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.
Williams H, Richards CM, Konfortov BA, Miller JR, Tucker EM.In a study of 35 horse-mouse heterohybridoma cell lines, synteny in the horse was found between LDHB, PEPB and IGF1 and between NP, MPI and IDH2. A synteny between ADA and PEPC was also indicated. The loci for horse immunoglobulin light chain (IgL) genes and for LDHA were independent.
Green SL.With the continued increase in the number of wildlife rabies cases reported across the United States and Canada, this disease will remain a threat to the horse as the potential for exposure to infected wildlife and other domestic animals is likely to also increase. Because there are no rapid, definitive antemortem diagnostic tests, the tentative diagnosis is based upon the variable and sometimes nonspecific clinical signs. Although the CSF analysis may be helpful in some cases, it may not be abnormal. Nor is collection of the specimen always practical in the field situation. The FAT on neural ...
Madigan JE.Equine ehrlichiosis is a seasonal disease of horses first reported in 1969. Clinical signs in horses include high fever, depression, partial hypophagia, anorexia, limb edema, petechiation, icterus, ataxia, and reluctance to move. Hematologic changes include leukopenia, thrombocytopenia, icterus, anemia, and inclusion bodies, principally in neutrophils and occasionally in eosinophils. Diagnosis is made by clinical signs and observing characteristic morulae in a blood smear with standard Wright's stain. Mortality is low unless secondary infection develops or injury occurs as a result of incoordi...
Sloet van Oldruitenborgh-Oosterbaan MM, van Duijkeren E.Salmonellosis is a worldwide problem of both men and animals. Equine salmonellosis is an increasing problem and a review of the recent knowledge is given. Etiology, symptomatology, diagnostic procedures, therapy and prevention are discussed.
Lubczyk B, Nothelfer HB.A case of generalized equine leucosis is presented. The most important clinical signs were cachexia, loss of condition, fever, tachycardia, subcutaneous tumors and severe lameness accompanied by edema of the right thoracic limb. Hematology showed anemia and neutrophilia; clinical biochemistry indicated hypalbuminemia, hyperphosphatemia and hyperfibrinogenemia. Necropsy revealed multiple tumors throughout the body which mainly originated from lymph nodes. Histopathologically the tumors consisted of two cell-types: a. uniform lymphocytoid cells with a highly infiltrative growth pattern; b. heter...
Wilson WD.Influenza continues to be one of the most important diseases of horses despite the availability and widespread use of equine influenza vaccines for almost 30 years. In recent years, infection with the influenza A/equine/2 subtype has become endemic in the equine populations of North America, Europe, and Scandinavia. Continued antigenic drift of field virus has compromised the efficacy of vaccines, most of which contain antigens prepared from influenza viruses isolated more than 10 years ago. This article reviews the history, virology, epidemiology, pathogenesis, immunology, clinical presentati...
Balazs EA, Denlinger JL.Viscosupplementation is a new medical concept that has as its therapeutic goal the restoration of rheological homeostasis in pathological structures such as osteoarthritic joints. When the normal viscoelasticity of a solid tissue compartment or the elastoviscosity of a liquid tissue compartment is decreased under pathological conditions, normal function and regenerative processes are impaired. By introducing viscosupplementary devices, the normal rheological state of such compartments is restored or augmented. These devices stay in the tissue compartment for various periods of time, depending ...
Firth EC, Alley MR, Hodge H.Two cases of Rhodococcus equi infection in foals are described, in which osteomyelitis was a feature. Because rhodococcal infection is usually low grade and chronic, and because the signs of early metaphysitis can be subtle, any articular or periarticular swelling in a foal from a farm with a history of rhodococcosis should be strongly suspected to be associated with R equi until proven otherwise.
Gregg AS, Jones RS, Snowdon SL.A fault in the assembly of a Matrix Large Animal Circle anaesthetic machine resulted in reversal of fresh gas flow through the vaporizer. The fault was discovered only after the sudden development of excessive depth of anaesthesia in two equine patients. Laboratory investigations were conducted to determine the effect of flow reversal on vaporizer output. Results indicated that output concentration was approximately doubled under these conditions.
