural pouches present with clinical signs that are not observed in other domestic species, and treatment of some of these conditions can be challenging. This article describes the anatomy and examination of the guttural pouches and reviews the presenting signs and treatment of the more common conditions affecting them, including empyema, tympany, mycosis, and stylohyoid arthropathy.
Sullivan EK, Parente EJ.Pharyngeal disorders are complex and difficult to treat. Disorders that lead to anatomic derangement, such as trauma and neoplasia, can significantly affect the function of this organ. Pharyngeal dysfunction can manifest as dysphagia, persistent palatal displacement, or exercise intolerance. Secondary complications are serious and life threatening and include aspiration pneumonia, weight loss, and death. Pharyngeal disorders that are only recognizable during strenuous exercise are difficult to diagnose and are treated with limited success, even though they are responsible for significant econo...
Wieringa R, de Vries AA, Rottier PJ.Equine arteritis virus (EAV) is an enveloped, positive-stranded RNA virus belonging to the family Arteriviridae of the order NIDOVIRALES: Six transmembrane proteins have been identified in EAV particles: the nonglycosylated membrane protein M and the glycoprotein GP(5) (previously named G(L)), which occur as disulfide-bonded heterodimers and are the major viral envelope proteins; the unglycosylated small envelope protein E; and the minor glycoproteins GP(2b) (formerly designated G(S)), GP(3), and GP(4). Analysis of the appearance of the GP(2b), GP(3), and GP(4) proteins in viral particles by g...
Schuurman SO, Kersten W, Weijs WA.Horses spend much of their life standing, and they are believed to be able to keep their limbs straight without muscular effort. We tested the hypothesis that the stifle (knee) and hock (tarsal) joints could be stabilized merely with the help of a passive lock mechanism whereby the patella is secured behind a hook, formed by the medial femoral trochlea. In anaesthetized animals and isolated limbs the stifle and hock flex readily under compression. In isolated limbs this collapse was prevented by a small force applied to the patella, mimicking the action of the vastus medialis muscle. In vivo, ...
Hooper-McGrevy KE, Wilkie BN, Prescott JF.Rhodococcus equi causes severe pyogranulomatous pneumonia in foals and in immunocompromised humans. Replication of virulent isolates within macrophages correlates with the presence of a large plasmid which encodes a family of seven virulence-associated proteins (VapA and VapC to VapH), whose functions are unknown. Although cell-mediated immunity is thought to be crucial in eliminating R. equi infection, antibody partially protects foals. The antibody response to both VapA and VapC was similar in six adult horses and six naturally exposed but healthy foals, as well as in eight foals with R. equ...
Von Loewenich FD, Stumpf G, Baumgarten BU, Röllinghoff M, Dumler JS, Bogdan C.Based on seroprevalence studies and tick infection rates, tick-borne human granulocytic ehrlichiosis (HGE) is thought to occur in Germany, but to date no clinical case has been detected. Reported here are the first ehrlichial sequences derived from a German horse that fell ill with granulocytic ehrlichiosis. The analysis of three different genes (16S rRNA gene, groESL, and ankA) revealed up to 100% identity with ehrlichial sequences derived from patients with HGE in other countries or from infected ticks in Germany. Thus, the current lack of clinical cases of HGE in Germany is unlikely to resu...
Szeredi L, Pálfi V, Molnár T.The objective of the investigations was to study the occurrence of the equine herpesvirus type 1 (EHV-1) infection in aborted equine fetuses and in newborn foals and to compare the sensitivity of virus isolation, immunohistochemistry and histology in 101 cases and of fetal serology in 68 cases in the diagnosis of the infection. Out of the 93 aborted equine fetuses and 8 weak foals, 15 (14.9%) (14 fetuses and 1 foal) proved to be EHV-1 infected by immunohistochemical and 13 (12.9%) by virological investigation. Characteristic microscopic changes were seen in several organs in all cases, while i...
Cohen ND, Carey VJ, Donahue JG, Seahorn JL, Harrison LR.Epidemiological and pathological findings of 433 late-term abortions associated with the mare reproductive loss syndrome (MRLS) in central Kentucky were identified by reviewing the records of the University of Kentucky Livestock Diseases Diagnostic Center. The distribution of dates of abortion was clustered during a brief period of time, presumably from a simultaneous environmental exposure. The most common pathological findings were microscopic pulmonary lesions consisting of squamous epithelial cells present in alveoli with or without concurrent infiltration of inflammatory cells (neutrophil...
Larsson P, Persson E, Tydén E, Tjälve H.Horses may be exposed to aflatoxin B(1) (AFB(1)) via inhalation of mouldy dust, leading to high exposure of olfactory and respiratory tissues. In the present study the metabolic activation of AFB(1) was examined in olfactory and respiratory tissues in horse. The results showed covalent binding of AFB(1)-metabolites in sustentacular cells and cells of Bowman's glands in the olfactory mucosa, in some cells of the surface epithelium of nasal respiratory, tracheal, bronchial and bronchiolar mucosa and in some glands in these areas. Immunohistochemistry revealed that cells expressing proteins react...
