Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Brown MP, West LA, Merritt KA, Plaas AH.To determine effects of aging on sulfation of chondroitin sulfate (CS) in articular cartilage and synovial fluid from normal equine middle carpal joints, and to determine whether CS compositional analysis can be used to assess alterations in proteoglycan turnover in degenerative cartilage obtained from horses with carpal osteochondral fractures. Methods: Carpal articular cartilage and synovial fluid from 44 cadavers with normal joints and from 16 Thoroughbred racehorses during routine carpal arthroscopic surgery. Methods: After papain/chondroitinase digestion of cartilage, CS disaccharides (un...
Howard RD, McIlwraith CW, Trotter GW, Nyborg JK.To clone equine interleukin 1 alpha (IL-1 alpha) and equine interleukin 1 beta (IL-1 beta) and determine their full-length cDNA sequences. Methods: The mRNA isolated from lipopolysaccharide-stimulated cultured equine monocytes was reverse transcribed, and a cDNA library was constructed in a lambda phage. The cDNA library was screened by means of plaque hybridization with radiolabeled human IL-1 alpha and IL-1 beta cDNA probes. The cDNA nucleotide sequences for equine IL-1 alpha and equine IL-1 beta were determined by use of the dideoxy chain termination technique. The cDNA sequences were analy...
Gérard N, Monget P.The profiles of insulin-like growth factor-binding proteins (IGFBPs) in follicular fluid have been characterized in a number of mammals (rats, pigs, sheep, cattle, humans) and are good indicators of follicular status. We studied the IGFBP profiles of equine serum and ovarian follicular fluid recovered at various stages of the follicular phase. The levels of IGFBPs were related to the morphology and the steroidogenic activity of the follicles. Follicular fluids were recovered by ultrasound-guided follicular aspiration. In the first experiment, the dominant follicles of 10 mares were partly punc...
Brink P, DeGraves F, Ravis WR, Johansen D, Campbell JD, Duran SH.To determine intravascular and intrasynovial pharmacokinetics of the R and S enantiomers of ketoprofen after i.v. and i.m. administration to horses. Methods: 6 healthy adult mares. Methods: Horses were weighed and ketoprofen (2.2 mg/kg of body weight) was administered i.v. Blood and synovial fluid samples were obtained and analyzed for concentrations of the R and S enantiomers by means of a modified reverse-phase stereospecific high-pressure liquid chromatographic method. Three weeks later, the procedure was repeated, except that ketoprofen was given IM. Protein binding of ketoprofen enantiome...
Barton MH, Bruce EH, Moore JN, Norton N, Anders B, Morris DD.To test efficacy of murine monoclonal, rabbit polyclonal recombinant equine or human tumor necrosis factor-alpha (rETNF or rHTNF, respectively) antibodies to inhibit native equine tumor necrosis factor (TNF) activity. Methods: 8 and 18 healthy adult horses for parts 1 and 2 of the study, respectively. Methods: In part 1, supernates from endotoxin-activated peritoneal macrophages were incubated with various dilutions of each rETNF antibody and subsequently tested for TNF activity. Serum was also obtained from a horse 1 hour after infusion with 20 ng of endotoxin/kg of body weight and was incuba...
East LM, Savage CJ, Traub-Dargatz JL, Dickinson CE, Ellis RP.To identify clinical signs, physical examination findings, results of diagnostic tests, treatments administered, and clinical outcome of neonatal foals with enterocolitis associated with Clostridium perfringens infection. Methods: Retrospective study. Methods: 54 neonatal foals. Results: Most foals had acute onset of obtunded mentation, colic, or diarrhea and developed leukopenia, neutropenia, an abnormally high number of band neutrophils, toxic WBC, and hypoproteinemia within 24 hours after admission, despite high serum IgG concentrations (> 800 mg/dl). Abdominocentesis and abdominal radiogra...
Geor RJ, McCutcheon LJ.This study examined the effects of hyperhydration, exercise-induced dehydration, and oral fluid replacement on physiological strain of horses during exercise-heat stress. On three occasions, six horses completed a 90-min exercise protocol (50% maximal O2 uptake, 34.5 degrees C, 48% relative humidity) divided into two 45-min periods (exercise I and exercise II) with a 15-min recovery between exercise bouts. In random order, horses received no fluid (NF), 10 liters of water (W), or a carbohydrate-electrolyte solution (CE) 2 h before exercise and between exercise bouts. Compared with NF, preexerc...
