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.
Baker SJ, Gerring EL.Impedance epigastrography was used to measure gastric emptying rates on two occasions in each of three foals. After smoothing of the raw data, emptying of water appeared to obey an exponential model. The mean emptying rate constant (SEM) was 0.171 +/- 0.038 min-1 (mean emptying half time 4.9 +/- 1.0 min).
Edington N, Welch HM, Griffiths L.Equid herpesviruses 1 or 4 (EHV-1 or -4) were isolated by cocultivation from 60% of 40 horses examined at slaughter. The lymph nodes draining the respiratory tract were the most common source of virus. EHV-1 or EHV-4 was never isolated from the trigeminal ganglia (SLG). The polymerase chain reaction (PCR) detected virus in 87.5% of bronchial lymph nodes and a similar level in the trigeminal ganglia that were examined. By both assays approximately one third of the positive animals harboured both viruses. Equid herpesvirus 2 (EHV-2) was isolated from all but one of the horses and from > 75% o...
St-Laurent G, Morin G, Archambault D.A reverse transcription (RT)-PCR assay was developed for the detection of equine arteritis virus (EAV) in cell culture supernatant and in horse semen. Four different sets of oligonucleotide primers complementary to sequences located in the 3' end of the polymerase gene (open reading frame [ORF] 1b) and to sequences representing the entire ORFs 3, 4, and 7, which encode for nonstructural (ORFs 3 and 4) or viral nucleocapsid (ORF 7) proteins, were compared for their abilities to amplify the targeted EAV sequences by the RT-PCR procedure. The sensitivities of the RT-PCR for amplification of EAV s...
LeBlanc MM, Neuwirth L, Asbury AC, Tran T, Mauragis D, Klapstein E.The percentage of Technetium 99m-albumin colloid (99mTc-microAA), a radiocolloid, cleared from the uterine lumen within 4 h of intrauterine infusion, was measured in 15 mares during 2 consecutive cycles, on Day 3 of oestrus and 48 h after ovulation. Four nulliparous (Group 1) and 4 multiparous (Group 2) mares were classified as resistant and the remaining 7 multiparous mares were classified as susceptible (Group 3) to endometritis. Mares in Groups 1 and 2 cleared more 99mTc-microAA from their uteri than did mares in Group 3 during oestrus (P < 0.01) and 48 h after ovulation (P 50% of the c...
MacAllister CG, Lowrey F, Stebbins M, Newman MS, Young B.The ponies were apparently healthy and 6-20 months of age. In Study 1, gastric lesions were created by transendoscopic electrocautery in the non-glandular gastric mucosa, adjacent to the margo plicatus in 9 ponies which were then treated with water, 12 mg cimetidine HCl/kg bwt or 18 mg cimetidine HCl/kg bwt per os every 12 h for 35 days. In Study 2, gastric lesions were similarly induced in 9 ponies in the non-glandular mucosa and also in the glandular mucosa just below the non-glandular lesion on the greater curvature of the stomach. The ponies were treated with water, 8 mg cimetidine/kg bwt ...
Stanley S, Wood T, Goodman JP, Henry PA, Woods WE, Chang SL, Tai HH, Watt D, Kwiatkowski S, Blake JW.We have raised antibodies and developed one-step enzyme-linked immunosorbent assays (ELISA) for the diuretics ethacrynic acid and bumetanide as part of a panel of pre- and post-race tests for high potency drugs in racing horses. These ELISA tests are rapid (completed within one hour), sensitive, and can be read by eye. The ELISA detects ethacrynic acid at a drug concentration for half-maximal inhibition (I-50) of about 2.5 ng/mL for the parent drug. After dosing horses intravenously with 5 mg ethacrynic acid per horse, the parent drug or its metabolites are detectable in urine for at least 8 h...
Jean D, Lavoie JP, Nunez L, Lagacé A, Laverty S.A 6-year-old Thoroughbred mare had a 7-cm ulcerated mass on the cranial aspect of the left cervical area. Ultrasonography revealed the mass to be < 1 cm thick and composed of small lobules that were filled by material hypoechoic to the surrounding muscle tissues. Fine-needle aspiration of the mass yielded blood, and cytologic examination revealed a few epithelial cells with neoplastic changes. Thoracic radiography revealed an interstitial pattern with several disseminated nodules. A diagnosis of cutaneous hemangiosarcoma with pulmonary metastases was made. The diagnosis was confirmed at necrop...
Grund CH, Lechman ER, Issel CJ, Montelaro RC, Rushlow KE.In this study we used immune sera from equine infectious anaemia virus (EIAV)-infected horses which uniquely display broad reactivity with different lentivirus capsid proteins (CA) to characterize the cross-reactive determinants of lentivirus CA proteins. In particular, the role of the major homology region (MHR) of lentivirus CA proteins in this serological cross-reactivity was evaluated using both equine immune serum and murine monoclonal antibodies (MAbs) directed against the MHR segment of different lentiviruses. The results of our studies indicate that about 80% of sera from long-term exp...
