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.
Daly J, Daas A, Behr-Gross ME.In 2004, the Office International des Epizooties (OIE) Expert Surveillance Panel on equine influenza recommended that the American lineage component (H3N8) of equine influenza vaccines (A/eq/Newmarket/1/93-like) be updated to an A/eq/South Africa/4/03-like virus. As a consequence the common European Pharmacopoeia (Ph. Eur.) - OIE reference for equine influenza subtype 2 American-like antiserum had to be complemented by an antiserum raised in horses against an A/eq/South Africa/4/03 strain. An international collaborative study run by the European Directorate for the Quality of Medicines (EDQM) ...
Hobo S, Niwa H, Anzai T.The reactivity of the proline-glutamic acid-proline-lysine (PEPK) repetition peptide antigen in 3176 serum samples was investigated to evaluate its utility as an antigen for the serological diagnosis of strangles. The reactivity of the sera of horses infected with Streptococcus equi subspecies equi was high when the peptide had several PEPK repetitions. However, as the number of PEPK repetitions increased, the reactivity of the antigen with the sera of horses infected with Streptococcus equi subspecies zooepidemicus also increased. In horses infected experimentally with S equi, the reactivity ...
Vonaparti A, Lyris E, Panderi I, Koupparis M, Georgakopoulos C.Two simple and rapid LC/MS methods with direct injection analysis were developed and validated for the quantification and identification of hydrocortisone in equine urine using the same sample preparation but different mass spectrometric systems: ion trap mass spectrometry (IT-MS) and time-of-flight mass spectrometry (TOF-MS). The main advantage of the proposed methodology is the minimal sample preparation procedure, as particle-free diluted urine samples were directly injected into both LC/MS systems. Desonide was used as internal standard (IS). The linear range was 0.25-2.5 microg ml(-1) for...
Huthmann S, Gasse H, Jacob HG, Rohn K, Staszyk C.The equine cheek tooth battery is part of a very dynamic system. The aim of this study was to investigate whether the curvature and position of the teeth are also involved in such dynamical processes. The alveolar crest was labelled with a radiodense marker (48 cadaver heads, 15 skulls) and laterolateral radiographs were taken. Then a geometrical method was elaborated to determine a cheek tooth's curvature and its position by means of specific angles. This method respects the remarkable changes of the equine dentition throughout life by considering two items: (1) the alveolar crest was taken a...
Endo A, Roos S, Satoh E, Morita H, Okada S.Two strains of lactic acid bacteria were isolated from faeces of two actively racing thoroughbred horses. The isolates formed a subcluster in the Lactobacillus reuteri phylogenetic group, closely related to Lactobacillus fermentum, L. gastricus, L. ingluviei and L. mucosae, by phylogenetic analysis based on 16S rRNA gene sequences. Levels of DNA-DNA relatedness revealed that the isolates belonged to the same taxon and were genetically separated from their phylogenetic relatives. Biochemical and physiological characteristics also distinguished the isolates from their phylogenetic relatives. The...
Haase B, Jude R, Brooks SA, Leeb T.The tobiano white-spotting pattern is one of several known depigmentation phenotypes in horses and is desired by many horse breeders and owners. The tobiano spotting phenotype is inherited as an autosomal dominant trait. Horses that are heterozygous or homozygous for the tobiano allele (To) are phenotypically indistinguishable. A SNP associated with To had previously been identified in intron 13 of the equine KIT gene and was used for an indirect gene test. The test was useful in several horse breeds. However, genotyping this sequence variant in the Lewitzer horse breed revealed that 14% of ho...
Sebastian MM, Stewart I, Williams NM, Poonacha KB, Sells SF, Vickers ML, Harrison LR.Pathological, entomological and avian investigations were conducted during the summer of 2002, in a horse farm that had four cases of West Nile virus (WNV) infection in horses. All the four horses had encephalitis and WNV infection was confirmed by RT-PCR and in situ hybridization procedure. Forty-seven per cent of house sparrows that resided on the farm were tested positive for WNV infection. Mosquitoes (98%Culex pipiens) collected by trapping at the farm, during this period were positive for WNV. The meteorological data for year 2002 were compared to previous 16 years. The precipitation and ...
