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.
Brown MP, MacCallum FJ.Tetracycline-labeled bones of 23 foals from 52 to 104 days old were sectioned and macroscopically examined to assess the extent of ossification or fusion of ossification centers. A grading system was devised with which to record information about the ossification centers and growth plates. The objective was to define anatomic standards which could contribute toward obtaining an accurate radiologic interpretation. Labeled limb bones of 3 neonatal foals were similarly treated, but grading of these was limited to the consideration of whether each site was still cartilaginous or had commenced to o...
Gronwall R, Engelking LR, Anwer MS, Erichsen DF, Klentz RD.Surgically placed bile duct cannulas allowed collection of secreted bile from nonanesthetized ponies. UNINTERRUPTED ENTEROPHEPATIC CIRCULATION WAS PERMITTED BETWEEN COLLECTIONS. Deleterious effects of cannulation were not observed. Average bile flow was 18.6 plus or minus 1.72 (standard error) mul/minute/kg, bile acid excretion was 0.179 plus or minus 0.0212 mumole/minute/kg, and bilirubin excretion averaged 1.22 plus or minus 0.136 mug/minute/kg.
Rawlings CA, Byars TD, Van Noy MK, Bisgard GE.Activated coagulation test (ACT) was performed in 37 adult ponies and 31 adult horses. The mean ACT time of all ponies and horses was 2 minutes 38 seconds, with a standard deviation (SD) of 29 seconds. The ACT was compared with the Lee-White clotting test in heparinized ponies. The correlation of ACT with the Lee-White test was 0.95. Anticoagulation heparinized ponies during prolonged cardiopulmonary bypass was successfully monitored with the ACT. The ACT is simple and reproducible, has a definite end point, and would seem to be an ideal screening test for hemorrhagic diathesis in equine anima...
Kamerling JP, Vliegenthart JF.A number of O-acetylated N-acylneuraminic acids, isolated from submandibular glands of cow and horse and from horse erythrocytes, have been characterized by mass spectrometry. On the basis of the typical fragmentation patterns of the pertrimethylsilyl derivatives of the methyl esters of the compounds, they were identified as 4-O-acetyl-, 9-O-acetyl-, 4,9-di-O-acetyl-, and 7,9-di-O-acetyl N-acetylneuraminic acid, and 4-O-acetyl-and 9-O-acetyl-N-glycolylneuraminic acid.
Inkerman PA, Scott K, Runnegar MT, Hamilton SE, Bennett EA, Zerner B.Chicken, sheep, and horse liver carboxylesterases have been purified by procedures involving ammonium sulfate fractionation, ion-exchange chromatography and gel filtration on Sephadex. The actual yields of the procedures described were as follows: chicken, 1 g from 2 kg of liver powder (chloroform-acetone); sheep, 200 mg from 400 g of powder (chloroform-acetone); horse, 230 mg from 800 g of powder (acetone). The purified enzymes are free of non-carboxyl-esterase protein as shown by gel electrophoresis, although they do contain electrophoretic variants. The equivalent weight of the chicken enzy...
Holmes JR, Rezakhani A.The paper describes changes observed in the T wave and T vectorcardiogram in horse after various periods of exercise. Using radiotelemetry and a bipole lead all horses showed negative T waves immediately after exercise. In some of them this was followed by a markedly positive T deflection. Possible reasons for these changes are briefly discussed.
Bhavnani BR, Martin LJ, Baker RD.A mixture of 1-14C-isopentenylpyrophosphate and 3H-dehydroisoandrosterone was injected into a horse fetus intramuscularly during laparotomy, after which maternal urine was collected for 4 days. Steroid conjugates in the urine were extracted with Amberlite XAD-2 resin, hydrolysed and separated into phenolic and neutral fractions. From the phenolic fraction estrone, 17alpha-estradiol, equilin and equilenin were isolated. Only estrone and 17alpha-estradiol contained both 3H and 14C, while the ring B unsaturated estrogens contained only 14C. From the neutral fraction 14C-labeled 3beta-hydroxy-5alp...