Krasnianskiĭ VP, Mikhaĭlov VV, Borisevich IV, Gradoboev VN, Evseev AA, Pshenichnov VA.Immunization of horses with Ebola virus resulted in the production of specific virus-neutralizing antibody with maximum titres at 28-42 days. Repeated cycles of immunization led to a rise in antibody titres to 1:4096.
Hamlen HJ, Timoney JF, Bell RJ.A 2-phase study was performed to characterize the effects of Streptococcus equi infection in unexposed and previously exposed foals. In phase I, 22 weanling foals involved in a naturally occurring S equi epizootic were studied, along with a comparison group of 11 unexposed foals, matched for age, sex, and breed. Six months later (phase II), an epizootic was experimentally induced in previously exposed and unexposed foals from phase I. The prevalence and duration of clinical signs, the relative risk of developing disease, bacteriologic culture results, hematologic responses, and mucosal and ser...
Ducharme NG, Hackett RP, Ainsworth DM, Erb HN, Shannon KJ.Repeatability of measurements of peak and mean tracheal and pharyngeal pressures in exercising horses was determined. Five athletically fit horses were subjected to repeated (n = 5) standardized exercise trials. Static pressures in the trachea, nasopharynx, and mask were determined. At least 96% of all mean pressure measurements were within 5 cm of H2O of the mean value for any horse. Peak pressure measurements were less repeatable, but at least 96% of all measurements were within 10 cm of H2O of the mean peak measurements for any horse. In 10 horses galloping at 14 m/s, the 95% confidence int...
Pemberton AD, John HA, Ricketts SW, Rossdale PD, Scott AM.Failure to inhibit proteinases can lead to excessive tissue damage. The possibility that the severity of endometritis in Thoroughbred mares correlates with the haplotypes of plasma alpha 1-proteinase inhibitor (alpha 1-PI) expressed was investigated in two groups of mares. In mares with pyometritis before treatment, the frequency of the N haplotype, which is already high in the Thoroughbred population, was significantly increased when compared with that in a large published population. In mares with acute endometritis which persisted after treatment followed by sexual rest, the absence of S an...
Williams DM, Smith BJ, Donahue JM, Poonacha KB.Blood and urine samples from horses on 3 central Kentucky horse farms with prior histories of leptospiral abortions were analysed. Blood samples were obtained from all available horses on each farm and tested for antibodies to 6 leptospira serovars. Urine samples were collected from non-gravid mares with serum antibody titres > or = 1:800 and examined for leptospires by dark-field microscopy, fluorescent antibody testing and culture. Adult horses had the greatest serological evidence of exposure to leptospira, followed by yearlings, then foals. Of horses with anti-leptospiral antibodies, 76...
Turell MJ, Beaman JR, Neely GW.The vector competence of Aedes taeniorhynchus (Wiedemann) and four strains of Aedes albopictus (Skuse) was assessed for eastern equine encephalitis (EEE) virus isolated from Ae. albopictus collected in Polk County, Florida. Both species became infected with and transmitted EEE virus by bite after feeding on 1-d-old chicks that had been inoculated with EEE virus (viremia = 10(10.1) plaque-forming units [PFU] per ml of blood). However, when fed on an older chick with a lower viremia (viremia = 10(6.1) PFU per ml of blood), Ae. albopictus was significantly more susceptible to infection (90%, n = ...
Stone-Marschat M, Carville A, Skowronek A, Laegreid WW.Reverse transcription-PCR (RT-PCR) was used to detect African horse sickness virus (AHSV). A single primer pair which amplified a 423-bp fragment of the S8 gene which encodes the NS2 protein of AHSV was identified. Amplification of this fragment from all nine serotypes of AHSV was achieved with these primers. Between 10(1) and 10(2) copies of AHSV genomic double-stranded RNA could be detected by RT-PCR followed by agarose gel electrophoresis and ethidium bromide staining. Application of RT-PCR to blood samples from AHSV-infected horses resulted in earlier detection of viremia than virus isolat...
Rojas G, Jiménez JM, Gutiérrez JM.A simple methodology for hyperimmune horse plasma fractionation, based on caprylic acid precipitation, is described. Optimal conditions for fractionation were studied; the method gives best results when concentrated caprylic acid was added to plasma, whose pH had been adjusted to 5.8, until a final caprylic acid concentration of 5% was reached. The mixture was vigorously stirred during caprylic acid addition and then for 60 min; afterwards the mixture was filtered. Non-immunoglobulin proteins precipitated in these conditions, whereas a highly enriched immunoglobulin preparation was obtained in...