Barakzai SZ, Kane-Smyth J, Lowles J, Townsend N.To examine 2 rostral maxillary sinus (RMS) trephine sites for safety and efficacy using skulls of horses of varying age. Methods: Descriptive study. Methods: Cadaveric equine skulls (n=40). Methods: Two RMS trephination sites (rostral, caudal) were made in each skull. Radiographic projections using markers at each site were used to determine if sites were within the RMS and directly overlying a cheek tooth. Sinusotomy in 14 skulls was used to determine correlation between radiographic and anatomic location of trephine sites, and of the rostrolateral aspect of the maxillary septum. Age-related ...
Sod GA, Mitchell CF, Hubert JD, Martin GS, Gill MS.To compare monotonic biomechanical properties and fatigue life of a broad locking compression plate (LCP) fixation with a broad limited contact dynamic compression plate (LC-DCP) fixation to repair osteotomized equine third metacarpal (MC3) bones. Methods: In vitro biomechanical testing of paired cadaveric equine MC3 with a mid-diaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation. Methods: Cadaveric adult equine MC3 bones (n=12 pairs). Methods: MC3 were divided into 3 groups (4 pairs each) for: (1) 4-point bending single cycle to failure testing; (2) 4-point bending cyclic ...
Sod GA, Mitchell CF, Hubert JD, Martin GS, Gill MS.To compare monotonic biomechanical properties and fatigue life of a 5.5 mm broad limited-contact dynamic compression plate (5.5-LC-DCP) fixation with a 4.5 mm broad LC-DCP (4.5-LC-DCP) fixation to repair osteotomized equine third metacarpal (MC3) bones. Methods: In vitro biomechanical testing of paired cadaveric equine MC3 with a mid-diaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation. Methods: Adult equine cadaveric MC3 bones (n=18 pair). Methods: MC3 were divided into 3 test groups (6 pairs each) for: (1) 4-point bending single cycle to failure testing; (2) 4-point bendi...
Votion DM, Linden A, Delguste C, Amory H, Thiry E, Engels P, van Galen G, Navet R, Sluse F, Serteyn D, Saegerman C.Over the last decade, atypical myopathy (AM) in grazing horses has emerged in several European countries. An exploratory analysis was conducted to determine horse- and pasture-level indicators or factors associated with AM in Belgium. Belgian cases of AM confirmed by histology (n=57) were compared to their healthy co-grazing horses (n=77) and to pastured horses not involved with AM as controls (n=386). The pastures where confirmed cases were grazing (42 pastures; 38 sites; 44 incidences of AM) were compared with those of the controls (216 pastures; 96 sites; no incidence of AM). Statistically ...
Manso Filho HC, Costa HE, Wang Y, McKeever KH, Watford M.Glutamine plays important roles in the interorgan transport of nitrogen, carbon and energy but little is known about glutamine metabolism in the horse. In this study we determined the tissue distribution of glutamine synthetase expression in three Standardbred mares. Expression of glutamine synthetase was highest in kidney and mammary gland, and relatively high in liver and adipose tissue. Expression was lower in gluteus muscle, thymus, colon and lung, and much lower in small intestine, pancreas and uterus. The pattern of glutamine synthetase expression in the horse is similar to that of other...
Phumoonna T, Barton MD, Vanniasinkam T, Heuzenroeder MW.Rhodococcus equi remains a significant bacterial pathogen, causing severe pyogranulomatous pneumonia in foals aged 1-3 months. There is no effective vaccine currently available for the prevention of R. equi pneumonia. DNA vaccines are known to offer specific advantages over conventional vaccines. The aim of this study was to demonstrate efficacy of our recombinant DNA vaccine candidates, namely pcDNA3-Re1, pcDNA3-Re3 and pcDNA3-Re5 by combining a heat shock protein GroEL2 to a virulence-associated protein A (VapA) from R. equi to protect C3H/He mice against the R. equi infection. VapA was show...
Chaffin MK, Cohen ND, Martens RJ.To determine the effect of azithromycin chemoprophylaxis on the cumulative incidence of pneumonia caused by Rhodococcus equi, age at onset of pneumonia, and minimum inhibitory concentration (MIC) of azithromycin for R equi isolates cultured from fecal and clinical samples. Methods: Controlled, randomized clinical trial. Methods: 338 foals born and raised at 10 equine breeding farms; each farm had a history of endemic R equi infections. Methods: Group 1 foals were control foals, and group 2 foals were treated with azithromycin (10 mg/kg [4.5 mg/lb], PO, q 48 h) during the first 2 weeks after bi...
