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.
Steinbach TJ, Reischauer A, Kunkemöller I, Mense MG.A neonatal foal was presented with a 6.5-cm pedunculated mass arising from the upper deciduous incisors. The distal end was soft and covered by haired skin, whereas the proximal end was firm, covered with mucosal epithelium, and at the point of transection contained a fully developed tooth. Microscopically, the mass was covered by epidermis and mucosal epithelium and the remaining portion of the mass consisted of mature collagen, nonneoplastic fat and smooth muscle, and a single tooth within a bony socket. The mass is consistent with an oral choristoma and has features similar to those describ...
Bosch G, van Schie MJ, Back W.A keratoma is a rather uncommon disorder of the equine hoof that can lead to lameness. Few quantitative data exist about the prognosis of different treatment regimens. The outcome of 41 cases that were presented to the Department of Equine Sciences in the period 1995-2001 and that were treated according to different regimens was retrospectively evaluated. All horses showed lameness that could be attributed to the keratoma: 23 (56%) were treated surgically using a standardized procedure, while the other 18 (44%) were treated conservatively. Results were based upon 35 horses; 6 were lost to foll...
Dunkel B, Shokek AB, Wilkins PA.A neonatal foal with signs of rectal bleeding was diagnosed with an intraluminal rectal mass and intussusception on surgical exploration of the abdomen. Histologically, the mass consisted of cystic spaces lined by simple columnar epithelium with numerous goblet cells and was surrounded by thin bands of smooth muscle in a myxomatous stroma. Although the mass shared similarities with retrorectal cystic hamartoma (tailgut cyst) and juvenile polyps, described in human medicine, location and histologic findings were not entirely consistent with either condition.
Kania SA, Reinemeyer CR.Anoplocephala perfoliata has a prevalence as high as 60% in some geographical areas and has been associated with increased risk for serious conditions in the horse including bowel irritation, ileal impaction, and spasmodic colic. Identification of infected animals based upon detection of eggs in feces is labor intensive and unreliable. This study involved the development of a test for A.perfoliata coproantigen using an antigen capture enzyme linked immunosorbent assay (ELISA) and correctly distinguished between infected and uninfected animals in a trial with a small sample size.
Crevier-Denoix N, Ruel Y, Dardillat C, Jerbi H, Sanaa M, Collobert-Laugier C, Ribot X, Denoix JM, Pourcelot P.The objective of this study was to test the hypothesis that tendon echogenicity is associated with the material properties of the corresponding tendon site, especially in case of lesions, due to local changes in tendon matrix composition. Four normal and nine spontaneously injured equine superficial digital flexor tendons (SDFT) were isolated then ultrasonographically examined under tension, in a special device placed in a water bath. Ultrasonographic transversal images (7.5MHz linear transducer) of five segments along each tendon were digitized, and analyzed in order to measure the mean cross...
Mischke R, Junker J, Deegen E.The sensitivity of commercial prothrombin time (PT) tests was assessed based on a dilution series of equine pooled plasma (EPP) (experiment 1) and on 40 equine plasma samples with reduced activity of coagulation factors II, V, VII and X (experiment 2). Two different PT reagents (reagent 1, human placental thromboplastin; reagent 2, recombinant human tissue factor) were used according to the manufacturers' instructions (standard test, PT([ST])) and compared to a modified test procedure (modified test, PT([MT])) using sample dilution and fibrinogen addition. In all samples, sensitivity was lower...
Chan CP, Wan TS, Watkins KL, Pelsers MM, Van der Voort D, Tang FP, Lam KH, Mill J, Yuan Y, Lehmann M, Hempel A, Sanderson JE, Glatz JF, Renneberg R.Fatty acid-binding protein (FABP) holds promise for early detection of tissue injury. This small protein (15kD) appears earlier in the blood than large proteins after cell damage. Combined its characteristics of high concentration tissue contents and low normal plasma values provide the possibility of a rapid rise above the respective reference values, and thus an early indication of the appearance of tissue injury. A general review was presented on the current status of different types of FABP for the detection of tissue injury in patients with myocardial injury, brain injury and also in athl...
Seltenhammer MH, Heere-Ress E, Brandt S, Druml T, Jansen B, Pehamberger H, Niebauer GW.Equine melanoma shows striking features particularly with regard to clinical development in grey horses: in contrast to malignant melanoma in humans and in solid coloured horses that are characterized by early onset of metastasis, pigment cell tumours display almost benign clinical features in ageing grey horses. Through evolution, grey horses appear to be in a favourable position in regard to the biological behaviour of melanomas. Yet unknown factors inhibiting or retarding early melanoma metastasis may be responsible for this phenomenon. In this study, immunostaining profiles and histopathol...