Hughes JP, Kennedy PC.TWo cases of XO-gonadal dysgenesis in the mare are presented. Case No 1 was a pure 63, XO, while Case No 2 was a mosaic with a preponderance of XX cells. The clinical picture was one of phenotypically normal female mares with small uteri and infantile ovaries. The ovaries lacked germ cells, and consisted of stroma only. This study emphasizes the importance of chromosome analysis in providing information concerning the mechanisms involved is some cases of equine infertility.
Jones RS.Surgical repair of a cleft palate was carried out in three horses. Mandibular symphisotomy allowed adequate exposure of the defect. The first subject, a young foal died from inhalation pneumonia but the other two made satisfactory recoveries. The problems of closure of the lip and symphysis are discussed.
Cermák O.The paper describes the relation of citric acid to other chemical and biological indices of the fertility of stallion sperm. A positive relation was found between citric acid and the density and motility of spermatozoa, to the concentration of ergothioneine, and hemolytic activity, and a negative relation to pH and to the polarographic activity of proteins. Attention is drawn to the important nutritional function of citric acid.
Crowhurst RC.Diseases of the back of horse and man are not comparable owing to the great difference in anatomy and posture. Veterinary surgeons, particularly in the United Kingdom, are often requested to account for a poor performance due to suspected "back trouble" but a complete examination of the horse's back is most difficult and care must be taken first to exclude any limb or foot lesions. Diseases of the bones, nerves and muscles are briefly discussed. Diagnosis must be improved by new radiographic and biochemical tests before the significance of back lesions can be assessed or even treated.
Rossdale PD.The place of clinical research in the veterinary profession is discussed against the author's personal experiences and in the context of how research workers, clinicians, teachers and veterinary students might be brought into a more cohesive unit through the development of a Faculty of clinical research and experimental medicine. It is argued that students should receive training in research and teaching and that efforts should be made to break down the attitude of "them" and "us" which tends to separate the clinicians and academics.
Routledge NB, Harris RC, Harris PA, Naylor JR, Roberts CA.The variation over 24 h of plasma glutamine concentration in nonexercising horses was studied in 3 Thoroughbreds (TB) fed at 1600 h and 0700 h. This indicated a small but regular change associated with feeding. Starting at a mean of 482 mumol/l at 1600 h the concentration increased to 522 mumol/l at 2000 h, falling to 476 mumol/l at 1600 h and increasing again to 525 mumol/l at 2000 h. 'Normal' values were established in 19 part-bred TB horses, lacking clinical signs or remarkable pathology and in light training, by sampling weekly at 1000 h over a 10 week period. The mean concentration was 49...
Ousey JC, Rossdale PD, Cash RS, Worthy K.Multiparous pregnant mares, on two studfarms, were studied following natural challenge with equid herpesvirus-1 (EHV-1). They were divided into three groups according to serum complement fixation titres: Group A (N = 11) were not challenged and delivered normal foals; Group B (N = 13) were challenged but delivered normal foals; Group C (N = 23) were challenged and delivered infected foals which were stillborn or lived for less than 31 h. In Groups A and B mean (+/- s.d.) gestational age at delivery was 343 (+/- 8) and 339 (+/- 8) days respectively, whereas in Group C it was significantly (P le...
Staszyk C, Jackowiak H, Godynicki S, Gasse H.The microvascularisation of the equine non-glandular gastric mucosa was investigated using corrosion casts for scanning electron microscopy. Specimens from 11 healthy horses were examined. Corresponding to the high incidence of gastric lesions in the margo plicatus, special attention was paid to the differentiation between the pars nonglandularis and the margo plicatus as a distinct area of the aglandular mucosa. In both areas, the blood vessels of the lamina propria mucosae were arranged in three vascular layers; i. e. I) a basal, II) an intermediate, and III) a subepithelial horizontal level...
Bennett D.The gross and histological features of multiple bone infection in two foals are described. In both cases the lesions were confined to the region of the growth plate. Bone and, in some cases, growth plate cartilage destruction has occurred associated with an extensive inflammatory cell infiltration. The significance of the pathological observation is discussed in relation to the pathogenesis of bone infection in the foal.
