Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
Knight DA, Weisbrode SE, Schmall LM, Reed SM, Gabel AA, Bramlage LR, Tyznik WI.The potential role of dietary copper in the development of cartilage defects in foals was investigated. Twenty-one mares were fed rations containing 13 ppm copper (CuC, control) or 32 ppm copper (CuS, supplemented) during the last three to six months of gestation and first three months of lactation. Their foals were fed pelleted concentrate containing 15 or 55 ppm Cu and were destroyed at 90 (5 CuC and 5 CuS foals) or 180 (6 CuC and 5 CuS foals) days. Focal cartilage lesions were found at multiple sites on necropsy. In foals killed at 90 days, there were over twice (9 versus 4) as many lesions...
Brewer BD, Clement SF, Lotz WS, Gronwall R.The glomerular filtration rate (GFR) was estimated in eight full-term neonatal foals by the single injection inulin plasma clearance method at two days of age, the continuous infusion plasma and urinary clearance methods at three days of age, and the 12-hour endogenous creatinine clearance method at four days of age. The effective renal plasma flow (ERPF) was estimated simultaneously by the single injection para-aminohippuric acid (PAH) plasma clearance method in the eight two-day old foals and the continuous PAH infusion plasma and urinary clearance method in the eight three-day old foals. Th...
Monteiro-Riviere NA, Bristol DG, Manning TO, Rogers RA, Riviere JE.Studies in dermatology, cutaneous pharmacology, and toxicology utilize skin from different animal species and body sites. However, regional differences exist in topical chemical percutaneous absorption studies in man and in animal. The objective of this study was to compare epidermal thickness and number of cell layers across species and body sites using both formalin-fixed paraffin and frozen sections. Cutaneous blood flow determined by laser Doppler velocimetry (LDV) was compared to histologic data. Six animals of each of the following species were used: monkeys, pigs, dogs, cats, cows, hors...
Ekfalck A, Rodriguez-Martinez H, Obel N.Explants from the matrix of the stratum medium of the wall of the equine and bovine hoof each were cultured on a microporous membrane, using a standard culture medium. After incubation at 37 C, the outgrowth was a mixture of keratinocytes and fibroblasts, with predominance of the latter. After incubation at 34 C, the keratinocytes dominated, covering the lateral surfaces of the explant as well as the basal surface. Lateral outgrowth of keratinocytes was observed at the borderline of the original epidermis and at the borderline of the explant's contact with the membrane. Epithelial outgrowth fr...
Vörös K, Holmes JR, Gibbs C.This study was designed to evaluate the accuracy of two-dimensional echocardiography (2DE) in determining the left ventricular volume (LVV) of the horse in vitro. After examining the shape of the left ventricular silicon rubber casts of four equine hearts, two modified Simpson's rule methods (Model A and Model B) as combinations of conical shapes and one biplane area-length method as a single cone (Model C) were chosen for volume calculations. One long axis and three short axis planes were used for linear and area 2DE measurements, respectively. The ventricular length (L) was calculated from t...
Frank M, Weckman TJ, Wood T, Woods WE, Tai CL, Chang SL, Ewing A, Blake JW, Tobin T.Hordenine is an alkaloid occurring naturally in grains, sprouting barley, and certain grasses. It is occasionally found in post race urine samples, and therefore we investigated its pharmacological actions in the horse. Hordenine (2.0 mg/kg bodyweight [bwt]) was administered by rapid intravenous (iv) injection to 10 horses. Typically, dosed horses showed a flehmen response and defecated within 60 secs. All horses showed substantial respiratory distress. Respiratory rates increased about 250 per cent and heart rates were approximately double that of resting values. All animals broke out in a sw...
Heath SE, Bell RJ, Clark EG, Haines DM.Clinical signs of generalized granulomatous disease in a horse included depression, generalized lymphadenopathy, scaly skin, and dependent edema. Diagnosis was confirmed histopathologically by diffuse granulomas in more than one organ system (lymph nodes and skin), and by ruling out etiologic agents. Response to treatment with corticosteroids was favorable. The clinical features and response to treatment in this horse were different from classic textbook descriptions of equine generalized granulomatous disease. Equine granulomatous disease appears to be comparable to human sarcoidosis. To avoi...