Tydén E, Olsén L, Tallkvist J, Larsson P, Tjälve H.The intestinal enterocytes provide the initial site for cytochrome P450 (CYP)-mediated metabolism of orally absorbed xenobiotics. In man and some animal species, the CYP3A subfamily is highly expressed in the intestines and considered to be important in the first-pass metabolism of drugs and other xenobiotics. The aim of the present study was to investigate the mRNA expression, immunohistochemical localization and catalytic activity of CYP3A in the intestines of horse. Real-time RT-PCR analyses showed that the highest CYP3A mRNA expression was present in the duodenum with a decreasing level to...
Archer DC, Clegg PD, Edwards GB.A 21-year-old Arab gelding with clinical signs of acute peritonitis had a perforating ulcer on the mesenteric border of the jejunum which resulted in localised contamination of the abdomen with ingesta. The affected segment of jejunum was resected and the abdomen was lavaged extensively. Postoperatively, the gelding was treated with broad-spectrum antibiotics, non-steroidal anti-inflammatory drugs and intravenous fluids, but after four days it became acutely non-weight bearing on its right hindlimb, and a tendonitis of the lateral digital flexor tendon within the tarsal sheath was identified u...
Ihler CF, Venger JL, Skjerve E.The present prospective study included 106 horses referred to the Department of Large Animal Sciences, The Norwegian School of Veterinary Science, as non-responders to the initial colic treatment in general practise. In 14 of these cases a required surgical treatment was not performed due to economical or other reasons and were excluded from the study. Clinical and laboratory data were obtained at the arrival in the hospital. The outcome for all analyses was survival/ non-survival. A multivariable logistic regression was performed. The analyses were used in medically (46 horses) and surgically...
Ousey JC, Houghton E, Grainger L, Rossdale PD, Fowden AL.Progesterone (P4), pregnenolone (P5) and their metabolites are present in maternal plasma in pregnant mares. It is believed that one of these progestagens may maintain myometrial quiescence. The aims of this study were to identify specific progestagens in pregnant mares' plasma and determine whether these differed between mares with healthy or compromised pregnancies. Jugular blood samples were collected between 243 and 351 days gestation from 19 healthy Thoroughbred mares and 14 mares with placental pathology, including placentitis, and other clinical problems (uterine torsion/rupture, colic,...
Jin S, Issel CJ, Montelaro RC.We recently reported a highly protective attenuated live virus vaccine for equine infectious anemia virus (EIAV) based on a proviral construct (EIAVUKDeltaS2) with a genetically engineered mutation in the viral S2 gene that eliminates expression of this accessory protein. While the EIAVUKDeltaS2 vaccine provides protection from detectable infection by experimental challenge with highly virulent virus, the potential for commercial application of this vaccine is complicated by the fact that horses inoculated with the EIAVUKDeltaS2 vaccine strain become seropositive in various reference diagnosti...
Weishaupt MA, Wiestner T, Hogg HP, Jordan P, Auer JA.The study was performed to obtain a detailed insight into the load and time shifting mechanisms of horses with unilateral weight-bearing forelimb lameness. Reversible lameness was induced in 11 clinically sound horses by applying a solar pressure model. Three degrees of lameness (subtle, mild and moderate) were induced and compared with sound control measurements. Vertical ground reaction force-time histories of all four limbs were recorded simultaneously on an instrumented treadmill. Four compensatory mechanisms could be identified that served to reduce structural stress, i.e. peak vertical f...
Proudman CJ, Dugdale AH, Senior JM, Edwards GB, Smith JE, Leuwer ML, French NP.Mortality rates for horses that have undergone emergency abdominal surgery are higher than for other procedures. Here, multivariable modelling of data from 774 surgical colic cases is used to identify pre-operative and anaesthesia-related variables associated with intra- and post-operative mortality. Intra-operative mortality was significantly (P<0.05), and positively associated with heart rate and packed cell volume (PCV) at admission, and negatively associated with the severity of pain. Post-operative mortality increased with increasing age and PCV at admission. Draught horses, Thoroughbr...