Coyne CP, Smith JE, DeBowes RM.Several pharmaceutical compounds were evaluated for their ability to selectively inhibit activated coagulation factor-XIII-like enzyme activity (eg, XIIIa*) in pooled equine plasma. Presence of coagulation factor-XIIIa*-like enzyme activity in plasma was established by assay procedures involving incorporation of the fluorescent amine compound, monodansylcadaverine, into purified casein, which served as a protein substrate. Pharmaceuticals inhibitory to coagulation factor-XIIIa*-like enzyme activity were recognized by plasma gel formation of high spectrophotometric transmittance (transparency),...
Blunden AS, Gower SM.Lungs were obtained from 16 Thoroughbred horses, aged 1 day to 2 years, which had died or been humanely killed for reasons unrelated to disease of the lower respiratory tract. The lungs were then subjected to a histological and immunohistochemical examination of the humoral immune system. At birth there was no evidence of organized lymphoid tissue, and lymphocytes and plasma cells were virtually absent in all tissue compartments in the first week of life. However, by 12 weeks, foals exhibited well developed bronchus- and bronchiole-associated lymphoid tissue, but this had regressed progressive...
Batt RM, Burgess D, Edwards GB, van de Waal S, Sørensen SH, Hart CA.To examine the postnatal development of equine small intestine, biopsy specimens of jejunal mucosa from 8 ponies, between 6 and 28 weeks old, were subjected to analytical subcellular fractionation and assay of organelle marker enzymes. Fractionation revealed a reduction in the particulate brush border component of beta-galactosidase (lactase) activity between 6 and 28 weeks, and a corresponding increase in soluble activity, although the reduction in mean specific activity was not significant. There also was a decrease in the proportion of brush border to soluble aminopeptidase N activity, a re...
Alexander S, Irvine CH.Mares were bled once daily throughout a cycle, or 3 times daily from the first day of oestrus to the 2nd day after ovulation. LH was measured by heterologous radioimmunoassay and by an in-vitro bioassay based on LH-stimulated testosterone production by mouse Leydig cells. The patterns of bio- and immuno-active LH during the oestrous cycle were similar but not identical, so that in both groups of mares the ratio of biological: immunological (B:I) activity during the LH surge was significantly higher before than after ovulation (P less than 0 . 001). Considerable individual variation in cycle me...
Wood T, Tai CL, Taylor DG, Woods WE, Wang CJ, Houtz PK, Tai HH, Weckman TJ, Yang JM, Sturma L.Detomidine is a potent non-narcotic sedative agent which is currently in the process of being approved for veterinary clinical use in the United States. Since no effective screening method in horses is available for detomidine, we have developed an 125I radioimmunoassay for detomidine in equine blood and urine as part of a panel of tests for illegal drugs in performance horses. Our 125I radioimmunoassay has an I-50 for detomidine of approximately 2 ng/ml. Our assay shows limited cross-reactivity with the pharmacodynamically similar xylazine, but does not cross-react with acepromazine, epinephr...
Kikuchi K, Kozai K, Hojo T, Sakatani M, Okuda K, Bai H, Kawahara M, Takahashi M.We investigated the electrical impedance of the reproductive tracts (vagina and uterine endometrial tissues) and the expression of mucus-related genes to identify the stage of the estrous cycle in mares. We first examined vaginal impedance in native Hokkaido mares during their estrous cycle and found no significant differences. However, impedance levels tended to decrease towards ovulation. Furthermore, we investigated the estrous cycle by measuring the electrical impedance of the uterine endometrial tissues obtained from carcasses of mares. We found that impedance levels in the endometrial ti...
Brom-de-Luna JG, Salgado RM, Felix MR, Canesin HS, Stefanovski D, Diaw M, Hinrichs K.In vitro production of horse embryos via intracytoplasmic sperm injection (ICSI) is a useful clinical and research technique. Current rates of blastocyst production are typically sub-optimal, and few methods to increase the rate of equine blastocyst development have been reported. Factors that might improve blastocyst production in a horse embryo culture system were explored. Myo-inositol is found in the horse oviduct and improves blastocyst development in other species, thus Experiment 1 was conducted to assess the effect of 10 mM myo-inositol added to Day 0-5 embryo culture medium, using hor...