Manohar M, Goetz TE.The present study was carried out to examine the effects of nitric oxide synthase inhibition with Nomega-nitro-L-arginine methyl ester (L-NAME) on the right atrial as well as on the pulmonary arterial, capillary, and venous blood pressures of horses during rest and exercise performed at maximal heart rate (HRmax). Experiments were carried out on seven healthy, sound, exercise-trained Thoroughbred horses. Using catheter-tip manometers, with signals referenced at the point of the shoulder, we determined phasic and mean right atrial and pulmonary vascular pressures in two sets of experiments [con...
Thamsborg SM, Leifsson PS, Grøndahl C, Larsen M, Nansen P.Twelve Standardbred foals (age 3-6 months), with little previous exposure to parasites, were allocated to 2 groups and put onto pasture with low (Group L) or high (Group H) levels of larval contamination of large strongyles and cyathostomes. After 4 weeks grazing in September, the foals were housed indoors until necropsy 15 weeks later. Foals in Group H became clinically more affected than those of Group L in that they showed loss of vigour, weight gain depression, intermittent soft faeces and inappetence. One foal of Group H had persistent diarrhoea and was subjected to euthanasia 12 weeks af...
Pearce SG, Firth EC, Grace ND, Fennessy PF.The effect of copper status on the evidence of bone and cartilage lesions was investigated in 21 Thoroughbred foals. The foals and their dams were grazed on pasture containing 4.4-8.6 mg Cu/kg dry matter (DM). Four treatment groups were created by randomly allocating mares and their foals to either copper supplemented (0.5 mg Cu/kg liveweight (LW)/day), or control (pasture only) groups. This experimental design allowed the effect of copper supplementation of mare and foal to be examined independently. Parameters of bone and cartilage development were assessed in the foals both in vivo, and at ...
Parente EJ, Martin BB, Tulleners EP.Many disorders of the upper respiratory tract which cause severe
respiratory compromise and poor performance have been
described in the equine athlete (Williams et al. 1990; Morris 1991;
King et al. 1994). Until recently, the diagnosis of upper respiratory
tract dysfunction was based on observations made during resting
endoscopic examination; and conclusions regarding the extent and
exact nature of the dysfunction during exercise were often
inaccurate. This report describes 2 horses presented to the George
D. Widener Hospital in which no significant abnormalities were
noted during res...
Pearce SG, Grace ND, Firth EC, Wichtel JJ, Holle SA, Fennessy PF.The effect of copper supplementation of pasture fed mares and foals on the copper status of the foals, in terms of plasma, soft tissue and bone copper concentrations and caeruloplasmin activity, was investigated. Twenty-one Thoroughbred foals from either control mares (n = 9), or copper-supplemented mares (n = 12) were divided randomly into control (pasture only, n = 10) or supplemented (pasture and oral copper sulphate, n = 11) groups. The pasture diet was grazed by all animals, and contained 4.4-8.6 mg Cu/kg dry matter (DM). The copper supplement for the mares contained copper sulphate equiv...
Rijkenhuizen AB, van Swieten HA.A surgical technique is described in which a saphenous vein graft is used to reconstruct the jugular vein in horses with facial oedema due to post thrombophlebitic stenosis of the jugular vein. The saphenous vein was harvested from the contralateral limb and implanted in the occluded vein by 2 side-to-end anastomoses. Intra- and post operatively anticoagulative medication was administered. In 2 out of 3 patients the reconstruction resulted in a permanent patent graft and resolution of the facial oedema. In one patient the graft thrombosed.
Proudman CJ, French NP, Trees AJ.The association between the equine intestinal tapeworm Anoplocephala perfoliata and specific types of intestinal disease was investigated by matched case-control study using coprological and serological diagnosis. We have previously shown that the host IgG(T) response to 12/13 kDa antigens of A. perfoliata correlates well with infection intensity, therefore this antibody response was used to investigate the risk of colic at different levels of parasite infection intensity. One hundred and three spasmodic colic cases with an equal number of controls matched for age, breed and gender, and 20 ile...
