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.
Dirscherl P, Grabner A, Buschmann H.As basophils are the major effector cells of allergic reactions, confirmation of the allergic etiology of chronic obstructive pulmonary disease (COPD) was sought by the demonstration of a specific in vitro response of equine basophilic blood cells to some potential allergens (Aspergillus, Cladosporidium, Mucor, Penicillium, extracts of dust particles of hay and straw). The allergen induced degranulation of basophils and the histamine and protease release from basophils during incubation with the allergens were tested. By evaluating the results obtained from 14 COPD horses and eight controls it...
Kaji Y, Taniyama H, Matsukawa K, Okada H, Tsunoda S, Tagami M, Akita H.Nodular hepatic lesions caused by larval Echinococcus multilocularis were found in a four-year-old female thoroughbred race horse born and raised in Hokkaido. Before detection of the infection, the infected animal was transported around Honshu for racing. The present disclosure of hydatidosis in a race horse raises concern over the potential danger of spreading the infection throughout Japan by horses possibly infected in Hokkaido.
Johnson PJ, Goetz TE.A 10-month-old Standard-bred colt was examined because of weight loss, fever, and extensive subcutaneous edema of the ventral aspects of its trunk. Diagnosis of granulomatous enteritis was based on D-xylose malabsorption, hypoproteinemia, and rectal mucosal biopsy. Campylobacter fetus subsp fetus was cultured from jugular venous blood when the horse was admitted to the hospital and 24 hours later. Appropriate antimicrobial agents and glucocorticoids failed to effect clinical remission. After euthanasia, granulomatous enteritis was confirmed at necropsy but C fetus subsp fetus was not isolated ...
Aguilera-Tejéro E, Pascoe JR, Amis TC, Kurpershoek CJ, Woliner MJ.A rebreathing method for measurement of pulmonary diffusing capacity for carbon monoxide (DLCO) and functional residual capacity (FRC) was evaluated in conscious horses. Horses were manually ventilated through an endotracheal tube, using a custom-made syringe filled with a gas mixture containing 18-carbon monoxide (18CO) and helium (He). The 18CO and He concentrations were continuously monitored by use of a mass spectrometer connected to the rebreathing circuit. Values for DLCO and FRC were calculated from changes in the concentration of these 2 gases. In 11 Thoroughbreds, mean (+/- SD) DLCO w...
Hoffman AM, Viel L, Prescott JF.Despite the high incidence of distal respiratory tract infection of undetermined cause on farms, to our knowledge, the microbiologic effects of conventional antimicrobial treatment for this condition have not been studied. We evaluated the possible pathogenic role of bacterial isolates from the distal airways of foals with clinical respiratory tract disease, by correlating changes in their numbers (increase or decrease) with clinical, endoscopic, and pulmonary cytologic signs of disease resolution during treatment with antimicrobial drugs. We also determined qualitative changes in in vitro ant...
Dabareiner RM, Sullins KE, Snyder JR, White NA, Gardner IA.Effects of intraluminal distention (25 cm of H2O, 120 minutes) and subsequent decompression (60 minutes) on intramural vascular patterns of the small intestine was evaluated in 7 anesthetized horses. Intraluminal distention (25 cm of H2O, 120 minutes) was created in 2 jejunal segments in each horse. Experimental and control segments were removed either immediately after the experimental period or after 60 minutes of decompression. The vascular system of experimental and control jejunal segments was lavaged with NaCl, then was injected with a blue-colored radiopaque medium for microangiography ...
Holyoak GR, Giles RC, McCollum WH, Little TV, Timoney PJ.The nature and extent of changes associated with equine arteritis virus (EAV) infection of the reproductive tract was documented in 21 prepubertal and 15 peripubertal colts. This study was part of an investigation into the relationship between stage of reproductive tract maturity and susceptibility to the experimental establishment of persistent infection with EAV. After intranasal challenge with a field isolate of EAV, all colts developed clinical signs of equine viral arteritis (EVA) from which they recovered rapidly. Clinical signs during the acute phase consisted of fever, serous to mucopu...
Lyons ET, Tolliver SC, Drudge JH, Granstrom DE, Collins SS.During the period 28 February-1 July 1992, fecal samples were collected and examined for eggs of Strongyloides westeri once from each of 382 horse foals (364 Thoroughbreds, 16 Standardbreds, one Lippizaner, and one draft-type horse) in central Kentucky. Ages of the foals at the time of sampling ranged from 7 to 63 days (mean 22 days). The nine farms in the study were considered to have overall excellent deworming programs. None of the foals had been treated with an antiparasitic compound before the study. Eggs of S. westeri were found in 6% (22 of 382) of the foals on 78% (7 of 9) of the farms...