Steiner N, Lindner A.By means of a survey, the reproductive rate of mares and the foal losses in ten Thoroughbred, Saddlebred and Pony studs in Germany, mainly from North-Rhine-Westfalia, were collected and evaluated. Data for the survey were recorded for 1985-1990. The study also examined the hygienic management in the surveyed studs, and the morbidity rate of suckling foals was obtained for 1990. In addition to the survey questionnaire each stud was visited once. Two studs of each horse group were visited several times every week from March to August in order to evaluate as exactly as possible the husbandry and ...
Boujon CE, Bestetti GE, Meier HP, Straub R, Junker U, Rossi GL.Clinico-pathological correlations in horses with pituitary adenomas are poorly understood. This paper describes the functional and morphological features of five cases of equine pituitary adenoma and of a case of multinodular pituitary hyperplasia. New findings reported include immunoreactivity for beta-lipotropin (beta-LPH), beta-melanocyte-stimulating hormone (beta-MSH), gamma 3-MSH, prolactin (PRL), and follicle-stimulating hormone (FSH) in neoplastic cells of the pituitary adenoma; and, in the multinodular hyperplasia, beta-LPH, beta-endorphin (beta-END), alpha-MSH, beta-MSH, gamma 3-MSH a...
House JA.AHS is a noncontagious vector-borne disease of Equidae caused by Orbiviruses. Species susceptibility in decreasing order is horses, mules, donkeys, and zebras. The main vectors of AHS are culicoides. The disease is endemic in sub-Saharan Africa, but epizootics have occurred outside of this area on several occasions. The most recent outbreaks outside of the endemic area were in Spain, Morocco, and Portugal between 1987 and 1990. AHS causes mortality up to 95% and is classically divided into four clinical forms: the pulmonary, cardiac, mixed, and horse fever forms. Pathologic changes are subcuta...
House JA.AHS is a noncontagious vector-borne disease of Equidae caused by Orbiviruses. Species susceptibility in decreasing order is horses, mules, donkeys, and zebras. The main vectors of AHS are culicoides. The disease is endemic in sub-Saharan Africa, but epizootics have occurred outside of this area on several occasions. The most recent outbreaks outside of the endemic area were in Spain, Morocco, and Portugal between 1987 and 1990. AHS causes mortality up to 95% and is classically divided into four clinical forms: the pulmonary, cardiac, mixed, and horse fever forms. Pathologic changes are subcuta...
Ohmuro K, Okada K, Satoh A, Murakami K, Satake S, Asahina M, Numakunai S, Ohshima K.A thoroughbred horse, gelding, gray color, aged 19 years old had cutaneous melanomas from the root to the middle of the tail, and throughout the connective tissues of the whole body. Histologically, the tumors were diagnosed as mature melanotic melanomas characteristically deposited with abundant melanin pigment. Examined with an electron microscope, melanosomes were electron opaque without internal structure (stage IV), or as mature granular and lamellar types. Most of them were fused with each other, and formed compound melanosomes, which was similar to internal melanin aggregates in shape. ...
Laegreid WW, Skowronek A, Stone-Marschat M, Burrage T.There are three clinicopathologic syndromes associated with African horsesickness (AHS) virus infection in horses. These different forms of AHS (pulmonary, cardiac, and fever forms) vary in the organs affected, the severity of lesions, time of onset of clinical signs and mortality rates. We have studied the effects of infection with three cell culture passaged variants of AHS virus in naive North American horses. One of these viruses, AHS/4SP, consistently caused the pulmonary form of AHS with rapid onset of severe pulmonary edema and 100% mortality. A second variant, AHS/9PI, resulted in sign...
House JA.AHS is a noncontagious vector-borne disease of Equidae caused by Orbiviruses. Species susceptibility in decreasing order is horses, mules, donkeys, and zebras. The main vectors of AHS are culicoides. The disease is endemic in sub-Saharan Africa, but epizootics have occurred outside of this area on several occasions. The most recent outbreaks outside of the endemic area were in Spain, Morocco, and Portugal between 1987 and 1990. AHS causes mortality up to 95% and is classically divided into four clinical forms: the pulmonary, cardiac, mixed, and horse fever forms. Pathologic changes are subcuta...