Valberg SJ, Carlson GP, Cardinet GH, Birks EK, Jones JH, Chomyn A, DiMauro S.Although exertional myopathies are commonly recognized in horses, specific etiologies have not been identified. This is the first report in the horse of a deficiency of Complex I respiratory chain enzyme associated with profound exercise intolerance. Physical examination, routine blood tests, endoscopy, and ultrasonograms of the heart and iliac arteries were unremarkable. With slow, incremental exercise (speeds 1.5-7 m/s), the Arabian mare showed a marked lactic acidosis, increased mixed venous PVO2, and little change in oxygen consumption. Muscle biopsies contained large accumulations of mito...
Reid SW, Gettinby G, Fowler JN, Ikin P.An epidemiological study of equine sarcoid in a population of 4126 donkeys showed that the peak incidence of the disease was 15.2 cases per 100 animal-years and occurred in animals in their fourth year of life. The crude incidence of the disease was 0.6 cases per 100 animal-years. The disease occurred most frequently in younger, male animals during their first five years in the population. The lesions were observed most commonly in the paragenital region. Pre-entry quarantine procedures did not appear to play a significant role in the spread of the disease but there was an indication that clos...
Gillis JP, Taylor TS, Puckett MJ.A 5-year-old Arabian stallion was treated medically 6 days for proximal enteritis. On the sixth day, exploratory celiotomy verified the diagnosis and ruled out other intraluminal and extraluminal gastrointestinal tract obstructions. A gastrojejunostomy was performed. The horse had trouble maintaining and gaining weight in the first year after surgery, but 8 years after surgery, the owner reported that the horse was doing well.
Dybdal NO, Hargreaves KM, Madigan JE, Gribble DH, Kennedy PC, Stabenfeldt GH.Pituitary pars intermedia dysfunction is a slowly progressive disorder that afflicts most breeds of horses. Because it shares features with human Cushing disease, it has been referred to as equine Cushing disease. A variety of tests of pituitary-adrenocortical function were performed on horses with evidence of pituitary pars intermediate dysfunction, and results were compared with those in healthy control horses. Diurnal variations in plasma cortisol concentration were not statistically different between control horses and those with pituitary pars intermedia dysfunction. An ACTH stimulation (...
Maddison JE.Fifty-nine reports of suspected adverse drug reactions (ADRs) were received by the Adverse Drug Reaction Subcommittee of the Australian Veterinary Association from April 1992-March 1993 inclusive. The number of reports received/number of animals involved per species was: dogs (30/43); cats (11/14); horses (8/10); cattle (9/30); ferret (1/1). Of these, 37 (63%) were classified as definite ADRs and 12 (20%) as probable ADRs. In 10 (17%) reports an ADR could not be substantiated or there was insufficient information available to make a decision. Twenty-three reports involved apparent hypersensiti...
Cothran EG, Long YG.A new D blood group phenogroup consisting of the specificities adeo was observed in a stallion family of Caspian ponies from Iran. An additional six undescribed genetic variants were seen in a total of 82 Iranian horses. This result suggests extensive new genetic variation may be present in domestic horses from geographic regions that have not yet received scientific attention.
De Bosschere H, Simoens P, Ducatelle R.A three-day-old foal died from intestinal strangulation due to a remnant of vitelline vein which extended between the umbilicus and the portal vein. The strangulating vein was identified on the basis of its morphological and histological structure. This finding, which is the first reported case of a persistent vitelline vein in a horse, is discussed in relation to the normal development and involution of the vitelline circulation.
MacDonald MH, Richardson DW, Morse CC.A 23-year-old Thoroughbred stallion was admitted to the hospital for treatment of acute esophageal obstruction. Clinical examination and contrast radiography confirmed the presence of an esophageal obstruction. The horse was euthanatized, and examination revealed a bolus of feed material occluding the esophageal lumen 6 cm caudal to the thoracic inlet, with underlying necrosis of the esophageal mucosa. A large pulsion diverticulum was identified in the caudocervical portion of the esophagus. Apparently, the phytobezoar was formed within the esophageal diverticulum and subsequently became dislo...
Kaye BM, Elliott CR, Jalim SL.Snail bait poisoning is rare in horses. Cases have been reported, but clinical signs and subsequent prognostic indicators have been poorly documented and must be extrapolated from cases in companion animals. We describe in detail the poisoning of a horse that consumed a lethal dose of the carbamate, methiocarb. There are currently no guidelines for treating equine methiocarb toxicoses, but the principles of management are based on supportive therapy.
Witarski W, Kij B, Nowak A, Bugno-Poniewierska M.A hucul mare with reproductive abnormalities was examined during karyotype analysis. The karyotype was analysed based on evaluation of 860 metaphase plates in chromosome preparations. The use of fluorescence in situ hybridization (FISH) with an X chromosome painting probe showed premature X chromosome separation in 9.5% cases of examined chromosome spreads. In this report, we present the first identify premature centromere division (PCD) as a possible cause of abnormal X chromosome morphology in horses and as a probable cause of reproductive difficulties.