Cornick JL, Seahorn TL.During a 3 1/2-year period, cardiac arrhythmias were identified in 6 of 67 horses diagnosed with duodenitis/proximal jejunitis (DPJ). Arrhythmias were detected by auscultation of irregular cardiac rhythm and subsequently were characterized by electrocardiographic evaluation. Arrhythmias included frequent second-degree atrioventricular block, ventricular ectopic depolarizations, and atrioventricular conduction disturbance. In 4 horses, arrhythmias resolved with recovery from the primary problem. One horse died suddenly 66 hours after admission, and another was euthanatized at 72 hours after adm...
Pereira A, Braekman JC, Dumont JE, Boeynaems JM.The incorporation of iodide into proteins (PBI) and lipids (LBI) of horse thyroid slices was measured in various conditions. Their dependency on the concentration of extracellular iodide was strikingly different. For PBI the relationship was biphasic with a decrease above 10 microM, likely to correspond to the Wolff-Chaikoff effect. On the contrary, LBI increased as a function of iodide concentration up to 100 microM. Methimazole (MMI) inhibited the incorporation of iodide into both LBI and PBI, but higher concentrations of MMI were required to depress LBI as compared to PBI. The inhibition of...
Verma RD, Sharma JK, Venkateswaran KS, Batra HV.A dot enzyme-linked immunosorbent assay (dot ELISA) was developed for diagnosis of glanders in equines. The test was based on the detection of IgG antibodies to Pseudomonas mallei antigens bound to nitrocellulose coated on plastic strips (dipsticks), the reaction being amplified by an avidin-biotin system with biotinylated anti-horse IgG and horseradish peroxidase-avidin D. Sera from 810 normal, six naturally infected and 48 sensitized equines were tested by this assay, and results were compared with complement fixation, indirect haemagglutination and counter-immunoelectrophoresis tests. Dot E...
Little CB, Hilbert BJ, Wickstrom S, Hedlund BE.An alcian blue precipitation method for quantifying the hyaluronic acid (HA) and sulphated glycosaminoglycan concentration (SGAG) in solutions containing both compounds was assessed. The assay was found to be rapid and reliable in solutions containing 0 to 200 mg of HA/dl and 50 to 1,000 micrograms of SGAG/dl, and was not affected by the presence of protein, hemoglobin, or methemoglobin in concentrations normally found in synovial fluid. The HA and SGAG concentrations in intercarpal synovial fluid from 13 clinically normal and 11 arthritic horses were evaluated. A relationship was not found be...
Rabb MH, Thompson DL, Barry BE, Colborn DR, Hehnke KE, Garza F.Six pony geldings were actively immunized against GnRH conjugated to bovine serum albumin (BSA) to study 1) the relative dependency of LH and FSH storage, secretion and response to GnRH analog on GnRH bioavailability and 2) the effects of reduced GnRH bioavailability on GnRH storage in the hypothalamus. Five geldings were immunized against BSA. Geldings were immunized in December and 4, 8, 14, 20, 26 and 32 wk later. Ponies immunized against GnRH had increased (P less than .01) GnRH binding in plasma within 6 wk. By June, plasma concentrations of LH and FSH in ponies immunized against GnRH had...
Anderson WI, Scott DW, Crameri FM.Two rare equine cutaneous neoplasms, an apocrine gland adenocarcinoma and a carcinosarcoma were diagnosed in a 17-year-old pony and a 14-year-old mare, respectively. The apocrine gland adenocarcinoma was present on the prepuce. Histologically, papillary projections of low cuboidal to columnar epithelial cells were generally well differentiated, and surrounded dilated acini. Stromal invasion was present, but vascular and lymphatic invasion was not seen. The carcinosarcoma was present in the right flank of the mare. Two discrete cell populations were characterized histologically. One portion of ...