Garvican ER, Vaughan-Thomas A, Redmond C, Clegg PD.Matrix degradation by metalloproteinases is considered a key feature in the loss of articular cartilage seen in many joint diseases. Membrane-type matrix metalloproteinase-3 (MT3-MMP) expression is elevated in human cartilage in end-stage osteoarthritis. We investigated whether MT3-MMP is similarly regulated in cartilage in two naturally occurring arthropathies in vivo and whether proinflammatory cytokines regulate its expression in vitro. MT3-MMP expression was evaluated in cartilage from horses with osteoarthritis and osteochondrosis and compared with age- and site-matched normal cartilage. ...
Takeuchi K, Murakami A, Sekiguchi A, Hirata Y, Maeda K, Kitahori K, Doi Y, Takamoto S.Right ventricular outflow tract obstruction is a frequent condition after Rastelli operation. Although several modifications have been reported elsewhere, ideal conduit has not been developed yet during long-term follow-up. We reviewed our experiences over 15-year long-term follow-up with patients who underwent Rastelli operation using house-made equine pericardial roll graft. Methods: Since June 1981, 16 patients underwent Rastelli operation with the pericardial roll graft. Median follow-up time was 15.6 years (7.3-26.8 years). Results: Twelve out of 16 patients using pericardial roll graft w...
Guan F, Uboh CE, Soma LR, Birks E, Chen J, You Y, Rudy J, Li X.Recombinant human erythropoietin (rhEPO) and darbepoetin alfa (DPO) are protein-based drugs for the treatment of anemia in humans by stimulating erythrocyte production. However, these agents are abused in human and equine sports due to their potential to enhance performance. This paper describes the first method for differentiation and identification of rhEPO and DPO in equine plasma by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method comprised analyte extraction and enrichment by immunoaffinity separation with anti-rhEPO antibodies, dual digestion by trypsin an...
Cunha AP, Bello AC, Leite RC, Bastianetto E, Ribeiro AC, Freitas CM, Oliveira PR.The aim of this study was to verify the efficiency of a strategic control program of Amblyomma cajennense in horses under field conditions. Acaricide treatments were applied at seven days intervals and divided in two series, the first one beginning in April 2004 (eight treatments), and the second one beginning in July 2004 (five treatments), aiming to control larvae and nymphs of the tick. A pyrethroid chemical base cypermethrin 0.015% was used for spraying the horses. There was a reduction of 44.85% in the adults infestation of the tick in the period of October 2004 to March 2005, and 59.74%,...
Cunha AP, Bello AC, Leite RC, Ribeiro AC, Freitas CM, Bastianetto E, Oliveira PR.The objective of this study was to evaluate the effect of the Amblyomma cajennense strategic control program on the Anocentor nitens population. The acaricide treatments were carried out every seven days and divided in two series, the first one beginning in April 2004 (eight treatments) and the second beginning in July of the same year (five treatments), using pyrethroid chemical base - cypermethrin in the concentration of 0,015%. Monthly it was evaluated the infestation of A. nitens in the ear and nasal diverticulum of the equines before (October 2003 to March 2004) and after (October of 2004...
Hastie PM, Mitchell K, Murray JA.There is a need to further our understanding of the role that the equine hindgut ecosystem plays in digestive processes and diseases. The aim of the present study was to utilise the real-time PCR technique to determine the abundance of candidate cellulolytic (Ruminococcus flavefaciens; Fibrobacter succinogenes) and non-cellulolytic (Streptococcus bovis) bacteria in lumen contents from the caecum, ventral and dorsal colon, and rectum of healthy horses (n 14). Total DNA was extracted from frozen and lyophilised lumen contents, and PCR primers and Taqman probes were designed based on 16S rDNA seq...
Hoffmann C, Ellenberger C, Mattos RC, Aupperle H, Dhein S, Stief B, Schoon HA.This paper describes the histomorphological and immunohistochemical characterisation of phenotypic variations of endometrosis as well as potential etiological factors which may influence disease progression. In total, 779 endometrial biopsies were examined. These biopsies were taken in the breeding and non-breeding season (n=509), on defined days during the estrous cycle (n=70) and before and after experimentally induced bacterial endometritis (n=200). In addition to conventional histopathology, selected biopsies were investigated using alcianblue staining as well as immunohistochemical method...