Pearce SG, Grace ND, Wichtel JJ, Firth EC, Fennessy PF.Pregnant Thoroughbred mares (n = 21) were grazed on tall fescue pasture containing 4.4-8.6 mg Cu/kg dry matter (DM). Twelve mares were supplemented with approximately 0.5 mg Cu/kg liveweight (LW)/day as copper sulphate for the final 13-25 weeks gestation. Plasma copper concentration declined during the third trimester for all mares and was not affected by copper supplementation. Liver copper concentration of mares and foals was determined when the foals were 4-10-days-old. Copper supplementation of the mares tended to increase mare liver copper concentration (P<0.08) and increased foal live...
Weber Polack E, King JM, Cummings JF, de Lahunta A, Divers TJ, Mohammed HO.The mean number of motor neurons was assessed in the C7 spinal cord segment of 5 EMND and 5 control horses. Mean number per section in EMND horses was reduced significantly (P<0.001). The mean neuronal loss was estimated at 31%. Each of the 5 affected horses had a mean neuronal count below the 95% confidence interval for control horses. The statistically significant difference between the 2 groups was consistent in the cranial, middle and caudal thirds of the C7 segment (P<0.001). The results of regression analysis indicated an association between neuronal reduction in EMND horses and th...
Cheung TK, Warren LK, Lawrence LM, Thompson KN.Surface electrodes were used to record electromyographic (EMG) activity of the long digital extensor muscle on the right hindlimb of 8 Thoroughbred horses for 8 s at the walk and 8 s at the trot before (unfatigued) and after (fatigued) an exercise test. The exercise test was performed on a motorised treadmill set on a 10% grade. Each test started at a speed of 6 m/s which was increased by 1 m/s each minute until the horse fatigued as indicated by its inability to keep pace with the treadmill with minimal encouragement. Observations were made on the horses prior to conditioning (untrained state...
Potard US, Leith DE, Fedde MR.Thoroughbred (TB) and draft horses (DH) have long been selected for tasks of very different intensities and force-speed relationships. To study their adaptations, we measured O2 consumption and related variables in three TB and four DH during progressive exercise tests on a level treadmill. The horses exerted a draft force of 0, 5, 10, 15, or 20% of their body weight at speeds that increased by 2 m/s every 3 min until they could not maintain that speed. We found that TB could exert the same draft forces as DH and, at each force, TB achieved about twice the speed, twice the external power, and ...
Chaffin MK, Cohen ND.To determine whether administration of commercially available Escherichia coli antiserum to neonatal foals would affect serum IgG concentration or morbidity and mortality rates during the first 60 days of life. Methods: Randomized controlled trial. Methods: 271 neonatal foals on 4 well-managed farms. Methods: Foals were randomly assigned to a treatment or control group. All foals were allowed to suckle colostrum normally. In addition, treatment-group foals were given E coli antiserum (10 micromilligrams) orally between 0 and 8 hours after birth. Serum samples were obtained between 18 and 36 ho...
Wright IM, Kidd L, Thorp BH.Forelimb navicular bones and associated soft tissues were collected from 3 groups of horses and subjected to pathological examinations. The groups consisted of 38 horses with clinical navicular disease (ND) and 2 control groups, with no history of forelimb lameness, consisting of 25 age-matched mature horses (A-MC) and 9 immature horses (IC). Histological and histomorphometric studies were performed on tissue samples from 10 ND, 10 A-MC and 5 IC horses. Gross changes seen only in ND horses included: full thickness defects in the palmar surface fibrocartilage, palmar cortex erosion, medullary l...
Hinchcliff KW, McKeever KH.The effect of blood volume repletion after frusemide administration on the right atrial and pulmonary artery pressure responses of horses to exercise has not been reported. We examined right atrial and pulmonary artery pressure and plasma atrial natriuretic peptide concentration (ANP) responses to an incremental exercise test in 6 Standardbred mares. Horses were treated, in a 3 way cross over design, with isotonic saline, frusemide (1 mg/kg bwt, i.v.), and frusemide followed 3 h later by lactated Ringer's solution (12 ml/kg bwt, i.v.). Three and a half hours after saline or frusemide administr...