Fairbairn SM, Page CP, Lees P, Cunningham FM.Previous studies have shown that bronchoalveolar lavage fluid from horses with allergic respiratory disease and showing clinical symptoms contains increased numbers of neutrophils. In some cases, the eosinophil count is also increased. In this study the time course of changes in lung function and the accumulation of radiolabelled leucocytes and platelets in the lungs of allergic and normal horses has been examined during a 7 hr allergen exposure. Antigen challenge had no effect on pleural pressure or the distribution of radiolabelled neutrophils, eosinophils or platelets in normal horses. In c...
Burrows GE, Morton RJ, Fales WH.Gram-negative bacterial isolates (635) obtained from routine submissions to the Oklahoma Animal Disease Diagnostic Laboratory during 1983-1987 were tested for antimicrobial susceptibility. Minimal inhibitory concentrations (MICs) were determined for the following antimicrobials using commercially prepared microdilution assay materials: ampicillin, cephalothin, chloramphenicol, erythromycin, gentamicin, kanamycin, oxytetracycline, penicillin G, spectinomycin, sulfachlorpyridazine, sulfadimethoxine, and tylosin. Results for isolates from cattle, dogs, horses, and pigs are presented. In only a fe...
Baker SJ, Gerring EL.Intragastric pH monitoring was investigated in ponies. In cadaver stomachs, close contact with the mucosa led to high pH readings if nonweighted electrodes were used. However, pH recorded by weighted electrodes was markedly less affected by mucosal contact (P < 0.001). The latter were used for subsequent trials. In vivo, high correlations were found between pH recorded by weighted electrodes with or without a wire guard to prevent mucosal contact (correlation, r = 0.866; P < 0.001). Readings from each correlated well with those from simultaneous gastric aspirates (r = 0.774 and r = 0.807...
Dabareiner RM, Snyder JR, Sullins KE, White NA, Gardner IA.Intramural vascular patterns of the jejunum and colon were evaluated during ischemic strangulation obstruction (ISO, 70 minutes) and subsequent reperfusion (60 minutes) in 7 adult anesthetized horses. Microvasculature of experimental and control segments was described by comparison of results from microangiography, light microscopy, and scanning electron microscopy of vascular replicas. Experimental and control segments with isolated vascular arcades were removed either immediately after the experimental period or after 60 minutes of reperfusion. Blood was flushed from the vascular system by u...
Hoffman AM, Viel L, Juniper E, Prescott JF.Respiratory tract infections are prevalent in foals, yet the frequency with which the distal airways are affected in clinical episodes of respiratory tract disease has not been evaluated to our knowledge. The objective of the study was to determine the incidence of distal respiratory tract infection (DRTI) in foals on a sample of Thoroughbred breeding farms (n = 10) in Ontario. In a pilot study, clinical criteria commonly used to select foals for antimicrobial treatment (detection of abnormal lung sounds, plus nasal discharge, cough, fever, tachypnea, and/or lethargy) were found to segregate f...
Hoffman AM, Viel L, Prescott JF, Rosendal S, Thorsen J.Undifferentiated distal respiratory tract disease (nasal discharge, cough, pneumonia) in foals (1 to 8 months old) is a burdensome economic problem on breeding farms; yet, the infective agents associated with these episodes have not been well described. Possible causes of these episodes of illness were investigated by culturing specimens of proximal and distal airways of clinically diseased foals (n = 101), prior to any treatment, for aerobic and anaerobic bacteria and viruses (rhinoviruses, equine arteritis virus, equine herpesvirus subtype 1 [EHV-1], influenza virus, and adenovirus). Pairs o...
Waelchli RO, Känzig M, Gygax A, Corboz L, Rüsch P.A total of 368 uterine swabs were taken from mares in heat (n = 202) and from mares that were not in heat (n = 166). From 72 of the mares, two swabs were taken; one during either seasonal anoestrus or dioestrus, and one during oestrus. Swabs were taken during anoestrus/dioestrus in 94 other mares and during oestrus in the remaining 130 mares. Bacteriological cultures were done aerobically and classified as negative, insignificant or significant. There was a trend for more positive cytological specimens during oestrus than during anoestrus/dioestrus. The proportions of significant cultures were...
Thein P, Darai G, Janssen W, Bergle RD, Strube W, Floss G.From spring 1990 to summer 1991 we investigated 21 horses with clinical symptoms of EHV-infection by means of serological and virological methods including DNA-hybridization to identify the causative agents. The results indicated that, as already reported by us, EHV4 may also cause the paralytic form of the infection. The possibility of double infection with EHV4 and EHV1 cannot be excluded. In 3 out of 21 affected horses we could investigate brain tissue and/or spinal fluid by Dotblot hybridization with EHV1 and EHV4-DNA. The investigated samples of all three horses showed hybridization with ...