McFarlane D, Holbrook TC.Equine pituitary pars intermedia dysfunction (PPID) is the result of a loss of dopaminergic inhibition of the pars intermedia secondary to neurodegeneration of periventricular hypothalamic neurons. The pathologic events contributing to development of neurodegeneration or clinical signs in equids with PPID are unknown. Chronic inflammation may contribute to initiation or progression of PPID. Objective: Horses with PPID have a distinct systemic cytokine profile compared with that of normal adult or aged horses. The cytokine profile of healthy aged horses differs from that of adult horses. Method...
Sanchez LC, Giguère S, Javsicas LH, Bier J, Walrond CJ, Womble AY.Gastric tonometry is commonly used in humans as an assessment of intestinal mucosal perfusion. Values in healthy foals are currently unknown. Objective: Age, enteral feeding, and omeprazole administration would significantly alter gastric tonometry measurements in neonatal foals. Methods: Nine clinically normal foals were used to assess the effect of age and feeding, and 8 similar foals were used to assess the effect of omeprazole. Methods: At 1, 7, and 14 days of age, gastric intramucosal PCO2 (PgCO2) and arterial blood gas samples were obtained at baseline, immediately after feeding milk, an...
Clayton HM, Lavagnino M, Kaiser LJ, Stubbs NC.To compare effects of 4 types of stimulation devices attached to the hind feet on hoof flight, joint angles, and net joint powers of trotting horses. Methods: 8 clinically normal horses. Methods: Horses were evaluated under 5 conditions in random order: no stimulators, loose straps (10 g), lightweight tactile stimulators (55 g), limb weights (700 g), and limb weights with tactile stimulators (700 g). Reflective markers on the hind limbs were tracked during the swing phase of 6 trotting trials performed at consistent speed to determine peak hoof heights and flexion angles of the hip, stifle, ta...
O'Donohue DD, Smith FH, Strickland KL.A two part survey was carried out in Irish Thoroughbred horses in 1988 and 1989 to establish the incidence and prevalence of developmental skeletal problems, particularly possible manifestations of developmental orthopaedic disease (DOD). Survey One was a retrospective study based on a questionnaire involving the foal crops of 46 stud farms for 3 successive seasons; the 1711 animals initially documented represented 10.46% of Irish foal registrations. The second survey involved repeated monitoring of the 1988 foal crop from birth to 18 months of age on 17 stud farms. The 248 foals initially exa...
Matsui T, Murakami Y, Yano H, Fujikawa H, Osawa T, Asai Y.This experiment was conducted to study phytate degradation and the effect of dietary phytate level on phosphorus absorption in the gastrointestinal tract of horses. Six Thoroughbred horses were fed diets containing low-phytate diet or high-phytate diet for 5 days. The diets were supplemented with Cr2O3 as an unabsorbable marker. The horses were killed 3 h after the last feeding and digesta in some segments of the intestine were collected. In both dietary groups, the daily passage of phytate phosphorus was decreased in the upper small intestine and in the lower large intestine. The daily passag...
Meyers-Brown G, Bidstrup LA, Famula TR, Colgin M, Roser JF.The dynamics of ovarian follicular development depend on a timely interaction of gonadotropins and gonadal feedback in the mare. The development and efficacy of genetically cloned recombinant equine gonadotropins (reFSH and reLH) increase follicular activity and induce ovulation, respectively, but an optimum embryo recovery regimen in superovulated mares has not been established. The objective of this study was to determine if treatment with reFSH followed by reLH would increase the embryo per ovulation ratio and the number of embryos recovered after superovulation in mares. Sixteen estrous cy...
Foreman JH, Grubb TL, Inoue OJ, Banner SE, Ball KT.Objective blinded efficacy data during exercise are lacking on the use of single-dose i.v. nonsteroidal anti-inflammatory drugs (NSAIDs) before, during and after exercise. Objective: Single i.v. doses of either phenylbutazone (PBZ) or flunixin meglumine (FM) would prove more efficacious than negative saline control (SAL) before, during and after exercise in a reversible model of foot lameness. Methods: Six Quarter Horse mares had lameness induced by tightening a set screw against a heart bar shoe 1 h prior to treatment. Randomised blinded treatments included PBZ (4.4 mg/kg bwt i.v.), FM (1.1 m...