Ross MW, Gentile DG, Evans LE.Transoral axial division was performed, using endoscopic guidance, in 20 horses with epiglottic entrapment. Mean age of affected horses was 3 years (range, 2 to 5 years), and there were 18 Standardbreds and 2 Thoroughbreds. Standardbreds and female horses were significantly overrepresented when compared with a reference population. Upper respiratory noise prompted endoscopic examination before surgery in 16 horses, but noise was not heard in 4 horses. Ten horses had entrapment by thin tissue without ulceration, 6 horses had entrapment by thin tissue with small, partial-thickness ulceration, 3 ...
Ostlund EN.Two viruses, EHV-1 and EHV-4, are now known to be responsible for disease conditions formerly considered caused by "equine rhinopneumonitis virus." Although these viruses share several laboratory and clinical features, they differ in epidemiology and pathogenic potential. EHV-4 is primarily associated with clinical respiratory disease, whereas EHV-1 is more frequently isolated from aborted fetuses, sickly foals, and neurologic cases. Both viruses frequently establish latent infections, but the relevance of latency to clinical disease is unclear. Diagnosis based on identification of the pathoge...
Moll HD, Schumacher J, Dabareiner RM, Slone DE.Three horses underwent exploratory celiotomy because of signs of acute abdominal pain. At surgery, all horses were diagnosed as having left dorsal displacement of the large colon. Each surgery was complicated by fibrous adhesions of the spleen to the body wall. All horses had previously undergone abdominal surgery for colic. In these cases, it appeared that the left large colon displaced cranially and then entered the renosplenic space from a cranial to caudal direction. Adhesions of the spleen to the body wall would prevent correction of left dorsal displacement of the large colon by the roll...
Green SL.Vesicular stomatitis (VS) is a viral disease of livestock that results in vesicles and ulcerations on the teats, oral mucosa, tongue, and coronary bands. All three main serotypes of the VS virus can infect the horse. Although VS does not have a major impact on the equine industry, it is clinically identical to the other more economically devastating vesicular diseases of cattle and swine and can produce influenza-like symptoms in humans. VS in horses is reportable, as are all vesicular diseases of livestock.
Hagebock JM, Chieves L, Frerichs WM, Miller CD.The agar gel immunodiffusion (AGID) and indirect fluorescent antibody (IFA) assays were evaluated as supplemental tests to the complement-fixation (CF) test, the official US importation certification test for dourine in equids. The American stabilate (n = 10 animals) or the Canadian stabilate (n = 6 animals) of Trypanosoma equiperdum cultured in rat blood was administered by catheterization and infusion in the urogenital tract of 16 equids. To assess parasitemia and serologic responses by use of the CF, AGID, and IFA tests, a total of 787 serum and blood samples were obtained from equids befor...
Spier SJ.Salmonellosis is the most common infectious cause of diarrhea or colitis in horses. It can be associated with high fatality rates in patients with compromised host defenses. The increasing incidence of infection and antimicrobial resistance present a challenge for the practicing veterinarians. The epidemiology and pathogenesis of salmonellosis are reviewed. Diagnosis, treatment, and control of disease are discussed.
Bernard WV, Williams D, Tuttle PA, Pierce S.A Thoroughbred foal that was born after 305 days of gestation was referred 6 hours after birth. On initial examination, the foal was alert, but weak and unable to stand. Heart rate was 150 beats/min, respiratory rate was 48 breaths/min, and rectal temperature was 33 C. Leukocytosis was detected (26,000 WBC/microliters). Dysuria and passage of red urine was observed approximately 30 hours after admission. Urine collected by free catch had a 3+ reaction for blood on dipstick analysis. Examination of Warthin Starry-stained sections of allantochorion revealed organisms morphologically characterist...
Hawkins JF, Bowman KF, Roberts MC, Cowen P.Peritonitis was diagnosed in 67 horses between 1985 and 1990: 14 horses developed septic peritonitis after intestinal rupture, 25 horses developed peritonitis after abdominal surgery, and 28 horses had peritonitis not associated with intestinal rupture or abdominal surgery. Forty of 67 horses (59.7%) did not survive. Nonsurvivors had higher heart rates (P = 0.01), RBC count (P = 0.039), serum creatinine concentration (P = 0.036), PCV (P = 0.007), and anion gap (P = 0.005); lower venous blood pH (P = 0.002); and a greater number of bacterial species cultured from peritoneal fluid samples (P = 0...