Wattrang E, Jessett DM, Yates P, Fuxler L, Hannant D.The production of interferon (IFN), interleukin-6 (IL-6), and tumor necrosis factor (TNF) was monitored in horses during the course of influenza A2 virus infections. The effects of two virus strains, Newmarket/2/93 and Sussex/89, were compared, of which the latter is considered the more pathogenic in terms of clinical signs. Ten naive ponies were infected with influenza A/equine/Sussex/89 and 10 with influenza A/equine/Newmarket/2/93, respectively. As expected ponies infected with Sussex/89 showed the most pronounced clinical signs but there was no notable difference in viral excretion compare...
Jones SL, Davis J, Rowlingson K.To determine whether ultrasonography would be useful in the diagnosis of right dorsal colitis in horses. Methods: Retrospective study. Methods: 5 horses with right dorsal colitis and 15 healthy adult horses. Methods: Mural thickness and appearance of the right dorsal colon were determined from ultrasonographic images obtained at right intercostal spaces 10, 11, 12, 13, and 14. Results: The right dorsal colon could be imaged most consistently at the right 11th, 12th, and 13th intercostal spaces, below the margin of the lung and axial to the liver. Mural thickness measured from ultrasonographic ...
de Bruijn CM, Wensing T, van Nieuwstadt RA.The glutaraldehyde coagulation test is a semi-quantitative test used to determine the gammaglobulin concentration in serum. The purpose of this study was to examine the reliability of the different modifications of this test by determining the sensitivity, specificity, positive and negative predictive value, and the prevalence of hypogammaglobulinemia in foals. The results of the glutaraldehyde coagulation test were compared with the serum gammaglobulin concentration as a reference value, determined by measuring total serum protein and the serum protein spectrum. It was concluded that the glut...
Daly K, Shirazi-Beechey SP.Nine oligonucleotide probes complementary to conserved regions of small subunit rRNA from phylogenetically defined clusters of intestinal anaerobic bacteria were designed and evaluated for use in quantitative analysis of intestinal microflora. Optimum wash temperatures (T(w)) were determined according to the temperature of dissociation (T(d)) of each probe and target group specificity was demonstrated by comparing hybridisation to target and non-target rRNA immobilised on nylon membranes. Three probes are targeted to phylogenetic clusters of Clostridiaceae, clusters III, IV and IX, with three ...
Criado-Fornelio A, Martinez-Marcos A, Buling-Saraña A, Barba-Carretero JC.Molecular epizootiology of piroplasmids (Babesia spp., Theileria spp.) and Hepatozoon canis was studied in mammals from southern Europe (mainly from Spain, but also from Portugal and France). Partial amplification and sequencing of the 18s rRNA gene was used for molecular diagnosis. In some particular cases (B. ovis and B. bovis) the complete 18s rRNA gene was sequenced. Blood samples were taken from domestic animals showing clinical symptoms: 10 dogs, 10 horses, 10 cows, 9 sheep and 1 goat. In addition, DNA samples were isolated from blood of 12 healthy dogs and from spleen of 10 wild red fox...
van Maanen C, van Essen GJ, Minke J, Daly JM, Yates PJ.An outbreak of equine influenza H3N8 in a riding school is described retrospectively with emphasis on diagnosis and putative vaccine failure. In March 1995 an outbreak of equine influenza occurred among 11 horses in a riding school, where most horses had received basic primary immunizations and several booster vaccinations against influenza. Six of the 11 diseased horses had received their last booster vaccination within 5 months of the outbreak. Nevertheless, the influenza infection spread rapidly and clinical manifestations were prominent with frequent, harsh, dry coughing often accompanied ...
Illera JC, Silván G, Munro CJ, Lorenzo PL, Illera MJ, Liu IK, Illera M.An amplified enzymeimmunoassay (EIA) was validated for androstenedione in the serum of male horses. We will use the assay as a tool for the diagnosis of equine cryptorchidism. We will compare androstenedione EIA to the currently used methods (testosterone and estrone sulphate determinations). The study was conducted on 115 horses of pure Spanish and Arabian breeds, that included 30 geldings, 60 bilateral cryptorchids and 25 stallions. Androstenedione standard curve covered a range between 0 and 1 ng per well. Low detection limit was 1.54 pg/ml. Intra- and inter-assay coefficients of variation ...