Watson TD, Packard CJ, Shepherd J.1. Equine plasma contains lipoproteins corresponding to very low density (VLDL), low density (LDL) and high density lipoproteins (HDL). 2. HDL accounts for approximately 60% of plasma lipoprotein mass and consists of a single population of particles. 3. LDL is heterogeneous comprising three discrete subfractions. 4. Two proteins are found in the region of apolipoprotein (apo) B-100 in VLDL and LDL and a third similar to apoB-48 is in VLDL. 5. Lecithin:cholesterol acyl transferase is active in plasma and hepatic lipase and lipoprotein lipase are evident in post-heparin plasma. 6. There is no si...
Johnson PJ, Lin TL, Jennings DP.Cholesterinic granulomas, commonly found at necropsy in aged horses, may cause neurologic signs by obstructing the interventricular foramina, resulting in hydrocephalus. Diffuse cerebral disease in horses may not always result in rapid progression of clinical signs. Intermittency of neurologic signs may be associated with intermittent increases in CSF pressure.
Oladosu LA, Olayeye OD, Baba SS, Omilabu SA.An outbreak of African horse sickness involving two horse stables in Lagos, Nigeria, was investigated. Inoculation of blood from infected horses into suckling albino mice resulted in isolation of a virus which was identified as African horse sickness virus by the complement fixation test. The clinical, pathological and epizootiological findings (reported elsewhere) were consistent with African horse sickness. Potential threats of the epidemic to international horse trade are briefly highlighted.
Ross MW, Sponseller ML, Gill HE, Moyer W.Articular fracture of the dorsoproximolateral aspect of the third metatarsal bone (MT3) caused an acute onset of lameness in 5 horses; however, 3 of the horses had historical and radiographic or scintigraphic evidence of chronic tarsal and metatarsal disease before fracture. The pathogenesis of dorsoproximolateral fracture of MT3 remains unclear, but the fracture may occur as a result of the formation of abnormal bone in the proximal aspect of MT3. The prognosis for racing in horses with this fracture appears to be guarded.
Kannegieter NJ, Colgan SA.The arthroscopic findings in 104 intercarpal joints in 76 horses were reviewed to determine the incidence and severity of changes in the medial intercarpal ligament. Damage to the intercarpal ligament was observed in 43 joints in 35 horses, ranging from mild fraying of the edges of the ligament to complete disruption of all fibres. This represented an incidence of 41% of joints being affected. In 9 joints examined arthroscopically primarily as a further diagnostic procedure, ligament damage was evident in all cases. In horses undergoing arthroscopic surgery primarily for the treatment of osteo...
Mair TS, Lane JG, Lucke VM.The clinical and post mortem features of 11 cases of lymphosarcoma involving the thoracic cavity are reviewed. The clinical findings included inappetence, weight loss, pectoral oedema, dyspnoea, pleural effusion and distension of the jugular veins. Dysphagia was present in three cases. At post mortem examination lesions were found in the abdomen as well as the chest in eight cases; clinical signs of abdominal disease were present in two cases. The features of nine other similar cases recorded in the literature are reviewed.
Gaughan EM, Gift LJ, DeBowes RM, Frank RK, Veatch JK.An 8-year-old Quarter Horse mare was examined for chronic nasal discharge and obstruction of both nasal passages. A solid mass lesion was identified in the maxillary sinuses, soft palate, nasal and pharyngeal cavities. Palliative surgery was used to debulk the lesion and facilitate nasal airflow. Squamous cell carcinoma was diagnosed from surgical biopsies. Approximately 7-8 weeks after surgery, the mare was observed to be acutely blind. Ophthalmologic examination revealed central origin blindness and active retinitis. The squamous cell carcinoma had reobstructed the nasal passages. Pressure b...
Wiśniewski E, Kuźma K.The normal level of plasma lysozyme of 9 Tarpane-like horses was 0.922pg/ml. This was
calculated from determinations performed 5 times in a period of 14 months. Observations on the
normal plasma level of lysozyme in the horse revealed marked variations in individual animals, as well
as in the whole group and in the mean values calculated for individual horses. The model for the
subsequent studies was an experimental fever evoked by the administration of E. colz LPS in a dose of
0.1 pg/kg body weight. Blood samples from the jugular vein were taken just before LPS injection, and
then for 8...
Cudmore LA, Groenendyk JC, Hodge P, Church S.This case report describes neurological signs associated with a pyogranulomatous lesion within the sacral vertebral canal of a horse. The clinical findings included urinary overflow incontinence and reduced anal, perianal and tail tone. The horse failed to respond to medical management and a guarded prognosis for return to athletic performance initiated the decision for euthanasia.
