"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
Engeli E, Haussler KK, Erb HN.Sacroiliac joint osteoarthritis has been recognised as a significant cause of poor performance in competition and racehorses. Reliable diagnostic tools are currently lacking. The diagnosis has been based typically on exclusion of other possible causes of poor performance, back pain and hindlimb lameness. Objective: To develop a safe, reliable and minimally invasive periarticular or intra-articular injection technique of potential use for diagnosis and therapy of sacroiliac joint disease in horses. Methods: Twenty-six horses were used to develop and assess a medial approach to the sacroiliac jo...
Nogueira GP.Twelve female ponies were examined daily for 30 days and classified as ovulating (OV; N = 6; 197 +/- 6 kg) or prepubertal (PP; N = 6; 196 +/- 9 kg). Follicles were detected by ultrasound and gonadotropins quantified by radioimmunoassay. The mean diameter of the largest follicles was significantly larger in OV (38 +/- 1 mm) than in PP (26 +/- 2 mm) but there was no difference between groups in the size of the second largest follicle. There were more small follicles (29 mm than the OV fillies. Follicle-stimulating hormone (FSH) levels did not differ between groups but PP fillies had lower lutein...
van der Velden MA, van der Harst MR.A literature review is given concerning the occurrence, clinical signs and possible treatment of the different types of inguinal herniation in foals. A six-week old filly with a reducible inguinal hernia is described in detail.
Lepage OM, Perron MF, Cadoré JL.Advances in the understanding of guttural pouch physiology and novel therapeutic approaches to mycotic infections in the horse are reviewed. It is suggested that the guttural pouches may contribute to the regulation of arterial blood temperature, cooling the circulation to the brain to below body temperature. Aspergillus spp. is the major organism found in a guttural pouch affected with mycosis but it is unclear why this agent becomes aggressive. Conventional therapy aims to prevent fatal haemorrhage and to treat any neurological lesions but it is desirable to try to prevent the disease. A tec...
Raeside JI, Christie HL, Renaud RL, Waelchli RO, Betteridge KJ.Because estradiol (E(2)) production by the early equine conceptus is considered crucial to the establishment of pregnancy, the amounts of E(2), estrone (E(1)), and their sulfates (E(2)S, E(1)S) were measured by RIA in yolk-sac fluid of 63 conceptuses collected by transcervical lavage over the period of 11-26 days after ovulation. Amounts increased significantly with age of conceptus, especially for E(1)S. Then, the metabolism of E(2), which may be highly relevant for its action, was examined in the conceptus and endometrium over the period when the conceptus ceases to migrate within the uterus...
Otranto D, Colwell DD, Milillo P, Di Marco V, Paradies P, Napoli C, Giannetto S.Two species of Rhinoestrus (i.e. Rhinoestrus purpureus (Brauer) and Rhinoestrus usbekistanicus Gan) cause nasal myiasis in horses, donkeys and zebras. In the past 15 years myiasis caused by R. purpureus has been reported in Egypt and by R. usbekistanicus in Senegal and Niger, both in horses and in donkeys. With the aim to investigate the presence of this myiasis in autochthonous horses and donkeys from southern Italy and to study the seasonal trend of larval infection, 212 native horses were necropsied in two slaughterhouses in the Apulia region (site A) from January to November 2003, and 120 ...
Glazar BS, McCue PM, Bruemmer JE, Squires EL.Practical estrus synchronization schemes are needed for mares. The Ovsynch synchronization protocol for cattle involves the administration of gonadotropin-releasing hormone (GnRH) to induce ovulation or luteinization of dominant follicles during the luteal phase and prostaglandin 7 days later to cause regression of any luteal tissue and development of a preovulatory follicle. An Ovsynch-type synchronization program potentially could be developed for horses if luteinization or ovulation of diestrous follicles occurred in response to GnRH treatment. The objective of this study was to determine i...
Deprez P, Vercruysse J.The results of the treatment with moxidectin or ivermectin of 20 horses with clinical cyathostominosis were studied during a 3-week observation period. Both treatments were effective in completely eliminating larvae from the faeces within 1 or 2 weeks, but no significant improvement in body weight or clinical parameters could be demonstrated over the observation period. The poor short time results of the treatment support the need for an adequate prevention of cyathostominosis in horses.
McCrory P, Turner M, Murray J.The case is reported of a retired professional jockey with progressive memory loss. The concern is that he may be suffering from chronic traumatic encephalopathy or the "punch drunk syndrome".