Cummings JF, de Lahunta A, George C, Fuhrer L, Valentine BA, Cooper BJ, Summers BA, Huxtable CR, Mohammed HO.A spontaneous motor neuron disease or neuronopathy was identified in 10 horses from the northeastern United States. Signs of generalized weakness, muscle fasciculations, muscle atrophy and weight loss progressed over 1 to several months in young and old horses of various breeds. Pathologic studies revealed that degeneration and loss of motor neurons in the spinal cord and brain stem resulted in axonal degeneration in the ventral roots and peripheral and cranial nerves and denervation atrophy of skeletal muscle. Many spinal neurons were swollen, chromatolytic and contained neurofilamentous accu...
Martinuk SD, Bristol F, Murphy BD.Breeding trials were designed to determine the influence of the mare on serum concentrations of equine chorionic gonadotropin (eCG) from Day 39 to Day 104 of gestation. Sires were ranked according to mean eCG concentrations found in the groups of randomly selected mares to which they were mated in 1983. Mares were ranked according to their mean eCG concentrations on Days 55, 71 and 85 of gestation (Day 0 = mating), in 1983 and 1985. In the 1986 breeding season, mares that had pregnancies characterized by high eCG levels were mated to sires previously associated with low eCG concentration pregn...
Robinson JA, Naylor JM, Crichlow EC.The use of electromyography (EMG) as a diagnostic aid for equine hyperkalemic periodic paresis (EHPP) was investigated in seven affected and seven control horses. Affected horses were confirmed positive for EHPP either by elevated serum potassium concentration with clinical signs of myotonia, or by inducing hyperkalemia and clinical signs using oral potassium chloride challenge. All horses were asymptomatic at the time EMG was performed, using bipolar fine wire needle electrodes. The myopotentials were recorded on magnetic tape and displayed on paper charts for analysis. Insertional and restin...
Houghton E, Dumasia MC, Teale P, Smith SJ, Cox J, Marshall D, Gower DB.Stable isotope gas chromatography/mass spectrometry has been used successfully in the elucidation of structures of urinary steroid metabolites in the horse and in the identification of metabolites isolated from in vivo perfusion and in vitro incubation studies using equine tissue preparations. Deuterium-labeled steroids, testosterone, dehydroepiandrosterone, and 5-androstene-3 beta,17 beta-diol have been synthesized by base-catalyzed isotope exchange methods and the products characterized by gas chromatography/mass spectrometry. [16,16(-2)H2]Dehydroepiandrosterone (plus radiolabeled dehydroepi...
Bowling AT, Millon LV.The phenotypic effects in a yearling Arab filly of a newly described equine autosomal trisomy syndrome for chromosome 30 (65,XX,+30) consisted of small size and severe angular deviation of front legs accompanied by mild polydactyly, but no mental dullness. This case was associated with advanced maternal age. Additional banding studies of a second trisomy case confirmed the assignment to chromosome 26 (64,XX,-26,+t(26q26q)) and evidence of her fertility was presented.
Ascenzi P, Coletta M, Desideri A, Polizio F, Condò SG, Giardina B.The effect of inositol hexakisphosphate (IHP) on the spectroscopic (EPR and absorbance) properties of the nitric oxide derivative of ferrous horse and bovine hemoglobin (Hb) has been investigated. In the absence of IHP, the nitric oxide derivative of ferrous horse Hb shows spectroscopic properties similar to those of the corresponding derivative of ferrous human Hb that are generally taken as typical of the high affinity state of tetrametric hemoproteins. Similar to human Hb, the addition of IHP to the nitric oxide derivative of ferrous horse Hb induces a transition toward a species characteri...
Grauerholz H, Jaeschke G.After the onset of training ("breaking") in young standardbred horses within continuing investigations changes of vectors in the QRS-complex were considered. These changes accomplished in two stages. Mainly within the first three months of training the vector R (VR) in limb leads changed to the left and to caudal and dorsal. In a second interval between five and seven months after breaking the vector S (VS) changed to cranial. As main cause the different character of training in both phases is discussed. Additional indicators of age- or development-related causes were not found.