Les CM, Stover SM, Taylor KT, Keyak JH, Willits NH.The objective of this study was to examine several simple ex vivo loading conditions for the equine metacarpus, and to evaluate their ability to reproduce the mid-diaphyseal bone surface strain distributions previously reported in vivo at the walk and trot. Distributed axial compressive loads, and 9 different axial compressive point loads at -7.5 kN and -15 kN were applied to metacarpal-distal carpal bone preparations from 6 Thoroughbred horses, aged 1-5 years. The resulting dorsal, medial, palmar, and lateral mid-diaphyseal bone surface axial and shear strains were compared with previously re...
Rawlings P, Snow WF, Boorman J, Denison E, Hamblin C, Mellor PS.Twelve light trap collections made near overnight shelters of horses and donkeys in four villages in the Central River Division of The Gambia captured fourteen species of biting midge of the genus Culicoides. Five species new to The Gambia were identified. This brought the number of recognized species of Culicoides (after a revision of C. schultzei) to twenty-nine in The Gambia. Species known or suspected as vectors of African horse sickness virus (AHSV) and bluetongue virus (BTV) comprised 83% of female captures, 65% of captures being C. imicola or its sibling species, C. miombo. Captures of ...
Marteniuk JV, Carleton CL, Lloyd JW, Shea ME.To determine whether sex of fetus, sire, month of conception, or year of foaling was associated with duration of gestation in mares. Methods: Epidemiologic retrospective cohort study. Methods: 500 foalings for 296 Standardbred mares. Methods: Data for reproductive events from 1986 to 1992 were analyzed. Analyses were conducted to determine whether duration of gestation was associated with sex of fetus, sire, month of conception, or year of foaling. Results: Mean duration of gestation was 343.3 days and was significantly greater for colt fetuses (344.4 days) than for filly fetuses (342.2 days)....
Bassage LH, Richardson DW.To determine type, distribution, and radiographic appearance of condylar fractures of the third metacarpal bone (MC-3) or third metatarsal bone (MT-3) in Thoroughbreds (TB), Standardbreds (SB), and Arabians, to assess long-term outcome of horses in which fractures were repaired surgically, and to identify variables associated with prognosis for return to racing. Methods: Retrospective study. Methods: 224 horses with 233 fractures. Methods: Medical records and radiographs obtained before and after treatment were reviewed. Racing performance before and after treatment was determined by reviewing...
Reubel GH, Barlough JE, Madigan JE.We report on the production and characterization of Ehrlichia risticii, the agent of Potomac horse fever (PHF), from snails (Pleuroceridae: Juga spp.) maintained in aquarium culture and compare it genetically to equine strains. Snails were collected from stream waters on a pasture in Siskiyou County, Calif., where PHF is enzootic and were maintained for several weeks in freshwater aquaria in the laboratory. Upon exposure to temperatures above 22 degrees C the snails released trematode cercariae tentatively identified as virgulate cercariae. Fragments of three different genes (genes for 16S rRN...
Lakritz J, Wilson WD, Marsh AE, Mihalyi JE.To determine effects of prior feeding on pharmacokinetics and estimated bioavailability of orally administered microencapsulated erythromycin base (MEB) in healthy foals. Methods: 6 healthy foals, 3 to 5 months old. Methods: Foals were given 2 doses of MEB (25 mg/kg of body weight, PO). One dose was administered after food was withheld overnight, and the other was administered after foals had consumed hay. The study used a crossover design with a 2-week period between doses. Blood was collected via a jugular vein prior to and at specific times after drug administration. Concentrations of eryth...
Lopes-Pereira CM, Harun M, Schmidtova D, Timane I, Mabasso M, Otto F, Bogin E.Adapting the concept of "bed-side" patient analysis, the Boehringer-Mannheim Reflotron was evaluated for its possible use in veterinary medicine under outdoor-field conditions. Horse blood was analysed with the Cobas Bio analyzer, and indoor and outdoor analyses were also performed with the Reflotron. All values showed close agreement with no significant differences. Good correlation coefficients (r values around 0.9000) were also seen between all methods used. The Reflotron was operated under outdoor-field conditions by using, whenever available, an on-farm electricity source, or a gas operat...