Essén-Gustavsson B, Gottlieb-Vedi M, Lindholm A.The aim was to investigate metabolic response in muscle during submaximal treadmill exercise to fatigue, with a special emphasis on adenine nucleotide degradation products such as inosine monophosphate (IMP) in muscle and hypoxanthine, xanthine and uric acid in plasma. Five Standardbred trotters performed treadmill exercise on 2 occasions, once at 7 m/s and once at 10 m/s. Venous blood samples were taken at rest, during exercise and at the end of exercise. Muscle biopsies were taken before and after exercise and muscle temperature was measured before and after exercise. Running time differed a...
Bauquier SH, Kona-Boun JJ.Comparison of the effects of xylazine and romifidine administered perioperatively on the recovery of anesthetized horses. The present study was designed to compare recoveries from anesthesia following the use of romifidine or xylazine in horses. In a prospective blind randomized clinical trial, 28 horses, undergoing elective arthroscopy, were randomly allocated into 2 groups. The intravenous anesthesia protocol used in the xylazine group was: butorphanol [0.02 mg/kg body weight (BW)] and xylazine (0.5 to 0.7 mg/kg BW) for premedication, diazepam (0.1 mg/kg BW) and ketamine (2.2 mg/kg BW) for i...
Grint NJ, Whay HR, Beths T, Yvorchuk K, Murrell JC.To evaluate a thermal nociceptive threshold (TNT) testing device in the donkey, and the influence of potential confounding factors on TNTs. Methods: Two groups (Group 1 and Group 2) of eight castrated male donkeys aged 4-9 years, weighing 105-170 kg. Methods: TNTs were measured by heating a thermal probe on skin until an end-point behaviour (threshold temperature) or a cut-out temperature (51 °C) was reached. The withers and the dorsal aspect of the distal limb were used as sites for TNT testing. The effects on TNT of different confounding factors: the limb tested; rate of heating; and amb...
Perrier M, Manso-Díaz G, Dunkel B.Trigeminal nerve-mediated head-shaking (TNMH) in horses is a diagnosis made by exclusion. Computed tomography (CT) is frequently used to identify any disease process that could cause the clinical signs of head-shaking. Although abnormalities are frequently identified, it is unknown whether treatment of these conditions improves clinical signs. Objective: To ascertain the clinical significance of CT findings in horses presented with a complaint of head-shaking. Methods: Retrospective case series. Methods: CT and patient records were reviewed and all abnormal findings and any treatments subseque...
Reilly L, Habecker P, Beech J, Johnston J, Sweeney C, Hamir A.Abscess of the pituitary gland is a rare condition which has been
described in man (Domingue and Wilson 1977; Ahmed et al. 1989),
ruminants (Taylor and Meads 1963; Moriwaki er al. 1973; Lomas and
Hazell 1983; Perdrizet and Dinsmore 1986) and one horse
(Rumbaugh 1977). The some of infection may be either direct
extension from an adjacent focus or haematogenous spread from a site
elsewhere in the body. In man, pituitary abscess may result from
meningitis, sphenoid sinusitis (Selose et al. 1980), and osteomyelitis
(Rongetti and Daniels 1950). A review of 20 cases of pituitary abscess
in ...
O'Neil MM, Korthanke CM, Scarpa JO, Welsh TH, Cardoso RC, Williams GL.We tested the hypotheses that in winter anovulatory mares (1) both chronic daily injections of estradiol-17β (E2) and subcutaneous E2 implants could enhance pituitary secretion of gonadotropins in response to continuous subcutaneous infusion of native gonadotropin-releasing hormone (GnRH); and (2) the secretory pattern of follicle-stimulating hormone (FSH) in response to continuous subcutaneous infusion of native GnRH is similar to that of luteinizing hormone (LH) but differs between mares that develop or fail to develop an estrogen-active, preovulatory follicle. In Experiment 1, 20 winter an...