Hyland JH, Langsford DA.Foetal death was induced in 10 Standardbred mares at day 45 of gestation by injecting 20 to 45 ml of hypertonic (24% W/V) saline into the conceptus at surgery. Ten mares underwent sham treatment and acted as controls. Blood and urine samples were collected every other day between days 30 and 45 post ovulation and at 0, 3 and 6 h relative to the infusion of saline in the treated mares, or sham treatment in control mares. Blood and urine samples were then collected daily between days 46 and 55 post ovulation. Urine oestrone sulphate (E1S) concentrations, measured by radioimmunoassay, increased b...
Greiner EC, Fadok VA, Rabin EB.Nine species of Culicoides were aspirated from horses in Florida during the second phase of a study of equine Culicoides hypersensitivity (CHS). Approximately 90% of the 2933 midges were Culicoides insignis Lutz, 4% were C.stellifer (Coquillett), 3% were C.niger Root and Hoffman, 2% were C.alachua Jamnback and Wirth and the remaining 1% included C.venustus Hoffman, C.scanloni Wirth and Hubert, C.lahillei Iches (= C.debilipalpis Lutz), C.pusillus Lutz, and C.edeni Wirth and Blanton. Culicoides were sampled on seven farms located throughout Florida. The location and seasonality of lesion develop...
Dubey JP, Porterfield ML.Tachyzoites of Neospora caninum were found in sections of lung of an equine fetus aborted 2 mo before term. Individual tachyzoites were approximately 3-5 x 2-3 microns, divided by endodyogeny, and stained positively with anti-N. caninum serum but not with anti-Toxoplasma gondii serum. Toxoplasma gondii antibody was not found in the mare's serum. This is the first report of N. caninum in a horse and indicates that N. caninum can be transmitted transplacentally in equids.
Winder NC, von Fellenberg R.In lungs from 22 horses, the number and type of mast cells in histologically normal specimens were compared with those in specimens with various histological lesions. Tissues fixed in Carnoy's solution were superior to those fixed in formalin for the identification of mast cells. Fixation of lung specimens from eight horses in Carnoy's solution and formalin allowed the identification of two subpopulations of mast cells: formalin-sensitive, which predominated and formalin-resistant. Specimens with mild chronic tracheitis and mild and moderate chronic bronchitis generally had slight increases in...
Minamijima Y, Niwa H, Uchida E, Yamamoto K.In the past decade, mass spectrometry has become an important technology for protein identification. Recent developments in mass spectrometry allow a large number of identifications in samples; therefore, mass-spectrometry-based techniques have been applied to the discovery of biomarkers. Here, we conducted a proteomic study to compare the proteomes in sera between healthy Thoroughbreds and Thoroughbreds with respiratory disease associated with transport (RDT). We found that four proteins, apolipoprotein F, lipopolysaccharide binding protein, lysozyme and protein S100-A8, were upregulated, whi...
Stern JA, Doreste YR, Barnett S, Lahmers SM, Baumwart RD, Seino KK, Bonagura JD.Sustained narrow-QRS tachycardia of three months duration and left ventricular systolic dysfunction were identified in a fifteen-year-old Quarter Horse. No underlying cause for the tachyarrhythmia was found and no predisposing structural cardiac lesions were evident by echocardiography. Intravenous diltiazem and lidocaine were administered without achieving successful conversion of the arrhythmia. Oral quinidine therapy converted the tachyarrhythmia to sinus rhythm. Ventricular systolic dysfunction and chamber dilatation subsequently resolved. As with other species, echocardiographic features ...
Van Hoogmoed LM, Snyder JR, Harmon FA.To evaluate the effect of 2 cyclooxygenase (COX)-2 inhibitors on contractile activity of the circular smooth muscle layer of the equine dorsal and ventral colon. Methods: Samples of the dorsal and ventral colon obtained from 10 healthy horses. Methods: Full-thickness tissue samples were collected from the dorsal colon in the area of the diaphragmatic flexure and the ventral colon in the area of the sternal flexure. Samples were cut into strips oriented along the fibers of the circular muscle layer and mounted in a tissue bath system for determination of contractile strength. Incremental amount...