Steel CM, Bolton JR, Preechagoon Y, Charles BG.The purpose of this study was to determine the pharmacokinetics and absolute bioavailability of cisapride after intravenous (i.v.) and intragastric (i.g.) administration in healthy, adult horses. Five animals received single doses of 0.1 mg/kg, 0.2 mg/kg and 0.4 mg/kg cisapride by the i.g. route in an open, randomized fashion on different occasions separated by a washout period of at least 48 h. Four of these horses were also given a single i.v. dose of 0.1 mg/kg cisapride. Jugular venous blood was collected periodically up to 24 h after dosing. Plasma cisapride concentrations were measured by...
Jenei TM, García-López JM, Provost PJ, Kirker-Head CA.To determine prevalence, clinical findings, and long-term survival rate after surgery associated with incarceration of the small intestine through the gastrosplenic ligament (ISIGL) in horses. Methods: Retrospective case series. Methods: 14 horses with ISIGL. Methods: Medical records of horses with ISIGL examined between January 1994 and December 2006 were reviewed. Signalment, initial physical examination findings, results of abdominal fluid analysis, and clinical laboratory values were recorded, along with surgical findings, including segment of incarcerated intestine and surgical procedures...
Williams JW, Meagher DM, Pascoe JR, Hornof WJ.Upper airway pressure was measured during maximal exercise in 10 Thoroughbred racehorses with naturally occurring upper airway obstruction. Left laryngeal hemiplegia and arytenoid chondropathy resulted in substantial increases (30-40 cm H2O) in inspiratory upper airway pressure (Pl), whereas complicated aryepiglottic entrapment and subepiglottic cysts produced only modest increases (15 cm H2O) in Pl. Uncomplicated aryepiglottic entrapment and grade IV pharyngeal lymphoid hyperplasia produced only slight increases (3-5 cm H2O). In general, surgical procedures restored airway pressures to within...
Baeyens WR, Van der Weken G, Haustraete J, Aboul-Enein HY, Corveleyn S, Remon JP, García-Campaña AM, Deprez P.The group of LiChrospher ADS (alkyl-diol silica) sorbents that make part of a unique family of restricted-access materials, have been developed as special packings for precolumns used in the LC-integrated sample processing of biofluids. The advantage of these sorbents lies in the direct injection of untreated biological fluids, that is without sample clean-up, the elimination of the protein matrix with a quantitative recovery together with an on-column enrichment. The present method is based on previous work applying UV detection at 260 nm for ketoprofen determinations. Plasma samples introduc...
Franklin SH, Barakzai SZ, Couroucé-Malblanc A, Dixon P, Nankervis KJ, Perkins JD, Roberts CA, Vanerck-Westergren E, Allen KJ.During the past 20 years, treadmill exercise testing has played an important role in both the study of equine exercise physiology and the investigation of poor athletic performance. However, it has been suggested that some trainers and veterinarians may be reluctant to refer horses for treadmill exercise testing because of fears that horses may be at increased risk of musculoskeletal injury during treadmill exercise. Objective: To investigate the incidence and types of injuries sustained by horses undergoing treadmill exercise. Methods: Data were collated from 9 centres in the UK, France and B...
Imai S, Ozeki K, Fujita J.The surface structure of the ciliary zone in 13 species of ciliates found in the large intestine of the horse was observed by scanning electron microscopy. In Holophryoides ovalis many fine depressions considered to be a result of phagocytosis or pinocytosis in the naked cytostome were noticed. In Blepharocorys spp. a distinct section was present between the portion with cilia and that without cilia. It was not present, however, in some species of the family Buetschliidae, such as Bundleia postciliata and Didesmis spp. The species of Entodiniomorphida had a lip around the ciliary zone with cil...
Munsterman AS, Gillen AM, Coleridge MOD, Hanson RR.To evaluate the effect of changes in intra-abdominal pressure (IAP) on medial saphenous venous pressure (MSVP) and hemodynamics in normal horses. Methods: Experimental, in-vivo study. Methods: University Teaching Hospital. Methods: Convenience sample of 7 mixed breed horses; 5 geldings, and 2 mares. Methods: Pneumoperitoneum was induced in horses under standing sedation with carbon dioxide gas using a laparoscopic insufflator for a total of 60 minutes to simulate clinical elevation in IAP. Pressure was increased stepwise to 20 mm Hg over 30 minutes, and maintained at that pressure for 30 minu...