Dabareiner RM, Schmitz DG, Honnas CM, Carter GK.Injury to the gracilis muscle can cause acute, severe lameness in horses. Two female Quarter Horses that were used for barrel racing sustained gracilis muscle tear injuries. The site of injury was localized by direct infiltration of the area with mepivacaine. The extent of muscle tearing and seroma formation was determined via ultrasonographic evaluation. One horse developed fibrotic myopathy approximately 3 months after the original injury and underwent surgery to transect a palpable fibrous band at the previous injury site. Both horses returned to barrel racing 5 to 6 months after the injury...
Flock M, Jacobsson K, Frykberg L, Hirst TR, Franklin A, Guss B, Flock JI.Horses that have undergone infection caused by Streptococcus equi subspecies equi (strangles) were found to have significantly increased serum antibody titers against three previously characterized proteins, FNZ (cell surface-bound fibronectin binding protein), SFS (secreted fibronectin binding protein), and EAG (alpha2-macroglobulin, albumin, and immunoglobulin G [IgG] binding protein) from S. equi. To assess the protective efficacy of vaccination with these three proteins, a mouse model of equine strangles was utilized. Parts of the three recombinant proteins were used to immunize mice, eith...
Marsh AE, Lakritz J, Johnson PJ, Miller MA, Chiang YW, Chu HJ.Clinically normal horses developed cellular immunity to Sarcocystis neurona following IM vaccination with a commercial killed S. neurona vaccine, as indicated by the development of measurable anti-S. neurona IgG antibodies and additional intradermal skin testing. Large-scale independent assessments of the vaccine's performance and safety are in progress under field conditions. The next step in the evaluation of this vaccine would be to attempt experimental challenge after a reproducible reliable equine model of S. neurona encephalitis has been established that allows for reisolation of the pat...
Majewska AC, Solarczyk P, Tamang L, Graczyk TK.A total of 564 fecal specimens from 318 horses used for recreational riding, child hippotherapy, and racing at ten commercial and government-run stables in western Poland were tested for Cryptosporidium parvum oocysts by microscopic examination of Ziehl-Neelsen stained smears, enzyme immunoassay, and combined direct immunofluorescent antibody and fluorescent in situ hybridization. Also, seven stool specimens from five personnel who had repeated contact with these horses were tested for C. parvum oocysts. Eleven horses that shed C. parvum oocysts were found in five of ten stables (50%). The pre...
Alexander GR, Chester Z.To assess the effectiveness of free conjunctival grafts in the treatment of horses with a range of keratopathies. Methods: A retrospective clinical study of ten client-owned horses treated at Murdoch University Veterinary Hospital from May 1996 to September 2001. Methods: The suitability of patients for the surgical procedure was assessed using a slit lamp biomicroscope and by direct and indirect ophthalmoscopy. Surgery was performed with the aid of an operating microscope, under general anaesthesia. A subpalpebral ocular lavage catheter was used for administration of topical atropine and anti...
Pollitt CC, van Eps AW.The recommended duration of cryotherapy in horses is currently extrapolated from human medicine. Prolonged, continuous cryotherapy (days rather than minutes) may be of therapeutic value if it is safe and well tolerated. Objective: To evaluate the effect of prolonged, continuous application of ice and water to the equine distal limb. Methods: A slurry of ice and water was applied to the right forelimb of 4 Standardbred horses for 48 h. Hoof temperature, ambient temperature and ice boot temperature were logged continuously and clinical observations recorded every 2 h. Lameness examinations were ...
French KR, Pollitt CC.Acute laminitis is characterised by hoof lamellar dermal-epidermal separation at the basement membrane (BM) zone. Hoof lamellar explants cultured in vitro can also be made to separate at the basement membrane zone and investigating how this occurs may give insight into the poorly understood pathophysiology of laminitis. Objective: To investigate why glucose deprivation and metalloproteinase (MMP) activation in cultured lamellar explants leads to dermo-epidermal separation. Methods: Explants, cultured without glucose or with the MMP activator p-amino-phenol-mercuric acetate (APMA), were subject...
Pollitt CC, Daradka M.Surgical stripping of the hoof wall results in a wound that heals remarkabley well. In contrast, lamellae recovering from laminitis are often deformed. Investigating lamellar wound healing may aid understanding of laminitis. Objective: To document temporal changes in the lamellar basement membrane (BM), dermis and epidermis after surgery. Methods: Wall strips were made in the dorsal hoof wall midline of 6 mature horses. Immunohistochemistry was used to document changes in the basement membrane (BM) and detect proliferation of epidermal cells in lamellar tissues harvested at intervals. A confor...