Scholes SF, Vaillant C, Peacock P, Edwards GB, Kelly DF.Ileal biopsies were obtained from 18 horses with grass sickness, 15 horses with other alimentary disease and three horses without gastrointestinal disease. Samples of small intestine were also obtained from nine cases of obstruction due to small intestinal strangulation. Histological examination revealed that severe enteric neuropathy in the absence of other significant morphological changes was confined to the horses with grass sickness.
McGorum BC, Dixon PM, Halliwell RE, Irving P.A comparison was made of the cellular and molecular components of bronchoalveolar lavage fluid (BALF) harvested from the left and right diaphragmatic lobes, the accessory lobe of the right lung and the apical lobe of the left lung, of seven control horses and six horses with symptomatic chronic obstructive pulmonary disease (COPD). Neither control nor symptomatic COPD affected horses showed significant regional differences in BALF recovery volumes, total and differential BALF cell counts, albumen adjusted total and absolute BALF cell counts, total and absolute pulmonary epithelial lining fluid...
Fadok VA.Abstract- Urticarial eruptions, with or without pruritus, are common lesions in horses. The pathogenesis of these lesions can include immunological and other mechanisms. Research in the human field suggests that the mast cell co-ordinates the urticarial response by releasing a complex array of inflammatory mediators. Other cells, including the neutrophil, the eosinophil and the macrophage, may also play a role in the development of wheals. Elucidation of the role of many of these cells and mediators in the evolution of urticaria is only just beginning. Successful treatment of this dermatologic...
McDonald GK.A six year old Percheron mare was presented with a history of spontaneous unilateral epistaxis of 24 hours duration. The blood one stage prothrombin and partial thromboplastin times were markedly prolonged. A diagnosis of moldy sweetclover poisoning was made on the basis of the history and clinical and laboratory findings. A single whole blood transfusion and four daily intravenous injections of vitamin K(3) proved to be a successful treatment.
de la Rúa-Doménech R, Mohammed HO, Cummings JF, Divers TJ, de Lahunta A, Valentine B, Summers BA, Jackson CA.We have conducted an ambidirectional study to estimate the incidence of equine motor neuron disease (EMND) in the northeastern US. The clinical and pathological features of EMND are similar to those described in human motor neuron disease. We have also collected data on all EMND cases reported in the US and described the geographic distribution of the disease. To identify factors associated with the risk of EMND, the authors assembled 163 control horses from the population in which cases were identified. The significance of association between the hypothesized factors and the risk of EMND was ...
Murray MJ.Hypothyroidism was diagnosed in a neonatal Thoroughbred foal that was weak, hypothermic, and septicemic. Administration of thyroid-releasing hormone elicited attenuated increases in concentrations of free and total triiodothyronine and thyroxine, as compared with a clinically normal, age-matched foal. The foal died of apparent respiratory insufficiency, pre- and postmortem findings compatible with hypothyroidism included hypothermia, large thyroid glands with distended, colloid-filled follicles, and severe, diffuse atelectasis, with thickened alveolar septae and degenerating alveolar squamous ...
Beelitz P, Rieder N, Gothe R.In this epidemiological study 30 mares and their foals from seven farms in Upper Bavaria were investigated. Eimeria-leuckarti-oocysts were found in 24 foals (80%), but only in one mare. Oocysts were first detected 28 days post partum at the earliest and 191 days post partum at the latest. In foals, excretion of oocysts usually occurred intermittently with coproscopically negative intervals of up to 15 weeks, and was most frequent in June (8 foals), July (17 foals), and August (10 foals). With the exception of two animals which had mild diarrhoea, the oocyst-shedding foals showed no clinical si...
Allen DA, Schertel ER.Shock has been described and defined by the inciting cause. This method of categorization does little to clarify common pathophysiologic changes known to occur regardless of the etiology. Each type of shock involves different stages that are determined by the inciting cause, its duration, severity of the initial result, susceptibility of the patient, and adequacy of treatment.