Genton M, Robert C, Jerbi H, Huet H, Cordonnier N, Vitte-Rossignol A, Perkins JD, Rossignol F.To describe the innervation of the thyrohyoideus (TH) muscle and to confirm our findings with stimulation of first cervical (C1) nerve branches. Methods: Ex vivo phase 1 and clinical phase 2. Methods: Fourteen head and neck specimens and 17 client-owned horses. Methods: In phase 1, the cranial nerve (CN) XII and the C1 nerve were dissected with their branches in 20 dissections were performed on 14 specimens (6 left and right side and 8 only left or right) Anatomy was noted. Samples of nerve bifurcations were collected for histological confirmation of anatomical findings. First cervical nerve b...
Herholz CP, Gerber V, Tschudi P, Straub R, Imhof A, Busato A.To investigate whether volumetric capnography indices could be used to differentiate between horses without recurrent airway obstruction (RAO) and horses with RAO that were in clinical remission or that had clinically apparent RAO. Methods: 70 adult Swiss Warmblood horses (20 used for pleasure riding and 50 used for dressage or show jumping). Methods: Horses were allocated to 4 groups on the basis of history, clinical signs, results of endoscopy, and cytologic findings (group 1, 21 healthy horses; group 2, 22 horses with RAO that were in remission; group 3, 16 horses with mild RAO; group 4, 11...
Naylor JM, Robinson JA, Crichlow EC, Steiss JE.Electromyography (EMG) was used to detect myotonic discharges in Quarter Horse breeding stock and to follow the results of mating horses with hyperkalemic periodic paralysis (HPP). The studies were performed on two brood mare farms. A total of six breeding stock showed myotonic discharges and 15 were nonmyotonic. Myotonic discharges were seen in five of six horses belonging to the blood line previously implicated as being predisposed to HPP. Two of these horses had shown clinical signs of HPP. Only one of 15 breeding horses unrelated to the HPP predisposed blood line showed myotonic discharges...
Gomez DE, Valberg SJ, Magdesian KG, Hanna PE, Lofstedt J.This report describes a case of severe rhabdomyolysis in a pregnant mare associated with histopathologic and biochemical features of both selenium deficiency and acquired multiple acyl-CoA dehydrogenase deficiency (MADD) due to seasonal pasture myopathy (SPM). This case highlights the importance of assessing plasma selenium levels in horses with clinical signs of pasture myopathy as this deficiency may be a contributing or exacerbating factor. Déficience multiple acquise de déshydrogénase acyl-CoA et carence en sélénium marquée causant une rhabdomyolyse grave chez un cheval. Ce rapport d...
Holley DC, Evans JW.Total and ultrafilterable calcium (Ca) and magnesium (Mg) values were determined for Shetland pony stallions, stallions, and pregnant and diestrous mares, using a simple, inexpensive, quick procedure to obtain an ultrafiltrate of serum. There was no significant difference between horses and ponies, between stallions and mares, or between pregnant and nonpregnant mares. The percentage of total serum Ca that was ultrafilterable was 63.4+/-1.7 for horses and 64.8+/-2.2 for ponies. The percentage of total serum Mg that was ultrafilterable was 75.6+/-1.5 for horses and 77.0+/-1.7 for ponies. Total ...
Calisher CH, Maness KS.During the summer and fall of 1971, epizootic and epidemic Venezuelan equine encephalitis was detected in Texas. Isolates of epizootic (IB) and vaccine (TC-83) strains were distinguished by virulence of the former for guinea pigs. Vaccine virus was isolated from 1 to 14 days after vaccination and neutralization tests demonstrated the appearance of antibody about a week after vaccination. Viremia titers of subtype IB in horses ranged from 2.2 to 8.3 log10 suckling mouse intracranial 50% lethal doses per ml. Of 101 equines from which Venezuelan equine encephalitis virus (IB or TC-83) strains wer...
Gray PR, Derksen FJ, Broadstone RV, Robinson NE, Johnson HG, Olson NC.Airway obstruction and hyperreactivity are characteristics of human asthma and of "heaves," a naturally occurring respiratory disorder of horses and ponies. We measured pulmonary function and plasma immunoreactive 15-hydroxyeicosatetraenoic acid (i15-HETE) concentrations in simultaneously collected carotid artery and right ventricle blood samples in five affected ponies and their age- and gender-matched control ponies. Measurements and sampling were performed before (Period A), during (Period B), and following recovery from (Period C) acute airway obstruction precipitated by housing ponies in ...
Javed R, Taku AK, Sharma RK, Badroo GA.The aim was to determine the occurrence of in equines and their environment in Jammu (R.S. Pura, Katra), molecular characterization and to determine the antibiotic resistance pattern of . Methods: A total of 96 nasopharyngeal swab samples were collected from equines. The organism was isolated on Columbia nalidixic acid agar containing 5% sheep blood as well as on sheep blood agar and was later confirmed by cultural characteristics and biochemical tests. Molecular detection of isolates was done by gene amplification followed by virulence associated protein A () gene amplification. Antibiogra...