Miró J, Morató R, Vilagran I, Taberner E, Bonet S, Yeste M.Three separate experiments were conducted to improve preservation of stallion epididymal sperm. In the first one, two different cooling extenders (Kenney and Gent) were compared. Sperm viability and motility patterns were assessed in 10 different epididymal sperm samples after 0 hours, 24 hours, 48 hours, 72 hours, and 96 hours of preservation at 4°C. No significant differences were observed in any of the evaluated parameters either between extenders or throughout the storage period. The second set of experiments was designed to determine whether supplementing thawing medium (INRA Freeze...
Victor S, Lampa E, Rask Andersen A, Gafvelin G, Grönlund H, Elfman L.Horse allergens are less studied than allergens from other furry animals and these allergens must be evaluated to understand the complexity of allergy to horses. The aims of this study were to develop assays for the horse allergens Equ c 1 and Equ c 2 in dander and saliva and to determine their levels in ten horse breeds. The study also included a comparison of these findings with previous results on the levels of Equ c 4 performed on the same study population. The study population included 170 horses from 10 horse breeds including American Curly and Russian Bashkir horse, which have been sugg...
Rodríguez A, Peña L, Flores JM, González M, Castaño M.This study was undertaken to investigate the presence of neuroendocrine cells (N.E.C.) by immunocytochemical means in equine lungs during three distinct evolutionary periods: fetal, neonatal and adult. The authors identified bombesin, somatostatin and calcitonin secretory cells. In the fetal lungs the N.E.C. were located in the interstitial tissue and exhibited greater immunoreactivity to bombesin than to the other two neuropeptides studied. A large number of calcitonin-producing cells and a smaller number of bombesin-positive cells were seen in the bronchial and bronchiolar epithelium of newb...
Callan MB, Giger U, Oakley DA, Scotti MV, Shofer FS.In veterinary medicine, PCV determined by centrifugation of blood in a microhematocrit tube is the most common clinical test used to initially assess and monitor anemic and polycythemic animals. In contrast, blood hemoglobin (Hb) concentration, rather than PCV, is generally determined in human patients. One automated system photometrically measures blood Hb concentration after conversion of Hb to azide methemoglobin without dilution and was found to be a simple and accurate instrument for use in human medicine. We evaluated the system for its accuracy in measuring blood Hb concentration in ani...
Cercone M, Olsen E, Perkins JD, Cheetham J, Mitchell LM, Ducharme NG.Exercise induced intermittent dorsal displacement of the soft palate (DDSP) is a common cause of airway obstruction and poor performance in racehorses. The definite etiology is still unclear, but through an experimental model, a role in the development of this condition was identified in the dysfunction of the thyro-hyoid muscles. The present study aimed to elucidate the nature of this dysfunction by investigating the spontaneous response to exercise of the thyro-hyoid muscles in racehorses with naturally occurring DDSP. Intramuscular electrodes were implanted in the thyro-hyoid muscles of nin...
Motie A.An outbreak of suspected equine infectious anaemia (EIA) among a population of 678 horses from 16 farms occurred in the Rupununi Savannahs of Guyana. Clinical signs of EIA were detected in 110 horses. Agar gel immunodiffusion (AGID) tests on 92 sera examined showed positive serological evidence of EIA in 67 (72·8%). The mean packed cell volume of 50 horses studied was 0·178
and the mean red blood cell count was 3·7 × 1012/l with the mean white blood cell count 4·1 × 109/l.
The morbidity rate of the disease was 14·0% and the mortality rate 11·1%. The majority (78%) of all seroposi...
Vimercati S, Büchi M, Zielinski J, Peduto N, Mevissen M.Cytochrome P450 enzymes (CYPs) are responsible for the phase I metabolism of drugs, xenobiotics and endogenous substances. Knowledge of single CYPs and their substrates is important for drug metabolism, helps to predict adverse effects and may prevent reduced drug efficacy in polypharmacy. In this study, three equine isoenzymes of the 3A subfamily, the equine flavoprotein NADPH-P450 oxidoreductase (POR), and the cytochrome b5 (CYB5) were cloned, sequenced and heterologously expressed in a baculovirus expression system. Testosterone, the standard compound for characterization of the human CYP3A...
Thomas HL, Livesey MA, Caswell JL.Multiple aneurysmal bone cysts (ABCs) are previously unreported in horses. An ABC was diagnosed in the left 3rd metacarpal of a Thoroughbred foal, which partially resolved following surgical curettage. A 2nd ABC developed in the left tibia, 7 wk postoperatively, and the foal was euthanized.