Dunkel B, Knowles EJ, Chang YM, Menzies-Gow NJ.Blood l-lactate concentrations are higher in people with developing or established diabetes mellitus and insulin resistance. Objective: To investigate whether blood l-lactate concentrations are positively correlated with measures of insulin dysregulation (ID) or increased autumnal ACTH concentrations in ponies. Methods: Systemically healthy client-owned ponies (n = 101). Methods: Prospective case-control study. Blood samples were obtained from 101 clinically healthy ponies. Breed, weight, height, and subjective and objective measures of body condition were recorded. Blood l-lactate, glucose, t...
Paine SW, Aldurdunji M, Garth-Greeves A, Muir T, Hincks PR.Hydroxyzine and cetirizine are first- and second-generation oral antihistamine drugs, respectively, used to treat allergic reactions in horses. Cetirizine is also a metabolite of hydroxyzine, which may lead to complexities in regulating their use in equine sporting events. The aim of the research was to be able to provide detection times (DT) from pharmacokinetic studies in thoroughbred horses to better inform trainers, and their veterinary surgeons, prescribing these substances for treatment of Thoroughbred racehorses. Six and two horses were given 9 repeated administrations of hydroxyzine HC...
Abd El Kader NA, Farghali HA, Abu-Seida AM, Salem NY, Khattab MS.Early detection of cystitis in equine is essential to improve the prognosis and outcome of therapy. However, the conventional white light endoscopy is not sufficiently accurate for this purpose. Hence, this study evaluated chromoendoscopy as a recent diagnostic tool for cystitis in female donkeys. For this purpose, 5 apparently normal donkeys (control group) and 5 female donkeys with cystitis (diseased group) were used. Physical and rectal examinations, urine analysis, white light cystoscopy, methylene blue-based chromoendoscopy and histopathology were performed in all animals. Turbid urine ex...
Johns I, McParland T, Mair T.Pleural effusion (PE) is reported to occur most commonly secondary to bacterial pneumonia or lung abscesses, with neoplastic effusions contributing the minority of cases. The majority of these reports originate from America and Australia, where long distance transport of horses, a recognised risk factor, appears to occur more frequently. Anecdotally, neoplastic PE is more commonly diagnosed in the UK. Objective: To describe the causes of PE in horses resident in the UK, and to identify potential markers that can help differentiate between infectious and neoplastic causes of PE. Methods: Retros...
Thompson DL, Johnson L.Prolactin concentrations in stallion serum were measured by radioimmunoassay based on antiserum generated against equine prolactin and radioiodinated canine prolactin. Prolactin concentrations in serum collected from 152 stallions at a slaughterhouse were higher (P less than .01) in summer than in winter (5.7 +/- .15 vs 2.0 +/- .17 ng/ml). Moreover, there was an effect of age (P less than .02) in the analysis of variance; there was no interaction between age and season. In general, prolactin concentrations increased with age up to 3 to 5 years. Samples of serum collected from five control and ...
Tyrnenopoulou PC, Rizos ED, Kritsepi-Konstantinou M, Papadopoulou PL, Patsikas MN, Papazoglou LG, Aggeli A, Diakakis NE.To determine whether differences existed in the viscoelastic properties of synovial fluid samples from the metacarpophalangeal, intercarpal, and distal interphalangeal joints of orthopedically normal athletic horses. Methods: 45 warmblood horses and 30 Thoroughbreds (age range, 4 to 16 years). Methods: Synovial fluid samples were aseptically obtained via arthrocentesis from 1 metacarpophalangeal, intercarpal, and distal interphalangeal joint of each horse, and nucleated cell counts were performed. A commercial ELISA was used to measure sample hyaluronic acid concentrations, and full rheologica...