Smith BL, Auer JA, Watkins JP.Four horses, 2 to 17 years old, were treated for unilateral avulsion fractures of the tibial tuberosity. Two horses were treated successfully with tension band wiring or plating in combination with lag screw fixation. One horse was euthanatized because of implant failure during recovery and one was euthanatized on day 11 because a longitudinal fracture of the tibial tuberosity occurred through the plane of the screws used for stabilization.
Mills JS, Kinsley MA, Peters DF, Weber PSD, Shearer TR, Pease AP.The purpose of this study was to determine whether there was a correlation between circulating and intra-synovial Dkk-1 and radiographic signs of equine osteoarthritis. Methods: Circulating and intra-synovial Dkk-1 levels were measured in clinical cases using a commercially available human Dkk-1 ELISA. Radiographs were performed of the joints from which fluid was collected and these were assessed and scored by a boarded radiologist for joint narrowing, subchondral bone sclerosis, subchondral bone lysis, and periarticular modelling. Comparisons were made between radiographic scores and the conc...
Matthews NS, Hartsfield SM, Sanders EA, Light GS, Walker MA.A 27-year-old horse was anesthetized 3 times a week for 4 weeks, to facilitate cobalt therapy of a squamous cell carcinoma in the left paranasal sinus. Limitations of facilities required transport of the anesthetized horse to and from the cobalt therapy room, therefore, injectable anesthesia was used. Initially, the horse was preanesthetized with xylazine (at 1.1 mg/kg IV) and butorphanol (0.04 mg/kg IV). After 3 anesthetic episodes, the xylazine dose was reduced to 0.4 mg/kg IV and the butorphanol was deleted from the regimen. Tiletamine-zolazepam (1.1 mg/kg IV) was used for induction and mai...
Carmalt JL, Allen AL.To evaluate the effect of rostrocaudal mobility (RCM) of the mandible during extension and flexion of the atlanto-occipital joint on weight gain, feed digestibility, and fecal particle size in horses. Methods: Randomized controlled trial. Methods: 34 pregnant mares housed in 1 barn. Methods: Horses were randomized into a treatment (n = 17) or control (17) group. All horses were sedated, and the distance between the rostral portions of the upper and lower incisor arcades was determined during extension and flexion of the atlanto-occipital joint; mandibular RCM was calculated as the difference b...
Voith VL.This article discusses some general principles of learning as well as possible constraints and how such principles can apply to horses. A brief review is presented of experiments that were designed to assess learning in horses. The use of behavior modification techniques to treat behavior problems in horses is discussed and several examples of the use of these techniques are provided.
Velde K, Ross MW, Orsini JA, Parente EJ, Foley B, Richardson DW, Miselis RR.To study the fascicular anatomy of peripheral nerves, three different groups of retrograde axonal tracers were evaluated: fluorophores, horseradish peroxidase conjugated to subunit B of cholera toxin (CT-HRP), and adeno-associated virus (AAV). The hindlimb nerves in rats served as a model to identify the most efficient tracer in regard to labeling axons within peripheral nerves. The rat's tibial and common peroneal nerves were injected with the different tracers and the sciatic nerve was subsequently examined for evidence of labeled axons. The CT-HRP clearly provided the best results in this r...
Bracamonte JL, Devick I, Thomas KL, Hendrick S.The objective of this study was to compare the biomechanical properties of hand-sewn jejunojejunal anastomoses to those of oversewn stapled jejunojejunal anastomoses. Jejunojejunal anastomoses were constructed from harvested jejunal segments using a single-layer Lembert technique (1HS), double-layer simple continuous/Cushing technique (2HS), stapled side-to-side technique oversewn with Cushing pattern (SS), and closed 1-stage stapled functional end-to-end technique oversewn with Cushing pattern (FEE). Anastomosed segments were distended with fluid until the point of biomechanical failure. The ...
Arthur GH.The effect of intrauterine saline on reproductive function was studied by infusion of mares in anoestrus, dioestrus, oestrus and prolonged dioestrus. Anoestrous mares were unaffected except near the beginning and end of the breeding season when anovulatory heats were induced. Dioestrous mares infused between Days 5 and 9 returned to heat an average of 3-8 days earlier than expected, and infusions during dioestrus were followed by ovulatory heats of normal fertility. Three mares in prolonged dioestrus showed ovulatory heats within 3 to 9 days of infusion. Infusions during oestrus had no appreci...