Neumann JL, Lazaris A, Huang YJ, Karatzas C, Ryan PL, Bagnell CA.Relaxin is a peptide hormone produced by a wide variety of mammals. In the horse, the placenta is the major source of relaxin. Since pure equine relaxin is difficult to obtain to study its role in the pregnant mare, the objectives of this study were to produce recombinant equine prorelaxin and characterize its immunological and biological activity. First, an equine relaxin gene cassette was transfected into immortalized bovine mammary epithelial (MAC-T) cells. Second, immunological activity of media conditioned by transfected MAC-T cells was tested by Western blotting and quantified using a ho...
Lansdowne JL, Kerr CL, Bouré LP, Pearce SG.To determine the relationship between epidural cranial migration and injectate volume of an isotonic solution containing dye in laterally recumbent foal cadavers and evaluate the cranial migration and dermatome analgesia of an epidural dye solution during conditions of laparoscopy in foals. Methods: 19 foal cadavers and 8 pony foals. Methods: Foal cadavers received an epidural injection of dye solution (0.05, 0.1, 0.15, or 0.2 mL/kg) containing 1.2 mg of new methylene blue (NMB)/mL of saline (0.9% NaCl) solution. Length of the dye column and number of intervertebral spaces cranial and caudal t...
Panzani S, Carluccio A, Probo M, Faustini M, Kindahl H, Veronesi MC.The aim of this study was to compare the plasma profiles of 15-ketodihydro-PGF(2α) (PGM) in healthy neonates of three different species from birth until the third week of life. Twenty-four horse foals, 12 donkey foals, and 9 calves were studied. Blood samples were collected at 10, 20 and 30 min after birth, at 3, 24 and 72 h after birth, and at 7, 10, 17 and 21 days of life. All mothers experienced normal gestation lengths and normal, spontaneous deliveries. All newborns were judged mature and viable. Hormone concentrations were higher (p < 0.05) in horse foals 20 and 30 min after birth compa...
Koenig J, Cruz A, Genovese R, Fretz P, Trostle S.The purpose of the study was to identify factors influencing the outcome and prognosis of rupture of the tendon of the peroneus tertius muscle in 27 horses. Information on history, physical examination findings, diagnosis, treatment, and final outcome was summarized from medical records. Long-term follow-up information on horses was obtained by telephone survey. A stepwise logistic regression model was used to analyze factors influencing the outcome. Rupture occurred in the midbody of the tendon in 11 horses, at the insertion site in 11 horses, and at the origin in 2 horses. Overall, 18/23 (78...
Ainsworth DM, Eicker SW, Nalevanko ME, Ducharme NG, Hackett RP, Snedden K.Horses chronically-instrumented with costal diaphragmatic electromyographic electrodes were studied during exercise while unencumbered by a breathing mask. Exercise-associated changes in esophageal (Pes), gastric (Pga) and transdiaphragmatic (Pdi) pressures were measured and related to diaphragmatic electromyographic activity (CS EMG) and to left forelimb impact. In all breaths examined, CS EMG always coincided with decrements in Pes. For all exercise trials, linear increases in CS EMG, Pga and Pdi and linear decreases in Pes, as a function of exercise intensity, always occurred. During all ga...
Linford RL.Quantitated locomotion analysis is increasingly being used during assessment and treatment of gait disorders in human beings. Locomotion analysis is also thought to have potential for enhancing the assessment of lameness in horses. Availability of high-speed video recording systems has simplified the process of quantitated locomotion analysis; however, the high cost of such systems has limited their use for routine clinical assessment in horses. The temporal resolution of 500- to 1,000-images/s (Hz) recording systems is beyond what has been considered necessary for precise quantitation of shor...
Nannarone S, Gialletti R, Veschini I, Bufalari A, Moriconi F.Alpha-2 agonists are synthetic drugs which cause sedation, analgesia and myorelaxation due to their interaction with alpha-2 adrenoreceptors, widely distributed throughout bodily systems. Because of these actions such drugs are generally used in veterinary practice: to tranquilize animals (pharmacologic restraint) for the safety of both veterinar-ians and cooperators. Such properties facilitate diagnostic examinations or minimally in-vasive and poorly painful surgical procedures, as well as limiting stress factors to the patients. The aim of this study is to find out the minor dosage able to m...