Klier J, Geis S, Steuer J, Reese S, Fuchs S, Mueller RS, Winter G, Gehlen H.New therapeutic strategies to modulate immune responses in human and equine allergic airway diseases are under extensive investigation. Stimulation of Treg cells with immune modulating agents is a novel therapeutic option. Objective: The aim of this field study was to compare the effects of a nebulised nanoparticulate CpG immunotherapy (CpG-GNP) with and without specific allergens. Methods: Longitudinal clinical study comparing 2 therapeutic options. Methods: Twenty RAO-affected horses were divided into 2 treatment groups (CpG alone and CpG with allergens). Two specific allergens were selected...
Albright JD, Witte TH, Rohrbach BW, Reed A, Houpt KA.Crib-biting is a common oral stereotypy. Although most treatments involve prevention, the efficacy of various anti-crib devices, including surgically implanted gingival rings, has thus far not been empirically tested. Objective: Demonstrate the effect that 2 anti-crib collars, muzzle and gingival rings have on crib-biting, other maintenance behaviours, and cortisol levels in established crib-biting horses. Methods: Randomised, crossover clinical trial. Methods: In Experiment I, 2 anti-crib collars and a muzzle were used on 8 established crib-biting horses; horses wore each of 3 devices for 7 d...
Harada K, Akioka K, Izu I, Sasaki N.Hemorrhage syndrome in adipose tissues in the crest of the neck (HSCN), specifically in hemorrhagic adipose tissues on the longitudinally sectioned surface of the neck fat at the dorsal nuchal ligament, is prevalent in heavy horse breeds. Herein, we aimed to establish an ultrasonographic method to successfully diagnose HSCN in heavy horse breeds and assess its efficacy. Horses with homogeneous echogenicity images were included in the control group, whereas those with linear high-echogenicity images were classified as having HSCN. Horses with confirmed linear high-echogenicity images exhibited ...
Löhr CV, Polster U, Kuhnert P, Karger A, Rurangirwa FR, Teifke JP.Actinobacillus suis-like organisms (ASLOs) have been isolated from the genital, respiratory, and digestive tracts of healthy adult horses, horses with respiratory disease, and septic foals. Two foals with congenital hypothyroidism-dysmaturity syndrome from separate farms developed ASLO infection. At necropsy, both had contracted carpal flexor tendons, thyroid hyperplasia, and thrombotic and necrotizing mesenteric lymphangitis and lymphadenitis; one foal also had mandibular prognathism. Numerous ASLOs were isolated from tissues from both foals, including intestine. Biochemical testing and mass ...
Allen BV.The assay of serum folate has been used to investigate the folate status of thoroughbreds in training to race, in-foal thoroughbred mares at stud and crossbred ponies kept permanently at grass. Throughbreds in training, with no obvious haematological or clinical abnormalities, had lower serum folate levels (mean 3.3, range 1.5 to 6.1 microgram per litre) compared with thoroughbred mares at stud (mean 10.6, range 6.4 to 15.8 microgram per litre) and crossbred ponies at grass (mean 10.9, range 7.4 to 16.6 microgram per litre. Intensive exercise, over a period of six months, significantly decreas...
Landim-Alvarenga FC, Alvarenga MA, Seidel GE, Squires EL, Graham JK.Experiments evaluated the ability of follicular fluid (FF), dilauroylphosphatidylcholine (PC12) and the calcium ionophore A23187 (A23187) to induce capacitation in stallion and bull spermatozoa, determined by the ability of the spermatozoa to penetrate zona-free hamster, bovine and equine oocytes. Spermatozoa suspensions were incubated at 37 degrees C in one of the following treatments: 1) a modified Tyrode's medium (BGM3) alone; 2) BGM3 + FF; 3) BGM3 + PC12; 4) BGM3 + FF + PC12; 5) BGM3 + A23187; and 6) BGM3 + FF + A23187. Treated spermatozoa were incubated with zona-free hamster, bovine and ...
de Graaf-Roelfsema E, Veldhuis PP, van Dam KG, Menheere PP, Keizer HA, Johnson ML, van Breda E, Wijnberg ID, van der Kolk JH.Defining normal Growth Hormone (GH) secretory dynamics in the horse is necessary to understand altered GH dynamics related to issues like welfare and disease. Methods: Twelve healthy yearlings and two mature Standardbreds were used to quantify GH secretion. Endogenous GH half-life was determined after administration of 1.0 µg/kg BW GH releasing hormone (GHRH). Exogenous GH half-life was determined after administration of 20 µg/kg BW recombinant equine GH (reGH) with and without suppression of endogenous GH secretion by somatostatin infusion (50 µg/m(2)/h). Pulse detection algorithm (C...