Nieto JE, Morales B, Yamout SZ, Stanley SD, Harmon FA, Snyder JR.To determine the response to neostigmine of the contractile activity of the jejunum and pelvic flexure and the effects of a continuous rate infusion (CRI) of neostigmine in horses. Methods: 7 adult horses and tissue from 12 adult horses. Methods: A CRI of neostigmine (0.008 mg/kg/h) or placebo was administered to 6 horses in a crossover study design. Gastric emptying was evaluated by the acetaminophen test. The frequency of defecation and urination and the consistency and weight of feces were recorded throughout the experiment. The effect of neostigmine on smooth muscle contractile activity wa...
Taylor P, Scarth JP, Hillyer LL.Within equine drug surveillance, there is significant interest in analyzing intact phase II conjugates of drugs in urine, but progress has been limited by a lack of reference material. Methods: In this study, in vitro techniques using equine liver fractions were employed to produce glucuronide and sulfate conjugates of stanozolol, 16β-hydroxystanozolol and nandrolone, the glucuronide conjugate of morphine and the glutathione metabolite of chlordinitrobenzene for the first time in equine sports drug surveillance. Results: The glucuronide conjugate of the synthetic progestagen altrenogest was a...
Schwarz B, Burford J, Knottenbelt D.This case report describes a 4-year-old-horse with two cutaneous masses on the right crest of the neck. Biopsy revealed chronic nodular pyogranulomatous dermatitis and panniculitis. Giemsa and periodic acid-Schiff stains showed focal spherical, yeast-like organisms. A diagnosis of cutaneous fungal granuloma was made. The size of the masses decreased after oral treatment with fluconazole for 10 days combined with potassium iodide for 30 days, and the remaining masses were excised by laser. Lesions did not recur at the site. Fungal granuloma should be considered as a differential diagnosis in ho...
Roberts MC, Kelly WR.Granulomatous enteritis was diagnosed in a 4-year-old Standarbred mare suffering from chronic weight loss, depression, dependent oedema but not diarrhoea. There was hypoproteinaemia (hypoalbuminaemia), lymphocytopaenia and neglibible carbohydrate absorption from the small intestine. Pathological changes in almost the entire small intestine included proprial infiltration resulting in partial villous atrophy, and granuloma formation beneath the muscularis which was most severe in the ileum. Slight infiltration occurred in the stomach and the colon. The cells were predominantly lymphocytes and hi...
Tremaine H.The last decade has seen a number of studies that have illuminated our knowledge of hypsodont dental disease and re-examined some of the traditionally performed practices. In addition there has been a major interest in routine preventative dentistry and non-traumatic treatments. These have highlighted some potential risks of the use of modern tools when applied to traditional techniques. This has also led to a reflective review of equine dentistry with the emphasis on attempting to preserve and salvage dental and periodontal tissues, with minimal trauma. In addition, precise imaging and instru...
Vanderstock JM, Lecours MP, Lavoie-Lamoureux A, Gottschalk M, Segura M, Lavoie JP, Jean D.OBJECTIVE To evaluate in vitro phagocytosis and bactericidal activity of circulating blood neutrophils in horses with severe equine asthma and control horses and to determine whether circulating blood neutrophils in horses with severe equine asthma have an increase in expression of the proinflammatory cytokine tumor necrosis factor (TNF)-α and the chemokine interleukin (IL)-8 and a decrease in expression of the anti-inflammatory cytokine IL-10 in response to bacteria. ANIMALS 6 horses with severe equine asthma and 6 control horses. PROCEDURES Circulating blood neutrophils were isolated from h...
Ross MW, Martin BB.Seven Standardbred horses, all pacers, with a mean age of 2.9 years (range, 2 to 4 years), had dorsomedial articular fracture of the proximal aspect of the third metacarpal bone. Fracture caused acute, unilateral, severe lameness after training or racing. Lameness was abolished by midcarpal joint anesthesia in 4 horses. Six horses had a palpable bony swelling, which caused signs of pain. Radiography revealed a nondisplaced, articular, oblique fracture extending distad toward the dorsomedial cortex for a mean distance of 28 mm (range, 15 to 40 mm). In all horses, chronic periosteal proliferativ...