French KR, Pollitt CC.The key lesion of laminitis is separation at the hoof lamellar dermal-epidermal interface. For this to happen the structural and adhesion proteins of the basement membrane zone must be altered. Which proteins and how damage to them leads to the lamellar separation of laminitis is unknown. Objective: To investigate lamellar hemidesmosome and cytoskeleton damage and basement membrane dysadhesion using light microscopy (LM) and immunofluorescence microscopy (IFM). Methods: Cryostat sections of lamellar tissues from 2 control and 6 Standardbred horses with oligofructose induced laminitis were stud...
Menzies-Gow NJ, Bailey SR, Katz LM, Marr CM, Elliott J.Lipopolysaccharide (LPS) infusion reduces digital perfusion, but the mediators responsible remain undetermined. Objective: To identify vasoconstrictor mediators released following LPS infusion and relate their appearance in plasma to digital blood flow alterations. Methods: Blood flow in the lateral digital vessels of 6 Thoroughbred horses, following a 30 min infusion of LPS (E. coli 055:B5; 30 ng/kg), was measured using Doppler ultrasonography. Concomitant measurements of hoof wall and coronary band surface temperatures (HWST and CBST) were made. Serial blood samples were collected and plasma...
Berhane Y, Bailey SR, Harris PA, Griffiths MJ, Elliott J.Elevated plasma homocysteine (HCy) concentration is a risk factor for cardiovascular diseases associated with endothelial dysfunction, including the human digital ischaemic disease, Raynaud's phenomenon. Objective: HCy causes dysfunction of equine vascular endothelium and elevated plasma concentrations predispose to laminitis. Objective: To determine 1) the concentration of HCy in vitro, which inhibits equine vascular endothelial cell function and 2) any association between risk of laminitis and plasma HCy concentration. Methods: Endothelial function was studied by measuring endothelium-depend...
Keen JA, McLaren M, Chandler KJ, McGorum BC.The mechanisms underlying the increased risk of laminitis in horses with equine Cushing's disease (ECD) are poorly understood. Objective: That abnormalities in glucose homeostasis, similar to those which cause microvascular dysfunction in human diabetics, contribute to development of laminitis in horses with ECD. Methods: Thirty-one aged horses were divided into 3 groups based on clinical signs and dexamethasone suppression testing (DST). Group 1 (n = 12) had clinical ECD as evidenced by hirsutism. Group 2 (n = 10) had a positive DST but no hirsutism. Group 3 (n = 9) were controls without ECD,...
McGowan CM, Frost R, Pfeiffer DU, Neiger R.Serum insulin concentration and its use as a prognostic indicator in horses with equine Cushing's syndrome (ECS) have been poorly documented. Objective: To examine daily insulin variations in horses with ECS and the effect of treatment using trilostane, a competitive inhibitor of 3beta-hydroxysteroid dehydrogenase. Further, we aimed to examine the relationship between baseline serum insulin concentration and survival in horses with ECS. Methods: Basal serum insulin concentrations were measured in 20 confirmed ECS cases by taking blood at regular 4 h intervals for 24 h (1200, 1600, 2000, 2400, ...
Bailey SR, Menzies-Gow NJ, Marr CM, Elliott J.Disturbances of digital blood flow are thought to be fundamental to the pathophysiology of acute laminitis. However, factors linking the initiating events in the equine hindgut with these disturbances in the foot remain to be determined. Objective: Amine compounds, formed by bacteria in the equine hindgut, have digital vasoconstrictor effects in vivo. Methods: Tryptamine (1.6 microg/kg/min) and phenylethylamine (2.13 microg/kg/min) were infused i.v. into standing nonsedated horses. Digital blood flow was measured by Doppler ultrasound and foot surface temperature was monitored. Plasma 5-hydrox...
van Eps AW, Pollitt CC.The hypometabolic and vasoconstrictive effects of cryotherapy could prevent the development of laminitis. Objective: To use distal limb cryotherapy to prevent laminitis induced by alimentary carbohydrate overload. Methods: Laminitis was induced in 6 Standardbred horses that had one front limb continuously cooled in an ice/water mixture. Lameness evaluation, blinded lamellar histological grading and analysis for lamellar matrix metalloproteinase-2 (MMP-2) mRNA expression were used to evaluate the severity of laminitis. Results: Cryotherapy was well tolerated and effective in cooling the feet. I...