Houghton E.The methylated xanthines caffeine and/or theobromine are commonly encountered in drug-positive samples from racehorses and their metabolism and excretion in the horse and their analysis in urinary extracts has been of particular interest in this laboratory. Due to their polar nature the dimethylxanthines theobromine, theophylline and paraxanthine give unsatisfactory gas chromatographic performance and require derivatization prior to analysis by gas chromatography mass spectrometry. The present paper describes a simple deuteromethylation procedure to render the compounds amenable to analysis by...
Careddu GM, Evangelisti MA, Columbano N, Masala G, Manunta ML, Passino ES.Progressive ethmoid hematoma is frequently reported among the pathologies of the upper airways in horses. While several hypotheses have been proposed such as repeated trauma, inflammatory processes and/or chronic infections, congenital phenomena, complication of hemangiomas, and neoplastic processes, the aetiology of this condition is yet unknown. Clinical symptoms are non-specific and includes haemorrhagic nasal discharge, respiratory noise not related to physical exercise and, in most severe cases, phenomena of coughing. The purpose of this case report is to contribute to a correct diagnosti...
Brown AE, Hansen PJ, Asbury AC.Uterine flushings collected from mares before and after bacterial-induced inflammation were assayed for ability to opsonize Streptococcus zooepidemicus for phagocytosis by polymorphonuclear leukocytes. Opsonization was measured as the peak phagocytic rate of bacteria preincubated with uterine flushings relative to the peak phagocytic rate of unopsonized bacteria. Flushings from four mares with noninfected uteri were unable to opsonize bacteria regardless of whether uteri were flushed at estrus or on day 10 postovulation. In a second experiment, 7 X 10(9) live S. zooepidemicus were inoculated i...
Içli S, Soleimani M, Oldenhof H, Sieme H, Wriggers P, Wolkers WF.Cryopreservation can be used to store equine oocytes for extended periods so that they can be used in artificial reproduction technologies at a desired time point. It requires use of cryoprotective agents (CPAs) to protect the oocytes against freezing injury. The intracellular introduction of CPAs, however, may cause irreversible osmotic damage. The response of cells exposed to CPA solutions is governed by the permeability of the cellular membrane towards water and the CPAs. In this study, a mathematical mass transport model describing the permeation of water and CPAs across an oocyte membrane...
You Y, Guan F, D'Ippolito R, Li X, Soma LR, Robinson MA.A hydrophilic interaction liquid chromatography-tandem mass spectrometry method (HILIC-MS/MS) was developed for the simultaneous determination of 28 amphetamine-type stimulants (ATSs) in equine plasma for doping control analysis. In this method, stimulants were recovered from equine plasma by liquid-liquid extraction (LLE) at pH 9.5 using methyl tert-butyl ether and detected on a Thermo Finnigan triple quadrupole mass spectrometer operating in positive-ion mode electrospray ionization. All stimulants were eluted within 7 minutes and baseline separation was achieved for isomeric and isobaric ...
Van Wulfen KK, Bowker RM.To localize substance P (SP) and neurokinin A (NKA) and their receptors in the insertion of the distal sesamoidean impar ligament (DSIL), deep digital flexor tendon (DDFT), and dorsal hoof wall of healthy feet of horses. Methods: 18 healthy feet from horses. Methods: Samples from the dorsal hoof wall and insertion of the DSIL and DDFT of 10 feet were processed for immunocytochemical analysis, using rabbit polyclonal antisera raised against SP and NKA. Tissue sections from 8 feet were incubated with 125-labeled SP to localize tachykinin receptors and their specificity and with control solutions...
Stilson AE, Herring DS, Robertson JT.The radiopacity of the equine cartilaginous nasal septum and its covering mucosa seen on dorsoventral radiographs was determined to be of sufficient density to be useful in the diagnosis of any disorder of this anatomic structure. Radiographically, the frontal and nasal bones dorsally and the vomer and palatine process of the incisive bone ventrally do not completely obscure the nasal septum and its covering mucous membrane.