Hauser ML.The diagnostician should be familiar with the normal ultrasound appearance (size, shape, position, and textural quality) of each structure examined. With these factors as reference points, one can describe lesions in the structure involved, the precise location and extent of the lesions, and the degree of structural compromise that is manifested. Documentation of lesions of tendons and ligaments enables one to make an accurate diagnosis and a more precise prognosis. Serial examination during the healing phases allows for a more accurate prediction as to when the structure in question can withs...
Mutoh K, Watanabe S, Wakuri H.The glands of pelvis renalis in adult and fetal horses were examined by histochemically. The glandular terminal was divided into two types, intraepithelial gland (IE) and extraepithelial gland (EE) by their locations and histochemical characters. Both glands were composed of mucous cells. The former lay in the transitional epithelium and were stained reddish with galactose oxidase-Schiff (GOS) and mild oxidation-Schiff (MOS), bluish purple with periodic acid-cold thionine Schiff-NaOH-PAS (PCP). The latter distributed in the lamina propria, but was not discovered in the fetus. They were stained...
Theiner E, Weber C, Müller E, Venner M, Vervuert I.This study aimed to establish reference intervals for Mn in whole blood, plasma and serum of healthy, adult warmblood horses with known dietary Mn intake and to compare 2 methods of analysis. Methods: Between May 2018 and November 2019 a single blood sample was taken from a total of 270 clinically healthy horses (age: 3-25 years) in 3 stud farms. In lithium-heparin (LH) whole blood, LH plasma and serum Mn concentrations were analyzed by means of atomic absorption spectrometry (AAS) and inductively coupled plasma mass spectrometry (ICP-MS). The reference intervals were calculated according to t...
Belgrave RL, Hines MT, Keegan RD, Wardrop KJ, Bayly WM, Sellon DC.The development of ultrapurified hemoglobin-based oxygen carriers has eliminated many problems associated with whole-blood transfusions in other species. We hypothesized that the administration of polymerized ultrapurified bovine hemoglobin (PUBH) would result in improved hemodynamic parameters in ponies with normovolemic anemia without adverse effects on renal function or coagulation times. Normovolemic anemia was induced in 6 healthy adult ponies. Over a 3-day period, at least 45 mL/kg of whole blood was withdrawn from each pony until a target PCV of <12% was attained. Plasma was separate...
The importance of the horse industry to the economy of the United States and the impact of parasitic infections on the industry are well documented. However, contemporary research activity on internal parasites of horses has not kept pace with growth of the horse population. Parasitic infections are a major facet of enteritis and colic in horses. Parasites are also associated with poor growth and development, respiratory tract disease, dermatitis, and CNS lesions. Babesia infections remain a threat to horses imported from some regions of the world. Most research activity has dealt with the dev...
Sod GA, Riggs LM, Mitchell CF, Martin GS, Gill MS.To compare number of cycles to failure for palmarodorsal 4-point bending of a modified 5.5 mm broad locking compression plate (M5.5-LCP) fixation with a 5.5 mm broad LCP (5.5-LCP) fixation used to repair osteotomized equine third metacarpal (MC3) bones. Methods: In vitro biomechanical testing. Methods: Adult equine cadaveric MC3 bones (n=6 pairs). Methods: An 8-hole, M5.5-LCP, obtained by having a 1.0 mm thickness removed from the bone contact portion of the 5.5-LCP, was applied to the dorsal surface of 1 randomly selected MC3 from each pair, and an 8-hole, 5.5-LCP was applied dorsally to the ...