Wawrzykowski J, Rapacz-Leonard A, Wiącek D, Kankofer M, Janowski T.Protein profile of the placenta expresses its function and maintenance. Any alterations can be reflected in qualitative and quantitative changes in this profile. The aim of the present study was the evaluation of protein profile in the placenta of mares suffering from the retention of foetal membranes (FMR) by two separation methods and the comparison with physiologically released tissues. Placentas from 14 healthy, heavy draft mares were collected immediately after the expulsion of newborn. Tissues after homogenization and staining with fluorescent dyes were subjected to electrophoretic as we...
Brumbaugh GW, Sumano López H, Hoyas Sepúlveda ML.Each horse with laminitis is presented to the veterinarian at a different stage in progression of the condition and with varying severity. The pathogenic timing is often unknown and is difficult to determine. Because timing and severity are related to both the lesion's severity and responsiveness to treatment, these factors are critical to treatment selection and success. It is erroneous to assume that each horse with laminitis should receive each treatment. It is therefore important to ascertain as logically and objectively as possible the pathophysiological stage of development of each horse...
Weaver BM, Lunn CE, Staddon GE.Muscle perfusion was studied in conscious and anaesthetised horses by monitoring the clearance of a locally injected bolus of saline containing radioactive xenon (133Xe). The mean of all the measurements made from the brachiocephalicus and semimembranosus muscles in conscious subjects was 1.29 ml/min/100 g while in anaesthetised subjects it was 0.40 ml/min/100 g. The significance of these results is discussed in relation to the clinical occurrence of post anaesthetic myositis.
Thomson P, Toro J, Lara F, Hernández D, Aros K, Valenzuela-Lopez N.We present the first case of rhinopharyngitis due to Aspergillus fumigatus in a purebred Chilean horse. Clinically, manifested mucopurulent discharge from both nostrils, inflammation of the nasal, ocular, and ear mucosa; associated with decay and hyporexia. Based on the clinical signs and analysis of the mycological and molecular transtracheal aspirate sample, the present case was diagnosed as Aspergillus fumigatus rhinopharyngitis. After the antifungal susceptibility test, oral itraconazole treatment was maintained for 45 days, showing no clinical sign.
Smith BP.Salmonellosis in horses may result in fever, anorexia, and depression without concurrent diarrhea or other obvious gastrointestinal abnormalities and should be considered in cases of fever of unknown origin. The syndrome also is characterized by neutropenia, usually with a left shift, and growth of small numbers of salmonella from feces cultured in selenite enrichment broth. Repeated culturing may be necessary to isolate the organism. All six affected horses of this report recovered in 3 to 7 days without specific therapy.
Borst GH, van der Weij PJ, Vos JH.Acute idiopathic gastric rupture resulted in sudden death of a 4.5-months-old healthy Friesian foal. No morphological lesions were present which could explain the preceding gastric impaction. In this case hypodypsia may have been (partially) responsible for the impaction as only a mechanical drinking apparatus, unsuitably for horses, was available.
Roethlisberger-Holm K.Recording of intratracheal pressure during exercise as a method for evaluating upper airway obstruction in the horse has previously been carried out on the treadmill. In the present study the method was applied to normal horses, outdoors under field conditions, to assess its usefulness for analysis of respiratory problems mainly occurring under racing conditions. The horses examined performed a standardized exercise test during which the intratracheal pressure was recorded with a tape recorder receiving amplified signals from a transducer connected to a percutaneously inserted intratracheal ca...
Civello ANE, Dunkel B, Summers BA, Martineau HM.A neurofibroma of granular cell subtype is described in a 7-year-old horse. The horse had a 3-month history of ataxia affecting the forelimbs and hindlimbs, suggesting a C1-C6 neuroanatomical localization. Post-mortem examination revealed an intradural mass arising from the right sixth cervical spinal nerve and compressing the spinal cord. Histologically, the mass was composed largely of wavy spindle cells (a mixture of Schwann cells, perineurial cells and fibroblasts) intimately associated with ropy collagen fibres. Approximately 25% of the spindle cells were swollen and contained densely-pac...