Elce YA, Ross MW, Davidson EJ, Tulleners EP.To describe the surgical technique, complications, and outcome of thyroidectomy in 6 horses. Methods: Retrospective study. Methods: Six horses, 10 to 22 years of age, with unilateral, rapidly enlarging thyroid masses. Methods: Medical records between 1985 and 2000 were reviewed for horses that had unilateral thyroidectomy. Retrieved data included signalment, physical, clinical, and ultrasonographic examination findings, surgical technique, complications, and outcome. A minimum of 6 months follow-up was obtained. Results: Six horses were identified. Three horses had tracheal compression and 2 o...
Gutierrez CV, Riddle WT, Bramlage LR.To determine whether serum thyroxine (T4) concentration was associated with pregnancy rates 15 to 16 days after ovulation in mares and to determine whether thyroid hormone supplementation would enhance fertility in mares. Methods: Cohort study. Methods: 329 clinically normal broodmares. Methods: Mares were examined 15 to 16 days after ovulation to determine whether they were pregnant; blood samples for determination of serum T4 concentration were collected at the same time. Sixty mares were receiving thyroid hormone supplementation prior to the study because of low serum T4 concentration (< 16...
Rodrigues JB, Lilly G.Research and clinical understanding of equine dentistry has progressed in recent years; however, specific knowledge about donkey dentistry is lacking. This article intends to revise unique anatomic features of the head and oral cavity of donkeys, as well as how to correctly examine, diagnose, prevent, and/or treat dental pathology, allowing for a better comprehension of oral and dental disorders affecting these animals throughout their life. It also emphasizes that these disorders need to be taken into account when assessing the welfare of donkeys.
Ramzan PH, Palmer L.Fissures of the occlusal surface of the equine cheek tooth are poorly understood and their association with dental disease is unknown. Objective: To describe the prevalence and location of occlusal fissures in the cheek teeth (CT) of a group of horses referred for dental investigation/treatment, and determine association with intercurrent dental disease. Methods: Digital video recordings of oral endoscopic examinations for all horses referred to the Rossdales Equine Hospital for dental investigation from November 2006 to June 2009 were reviewed. Location of occlusal fissures in relation to bot...
Lindegaard C, Husted L, Ullum H, Fjeldborg J.Endoscopy of the upper airways of horses is used as a diagnostic tool and at purchase examinations. On some occasions it is necessary to use sedation during the procedure and it is often speculated that the result of the examination might be influenced due to the muscle-relaxing properties of the most commonly used sedatives. Objective: To evaluate the effect of detomidine (0.01 mg/kg bwt) and acepromazine (0.05 mg/kg bwt) on the appearance of symmetry of rima glottidis, ability to abduct maximally the arytenoid cartilages and the effect on recurrent laryngeal neuropathy (RLN) grade. Methods: ...
Schlater LR.Thirteen strains of a gram-negative, fermentative bacterium that produced gas from glucose were isolated from horses with a variety of clinical conditions. The morphological and biochemical characteristics of this bacterium are similar to those described for the family Pasteurellaceae. These strains appear to constitute a new taxon within the genus Pasteurella; however, the final taxonomic position of this group depends upon more detailed genetic studies. Case histories indicate that this bacterium may be a primary respiratory pathogen and may play a secondary role in various other disease con...
Higgins JC, Pusterla N, Pappagianis D.A retrospective study was performed to determine if there is an association between serological Coccidioides immitis antibody titres (IgG) and form/severity of coccidioidal disease in horses, and to identify trends in survival and treatment success based on the form of the disease. Data were obtained on horses with positive serological titres tested at the Coccidioidomycosis Serology Laboratory, School of Medicine, University of California, Davis from 1981 to 2004. Thirty-nine cases in which a diagnosis of coccidioidomycosis had been made were selected for inclusion. Six distinct categories we...
Stegelmeier BL, Davis TZ.Because most poisonings occur by toxin ingestion, the gastrointestinal system is the first exposed and, in most cases, it is exposed to the highest toxin concentrations. Consequently, enterocyte damage is common. However, because many toxins produce organ-specific damage, and enterocyte necrosis is easily confused with autolysis, many gastrointestinal lesions are overlooked or overshadowed by other clinical and pathologic changes. The objective of this work is to review several common toxins and poisonous plants that produce primarily gastrointestinal disease.
Spokes PJ, Marich AJ, Musto JA, Ward KA, Craig AT, McAnulty JM.An outbreak of equine influenza occurred in New South Wales in 2007. In addition to the local spread of the disease between bordering properties, windborne spread over several kilometres had been postulated as a possible method of transmission in this outbreak. This study aimed to describe potential modes of transmission for a property infected with equine influenza where no apparent epidemiological links to other infected properties were reported. Methods: A semi-structured questionnaire was administered to owners of affected properties. The questionnaire collected detailed transmission-risk ...