Kumar P, Timoney JF.The microstructural and ultrastructural features of the equine lingual tonsil were studied in five young horses. Located at the root of the tongue it presented an irregular surface with rounded elevations, numerous folds and crypts. Stratified squamous non-keratinized epithelium lining its outer surface was modified by heavy infiltration of lymphoid cells to form reticular epithelium within the crypt. The latter implies a role in initiating and maintaining immune responses to incoming infectious agents and antigens. Lamellated structures resembling Hassall's corpuscle were observed towards the...
Barton CK, Sandow CB, Rodgerson DH.This manuscript describes exostosis lesions originating from the caudal aspect of the proximal tibia identified in three Thoroughbred yearlings as part of the routine review of presale radiographic images. These lesions are hypothesized to be osteochondromas. The identification of bony exostoses on the proximal tibia has not been reported before in current literature. As they have not been described, the future effect on performance or soundness is unknown. Although these cases were not lame at the time of detection, the future growth of the lesion and its impact on surrounding soft tissues is...
Easley KJ, Osborne J, Thorpe PE.Many factors should be considered before one makes a decision to perform surgery, and it is the practitioner's responsibility to make certain the client makes an informed decision. This article considers the various factors of importance in the decision-making process.
Forsyth J, Halliwell RE, Harrand R.Identification of environmental allergens in horses with allergic disease facilitates allergen avoidance and targeted immunotherapy. Objective: To evaluate allergenic co-reactivity between 44 environmental allergens. Methods: Horses with suspected allergic disease (n = 344) whose sera were submitted for environmental allergen testing. Methods: Allergen-specific IgE serological assays were performed using 44 allergens divided into six taxonomically related groups: house dust/storage mites, moulds, insects, grass, tree and weed pollens. Using pairwise comparisons, odds ratios (ORs) were calcul...
Feige K, Eser MW, Geissbühler U, Balestra E, Metzler K.Hirsutism was the most often observed symptom in horses with a pituitary gland tumor and was present in all 13 examined horses. Other symptoms were atrophy of muscles (n = 10), hyperhidrosis (n = 8), polyuria/polydipsia (n = 5), bulging or supraorbital fat (n = 3), polyphagia (n = 2), apathy (n = 2) and seizures (n = 2). Laminitis was the most frequently observed concurrent disease (n = 8). Hyperglycaemia (mean, 9.9 +/- 3.71 mmol/l) in 13 horses and glucosuria (median, 55 [range, 2-55] mmol/l) in 7 horses were the most important laboratory results. The dexamethasone suppression test was positi...
Rijkenhuizen AB, Németh F.The clinical signs, the radiographic appearance, and the treatment of two cases of fracture of the accessory carpal bone are described. The fractures were in the vertical plane. Surgical intervention consisted out of fixation of the fracture with two lag screws. Follow-up information revealed that one horse became sound and returned to complete athletic activity whereas the other horse remained lame. A brief literature review is given and the surgical treatment and the complications are discussed.
Barth AD, Barber SM, McKenzie NT.A two month old Thoroughbred filly was presented with signs of depression, grinding of the teeth, frothing of the mouth and abdominal pain. These signs had persisted for two weeks despite treatment with mineral oil, dioctyl sodium sulfosuccinate, meperidine and antibiotics. A variety of diagnostic tests were done, the only abnormal finding was a stress leukon. On exploratory laparotomy the stomach was dilated with fluid and gas and the pyloric canal was constricted. Pyloroplasty resulted in correction of the condition. The etiological possibilities are discussed. This is believed to be the fir...
Odelros E, Kendall A, Wulcan S, Bergvall K.Otitis externa is rare in horses and the condition is poorly described in the literature. Objective: To describe clinical signs, treatment regimens and prognosis of otitis externa in horses. Methods: Eight horses diagnosed with otitis externa during 2011-2018. Methods: Retrospective review of medical records and follow-up contact with owners. Results: Common clinical signs seen in affected horses were pruritus, ear discharge and ear droop of affected ears. The most common cytological findings were neutrophils, bacteria and yeast. All horses responded well to treatment; two horses were reported...
Coultous RM, Raftery AG, Shiels BR, Sutton DGM, Weir W.Sarcocystis fayeri is a canine protozoan parasite with an equine intermediate host. Historically classified as an incidental pathogen, recent literature has described the toxic effects of Sarcocystis fayeri in human food poisoning, and highlighted potential involvement in equine neuromuscular disease. Until now, horses were believed to be the exclusive intermediate host. This study reports the first molecular confirmation of S. fayeri in a donkey, and gives rise to the consideration of donkeys being a potential reservoir for the parasite. This finding is of particular importance in understandi...