Mageed M, Dyab S, Swagemakers JH, Gerlach K.The impact of different acquisition times (AqT) and technetium-99 m-labeled ( Tc) diphosphonates on the image quality of bone scintigraphy is poorly documented in horses. The aim of this prospective experimental study was to evaluate the impact of varying Tc-disphosphonates and AqT on semiquantitative and qualitative image parameters of bone scintigraphy in horses. Twenty-four horses undergoing bone scintigraphy were divided equally and randomly into methylene- (MDP), hydroxymethylene- (HDP), and dicarboxypropane diphosphonate (DPD) groups. Lateral scintigraphic images of the antebrachium we...
Liley H, Zhang J, Firth E, Fernandez J, Besier T.Population variance in bone shape is an important consideration when applying the results of subject-specific computational models to a population. In this letter, we demonstrate the ability of partial least squares regression to provide an improved shape prediction of the equine third metacarpal epiphysis, using two easily obtained measurements.
Chan CW, Collins EA.An angiosarcoma involving the right frontal and maxillary sinuses in a nine-year-old Thoroughbred mare was studied post mortem by light and electron microscopy. Important diagnostic features included malignant endothelial cells lining ill-defined vascular spaces, supported by other vasoformative elements. Rhabdomyoblasts were also found. The tumour is apparently rarely seen in the nasal passages of the horse.
Gaul CE, Rich AF, Ressel L, Hinnigan GJ, Owen KR.This study aimed to determine whether a true synovial structure exists over the olecranon tuberosity, which could be attributed to a noninflamed olecranon bursa. Contrast radiography, gross anatomical dissection, and histopathology were used to evaluate the olecranon bursa in horses with no previous elbow pathology. The radiographic study revealed that the contrast was positioned subcutaneously, superficial to the long head of the triceps and its insertion on the olecranon tuberosity and did not extend cranial to the triceps tendon. The contrast region was consistent in shape, size, and locati...
Wichtel ME, Buys E, DeLuca J, Stringel G.This article focuses on the pharmacologic properties of drugs commonly used in the treatment of neonatal septicemia and its complications. Rational therapy demands an awareness of not only the pharmacology of individual drugs but also the interactions and anticipated fate of such drugs in the rapidly changing physiologic environment of the neonate. Further research in the area of equine neonatal pharmacology should greatly assist our understanding of the impact of the disease state on the unique physiology of the newborn and should allow us to better predict the ultimate fate of drugs commonly...
Clark ES, Becht JL.This article discusses the various drugs that affect the equine gastrointestinal tract. Drugs that alter intestinal motility, that protect the gastrointestinal tract, and that alter secretions, as well as analgesics, appetite stimulants, and orally administered antimicrobial agents are reviewed.
Lotstra RJ, van den Broek J, Power T, Marr CM, Wijnberg ID.Atrial fibrillation is a common equine arrhythmia. Quinidine alone, or with digoxin are common treatments. Studies on outcome in Warmblood populations in which duration of the AF is often unknown are limited. Objective: To identify the factors that are associated with the success of full treatment cardioversion with oral medication, and establish whether there are differences in these factors between institutions. Methods: Retrospective case series using patient records of Equine University Clinic of Utrecht University and Rossdales Equine Hospital, Newmarket. Methods: Forty-nine horses treate...
Losch K, Heinze W, Mieth K.The formula proposed by RITSCHEL (1973) for calculation of rates of resorption is explained and modified for use of the monocompartment model. Resorption rates were calculated for cattle, calf, horse, and sheep, with reference being made to the example of Mebacid tablets. The most favourable rate of resorption was established for calf.
Solter PF, Farner S.The purpose of this study was to compare 2 different nonradioactive assay methods with a conventional radioimmunoassay (RIA) measuring the concentration of serum thyroxine (T4) in horses. Serum was obtained from 85 adult standardbred horses. The T4 concentration of each sample was analyzed by RIA, chemiluminescent enzyme immunoassay (CEI), and homogeneous enzyme immunoassay (HEI). The correlation between the HEI method and RIA method was significantly greater (r = 0.89) than the correlation between the CEI and the reference method (r = 0.53). In addition, the precision of the HEI method was si...