Lester GD, Bolton JR, Cambridge H, Thurgate S.The myoelectrical activity of the ileum, caecum and large colon was monitored from Ag-AgCl bipolar recording electrodes in four conscious 'parasite-naive' weanling foals. All foals were inoculated with 1000 infective 3rd-stage Strongylus vulgaris larvae and alterations to the myoelectrical activity observed. The frequencies of caecal and colonic spike bursts increased significantly in all post infection periods coinciding with assumed larval penetration into the intestinal mucosa and migration through the vasculature. Peaks in caecal and colonic activity occurred at Days 1 to 5 post infection....
van Rensburg IB, Jardine JE, Carstens JH, van der Walt ML.Specimens from the ileum, colon and rectum were aseptically collected from 50 consecutive horse carcases submitted for necropsy to the Department of Pathology, Faculty of Veterinary Science, University of Pretoria. These were bacteriologically examined for the presence of Salmonella. Seventeen of these were positive for Salmonella at one or more sites. Serotyping of the isolates revealed a dominance of Salmonella Hayindogo in these horses.
Bovell DL, Lindsay SL, Corbett AD, Steel C.Western blot analysis showed that sweat gland cells from freely sweating horses expressed the water channel aquaporin-5 (AQP-5). Immunohistochemistry revealed a strong AQP-5-like activity reaction at the apical membrane of the glandular secretory cells, which was absent from the surrounding myoepithelium and all other skin structures. In anhidrotic horses, AQP-5 was also found at the apical membrane of the luminal sweat gland cells, but the level of expression reduced with the length of time that the animal had displayed anhidrosis. The level of AQP-5 expression was substantially reduced in an...
Becher AM, Pfister K.In recent years more and more cases of anthelmintic resistant equine strongyles were reported. The latest developments are cases of resistance against macrocyclic lactones. In order to delay this process less anthelmintics and only those which have been previously tested for their efficacy on each individual farm should be used. During the grazing season 2008 faecal samples of 281 horses and 5 donkeys from 26 farms were analysed in the area of Salzburg. To 164 of these horses selective anthelmintic treatment was implemented. Every four weeks faecal samples from the 164 horses were quantitative...
Ramzan PH, Newton JR, Shepherd MC, Head MJ.Tibial stress fractures are an important cause of lameness in the Thoroughbred racehorse. While it is recognised that these injuries can vary in clinical presentation and radiographic or scintigraphic appearance, little has been done to quantify lesion severity. By contrast the scintigraphic grading of tibial stress fractures in human athletes is widely reported and assists in the selection of appropriate management regimes. Objective: To determine the relationship between scintigraphic grade, clinical severity and radiographic appearance of tibial stress fractures. Methods: The current study ...
Du Cheyne C, Chen Y, De Craene J, Thas O, De Spiegelaere W.Accurate tools to measure RNA integrity are essential to obtain reliable gene expression data. The reverse transcription quantitative PCR (RT-qPCR) based 3':5' assay permits a direct determination of messenger RNA (mRNA) integrity. However, the use of standard curves and the possible effect of PCR inhibitors make this method cumbersome and prone to variation, especially in small samples. Here we developed a triplex digital PCR (dPCR) 3':5' assay for assessing RNA integrity in equine samples as rapid and simple alternative to RT-qPCR. This dPCR assay not only provides a straight forward analysi...
Scott EA, Byars TD, Lamar AM.The hematologic and clinical effects of anticoagulation with warfarin were documented in 4 horses. All of the animals had thrombophlebitis (external jugular vein). Measures of coagulation were monitored, with a prothrombin time of 1.5 to 2.5 x base-line value being used as the effective range of anticoagulation. Recanalization was achieved in 2 of 4 cases. Hemorrhage, both subcutaneous and through a surgical incision, was a complication. Vitamin K1, an antidote to warfarin toxicosis, was administered intravenously to reverse anticoagulation and to control hemorrhage.
Buergelt CD, Greiner EC.Fibrosing granulomas were found in the liver and occasionally on the intestinal and diaphragmatic serosae and in the lung of 11 horses submitted for necropsy. Although these granulomas were considered incidental findings in most of the horses, they had caused liver failure in 1 horse. The granulomas typically were characterized by a dense collagenous core that frequently was mineralized. The periphery contained a rim of inflammatory cells. Only in 1 of the 11 horses was there evidence of an egg shell suggestive of schistosomes. Schistosomal eggs were not detected in the feces of the horses. Th...
el-Ashker MR.The present study was carried out to evaluate the role of oxidative stress in the pathophysiologic process of acute renal failure associated with exertional rhabdomyolysis (ER) in Egyptian horses. ER was tentatively diagnosed in 31 Baladi horses based on case history, physical examination findings and confirmed by elevation of plasma creatine kinase (CK) and urine myoglobin concentrations. According to severity of the condition, the diseased horses were categorized into two main groups; the first group included 18 horses with minimal clinical signs and plasma CK <60 000 IU/L; whereas, the seco...