Sebastian MM, Giles RC.Fibrocartilaginous embolic myelopathy was diagnosed in a 11-year-old, male, Tennessee Walking Horse by histopathological examination of the spinal cord after the horse was killed because of severe neurological dysfunction. Both ventral funiculi of C6 and C7 cervical spinal cord had extensive necrosis with blood vessels containing fibrocartilaginous emboli. A similar fibrocartilaginous embolus was observed in a single large spinal artery adjoining the vertebral leptomeninges.
Tomlinson JE, Blikslager AT.To determine whether ischemia and flunixin affect in vitro lipopolysaccharide (LPS) absorption in samples of the jejunum of horses. Methods: 12 horses. Methods: Horses were anesthetized, a midline celiotomy was performed, and the jejunum was located. Two 30-cm sections of jejunum (60 cm apart) were selected. One segment was designated as control tissue; ischemia was induced in the other segment for 120 minutes. Horses were then euthanatized. Mucosa from each jejunal segment was mounted on Ussing chambers and treated with or without flunixin. Tissues from 6 horses were used to assess permeabili...
Gudmundsdottir KB, Svansson V, Aalbaek B, Gunnarsson E, Sigurdarson S.Twenty isolates of Listeria monocytogenes associated with five confirmed and four suspected incidents of listeriosis in horses in Iceland were characterised by serotyping, pulsed-field gel electrophoresis and ribotyping. Semiquantitative estimates of the numbers of L monocytogenes were made on faeces from horses with clinical signs of listeriosis and on grass silage fed to them. Large numbers of L monocytogenes were often found in the faeces of horses with severe signs of disease. The 20 isolates could be divided into six genotypes, each incident involving only one genotype. One serovar 1/2a g...
Morley PS.Surveillance for nosocomial infection and disease is a critical component in an integrated and highly effective infection control program. Surveillance activities provide a sensory role to guide ongoing control practices so that they are focused and efficient. Without input from surveillance results, infection control practices are likely to be guided more by emotion and opinion than by data and evidence. This article discusses issues to be considered when developing effective nosocomial infection surveillance programs as well as the historical perspective of surveillance efforts for nosocomia...
Reed SM, Toribio RE.Equine herpesvirus infections in horses remain a significant cause of abortion and neurologic disease. These viruses are also responsible for mild signs of respiratory disease. The ability to establish latent infections with periodic reactivation or transmission to other horses is an important feature of these herpesviruses. One of the most unique aspects of this report is the description of horses demonstrating neurologic signs serving as the source of infection for other horses. Accurate diagnosis and better means of protection for horses remain problems facing veterinarians and horse owners...
Båverud V.C difficile has emerged as an important cause of diarrheic disease in horses. C difficile diarrhea is usually diagnosed in mature horses, mostly when they are treated with antimicrobials and hospitalized. It is important for clinicians at veterinary hospitals to have knowledge about the organism and the infection. To prevent C difficile diarrhea, judicious use of antimicrobials is important, as is minimizing different stress factors at the animal hospital or clinic. Infected horses must be isolated. Routine examination for C difficile and toxin A or B is recommended in horses with antibiotic-a...
Horín P, Smola J, Matiasovic J, Vyskocil M, Lukeszová L, Tomanová K, Králík P, Glasnák V, Schröffelová D, Knoll A, Sedlinská M, Krenková L....Polymorphic markers identified in the horse genes encoding the interleukin 12 p40 subunit, interferon gamma, tumor necrosis factor receptor 1, and inducible nitric oxide synthase were identified and tested, along with additional markers, for associations with two important horse infections: Rhodococcus equi and Lawsonia intracellularis. Eight immune response-related and 14 microsatellite loci covering 12 out of 31 equine autosomes were used for the association analysis. Markers located on horse Chromosomes Eca10 and 15 were significantly associated with the presence of high numbers of R. equi ...
Weese JS.Because nosocomial and zoonotic diseases are inherent and ever-present risks in veterinary hospitals, proactive policies should be in place to reduce the risk of sporadic cases and outbreaks. Policies should ideally be put in place before disease issues arise, and policies should be effectively conveyed to all relevant personnel. Written policies are required for practical and liability reasons and should be reviewed regularly. Although no infection control program can eliminate disease concerns, proper implementation of barrier precautions and isolation can reduce the exposure of hospitalized...
Cohen ND, Lester GD, Sanchez LC, Merritt AM, Roussel AJ.To determine factors associated with development of postoperative ileus (POI) in horses undergoing surgery for colic. Methods: Prospective case-control study. Methods: 251 horses undergoing colic surgery, of which 47 developed POI. Methods: Signalment, history, clinicopathologic data, pre- and postoperative treatments, lesions, complications, costs, and outcome were recorded for all horses during hospitalization. Results: Variables associated with increased odds of POI included small intestinal lesion, high PCV, and increased duration of anesthesia. There was modest evidence that pelvic flexur...
Lehner AF, Hughes CG, Karpiesiuk W, Harkins JD, Dirikolu L, Bosken J, Camargo F, Boyles J, Troppmann A, Woods WE, Tobin T.Amitraz (N'-(2,4-dimethylphenyl)-N-[[(2,4-dimethylphenyl)imino]methyl]-N-methyl-methanimidamide) is an alpha-2 adrenergic agonist used in veterinary medicine primarily as a scabicide- or acaricide-type insecticide. As an alpha-2 adrenergic agonist, it also has sedative/tranquilizing properties and is, therefore, listed as an Association of Racing Commissioners International Class 3 Foreign Substance, indicating its potential to influence the outcome of horse races. We identified the principal equine metabolite of amitraz as N-2,4-dimethylphenyl-N'-methylformamidine by electrospray ionization(+...
Schuler LA, Khaitsa ML, Dyer NW, Stoltenow CL.To characterize an outbreak of West Nile virus (WNV) infection in horses in North Dakota in 2002, evaluate vaccine effectiveness, and determine horse characteristics and clinical signs associated with infection. Methods: Retrospective study. Methods: 569 horses. Methods: Data were obtained from veterinary laboratory records, and a questionnaire was mailed to veterinarians of affected horses. Results: Affected horses were defined as horses with typical clinical signs and seroconversion or positive results of virus isolation; affected horses were detected in 52 of the 53 counties and concentrate...
Perrier M, Manso-Díaz G, Dunkel B.Trigeminal nerve-mediated head-shaking (TNMH) in horses is a diagnosis made by exclusion. Computed tomography (CT) is frequently used to identify any disease process that could cause the clinical signs of head-shaking. Although abnormalities are frequently identified, it is unknown whether treatment of these conditions improves clinical signs. Objective: To ascertain the clinical significance of CT findings in horses presented with a complaint of head-shaking. Methods: Retrospective case series. Methods: CT and patient records were reviewed and all abnormal findings and any treatments subseque...
Albanese V, Munsterman A, Klohnen A.Enterolithiasis is a well-documented cause of colic in horses, especially in some geographic areas such as California and Florida. This retrospective case-control study aims at comparing the prevalence of gastric ulcers in horses affected by enterolithiasis to that in horses affected by other types of large intestinal obstruction. Two hundred and ninety-six horses were included in the study sample. Horses that had surgery for the removal of one or more enteroliths were included in the study as cases. Patients that had surgery for large intestinal simple obstructions other than enterolithiasis ...
Jesty SA, Reef VB.This article first reviews cardiovascular infections, including endocarditis, myocarditis, vasculitis, and pericarditis. It then addresses what is known at this stage about the effects of sepsis on the cardiovascular system. Some information is provided from current human literature to familiarize the reader with the diagnostics and therapeutics that may eventually be used in equine practice as well.
Reilly L, Habecker P, Beech J, Johnston J, Sweeney C, Hamir A.Abscess of the pituitary gland is a rare condition which has been
described in man (Domingue and Wilson 1977; Ahmed et al. 1989),
ruminants (Taylor and Meads 1963; Moriwaki er al. 1973; Lomas and
Hazell 1983; Perdrizet and Dinsmore 1986) and one horse
(Rumbaugh 1977). The some of infection may be either direct
extension from an adjacent focus or haematogenous spread from a site
elsewhere in the body. In man, pituitary abscess may result from
meningitis, sphenoid sinusitis (Selose et al. 1980), and osteomyelitis
(Rongetti and Daniels 1950). A review of 20 cases of pituitary abscess
in ...
Robinson B, Gummow B.A disease outbreak investigation was conducted in western Queensland to investigate a rare suspected outbreak of pyrrolizidine alkaloid (PA) toxicosis in horses. Thirty five of 132 horses depastured on five properties on the Mitchell grass plains of western Queensland died in the first six months of 2010. Clinical-pathological findings were consistent with PA toxicosis. A local variety of Crotalaria medicaginea was the only hepatotoxic plant found growing on affected properties. Pathology reports and departure and arrival dates of two brood mares provided evidence of a pre wet season exposure ...
Matsui K, Amada A, Sawazaki H.Electrocardiographic observation in 10 Thoroughbred horses has been carried out from fetal stages to 12 months after birth. In this observation a filly out of 10 foals at a resting state showed second-degree atrioventricular {A-V) block with sinus arrhythmia after 2.5 months of age. The number of dropped beats and the irregularity of sinus arrhythmia in these blocks were affected by the atrial rate, and several variations of Wenckebach phenomenon were shown under the influence of the artial rate. Electrocardiographic characteristics of second-degree A-V block in the present filly might be simi...
Held JP, Oliver JW.A study was designed to assess the secretory response of thyroid glands in horses to an economically feasible dose (5 IU) of thyrotropin injected IV, and to establish valid blood sampling periods in cases in which thyroxine concentrations were different from base-line values. Significant (P less than 0.001) response (doubling or near-doubling of base line) occurred as early as 3 hours after thyrotropin administration, with peak response at 4 to 5 hours. It was concluded that administration of 5 IU of thyrotropin is economical and effective in the horse, with collection of a second blood sample...
Sebastian M, Gantz MG, Tobin T, Harkins JD, Bosken JM, Hughes C, Harrison LR, Bernard WV, Richter DL, Fitzgerald TD.During 2001, central Kentucky experienced acute transient epidemics of early and late fetal losses, pericarditis, and unilateral endophthalmitis, collectively referred to as mare reproductive loss syndrome (MRLS). A toxicokinetic/statistical analysis of experimental and field MRLS data was conducted using accelerated failure time (AFT) analysis of abortions following administration of Eastern tent caterpillars (ETCs; 100 or 50 g/day or 100 g of irradiated caterpillars/day) to late-term pregnant mares. In addition, 2001 late-term fetal loss field data were used in the analysis. Experimental dat...
Victor S, Lampa E, Rask Andersen A, Gafvelin G, Grönlund H, Elfman L.Horse allergens are less studied than allergens from other furry animals and these allergens must be evaluated to understand the complexity of allergy to horses. The aims of this study were to develop assays for the horse allergens Equ c 1 and Equ c 2 in dander and saliva and to determine their levels in ten horse breeds. The study also included a comparison of these findings with previous results on the levels of Equ c 4 performed on the same study population. The study population included 170 horses from 10 horse breeds including American Curly and Russian Bashkir horse, which have been sugg...
Doxey DL, Milne EM, Harter A.The outcome for 35 horses with chronic dysautonomia which were kept in the hospital at the Royal (Dick) School of Veterinary Studies and subsequently returned to their owners is recorded. They constituted 42.7 per cent of the 82 chronic cases seen between 1991 and 1994; the other 47 horses were euthanased while in hospital. Of the 35 animals returned to their owners four died and 27 were available for follow up; of these 27, 12 were working competitively and six were being trained for future competitive work. It takes at least a year before it is clear whether a horse can compete successfully ...
Johnson DJ, Ostlund EN, Palmer TJ, Fett KL, Schmitt BJ.Semen from an apparently healthy 4-year-old American Quarter Horse was submitted to the National Veterinary Services Laboratories for Equine arteritis virus isolation. Visual inspection of the semen sample upon arrival noted it was unusually yellow in color. The semen sample was inoculated onto cell monolayers, and cytopathic effect was observed 5 days postinoculation. The resultant isolate tested negative for Equine arteritis virus, and was subsequently identified as Equine rhinitis A virus. Equine rhinitis A virus has been isolated from horse urine, but has not been described in stallion sem...
Rodríguez A, Peña L, Flores JM, González M, Castaño M.This study was undertaken to investigate the presence of neuroendocrine cells (N.E.C.) by immunocytochemical means in equine lungs during three distinct evolutionary periods: fetal, neonatal and adult. The authors identified bombesin, somatostatin and calcitonin secretory cells. In the fetal lungs the N.E.C. were located in the interstitial tissue and exhibited greater immunoreactivity to bombesin than to the other two neuropeptides studied. A large number of calcitonin-producing cells and a smaller number of bombesin-positive cells were seen in the bronchial and bronchiolar epithelium of newb...
Callan MB, Giger U, Oakley DA, Scotti MV, Shofer FS.In veterinary medicine, PCV determined by centrifugation of blood in a microhematocrit tube is the most common clinical test used to initially assess and monitor anemic and polycythemic animals. In contrast, blood hemoglobin (Hb) concentration, rather than PCV, is generally determined in human patients. One automated system photometrically measures blood Hb concentration after conversion of Hb to azide methemoglobin without dilution and was found to be a simple and accurate instrument for use in human medicine. We evaluated the system for its accuracy in measuring blood Hb concentration in ani...