French KR, Pollitt CC.Light microscopical studies show that the key lesion of laminitis is separation at the hoof lamellar dermal-epidermal interface. More precise knowledge of the damage occurring in the lamellar basement membrane zone may result if laminitis affected tissue is examined with the transmission electron microscope. This could lead to better understanding of the pathogenesis of lesions and the means of treatment or prevention. Objective: To investigate the ultrastructure of acute laminitis as disease of greater severity is induced by increasing oligofructose (OF) dosage. Methods: Three pairs of normal...
Daradka M, Pollitt CC.Current theories explaining how the hoof wall 'grows' and moves past the stationary distal phalanx are speculative and based on incomplete evidence. Movement in the lamellar region could occur by cell proliferation or an enzyme-based remodelling process. Since laminitis pathogenesis appears to involve increased transcription and activation of enzymes normally involved in tissue remodelling, it is important to know precisely which process dominates the lamellar region of the hoof.. Objective: To investigate epidermal cell proliferation in the equine hoof wall and calculate a proliferative index...
Waguespack RW, Kemppainen RJ, Cochran A, Lin HC, Belknap JK.The mediators and signalling cascades important in the initiation of laminitis remain unclear. We therefore wanted to explore the genes and overall signalling mechanisms that play an important role in the developmental stage of laminitis. Objective: To use a broad genomic screening technique to identify novel genes that are differentially regulated in the equine lamellae during the developmental period of laminitis. Methods: Differential mRNA display (DRD) was performed to discover regulated genes, and real-time quantitative polymerase chain reaction (RT-qPCR) was then used to evaluate lamella...
Moore RM, Eades SC, Stokes AM.To date, there is a substantial amount of data to support the hypotheses that vascular and enzymatic changes are ongoing in experimental laminitis. Furthermore, there is substantial in vitro evidence that the enzymatic changes weaken the dermo-epidermal attachments leading to mechanical failure of the hoof-bone interface of the equine digit. However, investigators of both the vascular and enzymatic theories have, to date, been unable to substantiate the effects of these pathophysiological changes in vivo on laminar tissues of horses afflicted with experimentally induced or naturally acquired l...
Elghandour MMMY, Maggiolino A, García EIC, Sánchez-Aparicio P, De Palo P, Ponce-Covarrubias JL, Pliego AB, Salem AZM.This review examines the available data regarding the positive effects of microencapsulated essential oils (EOs) on the nutrition, metabolism, and possibly the methane emission of horses. A literature review was conducted on the effect of microencapsulated (EOs) on the health of horses. The information comprises articles published in recent years in indexed journals. The results indicate that mixtures of microencapsulated EOs may be beneficial to equine health due to their antimicrobial and antioxidant activity, as well as their effects on enteric methane production, nutrient absorption, and i...
Rathbone MJ, Macmillan KL, Jöchle W, Boland MP, Inskeep EK.This paper describes the estrus cycles of a number of livestock breeds and reviews the controlled-release drug delivery systems that are currently available for the purpose of controlled breeding. The bovine estrus cycle is reviewed in detail, and the estrus cycles of other species are described in a manner that highlights similarities and differences between species. Pertinent formulation and pharmacokinetic information about current drug delivery systems is presented and discussed, and recent advances in this area are also described.
Cullen TE, Semevolos SA, Stieger-Vanegas SM, Duesterdieck-Zellmer K.This study describes clinical and ultrasonographic findings and outcomes of horses with lameness associated with muscle tears. Records of horses diagnosed with muscle tears were retrospectively evaluated. Horses in which one or more muscle tears were confirmed ultrasonographically and lameness was associated with the tear were included in the study ( = 14). Eight horses had tearing of a single muscle, 6 horses had 2 or more muscles involved. Twelve of 14 horses survived to discharge and were alive at follow-up (8 to 90 months). Recovery time ranged from 6 to 52 weeks (mean: 19.8 weeks); 6 to 1...
Conner ME, Gillespie JH, Schiff EI, Frey MS.A total of 142 equine fecal samples (93 field fecal and 49 experimental fecal specimens) were examined for rotavirus using direct electron microscopy (EM) and the Rotazyme test. Eighty-six stool specimens were diarrhea samples. The Rotazyme test sensitivity and accuracy as compared to EM was determined by the visual (color reaction) and spectrophotometric methods. The overall agreement was 94.8% and 92.3% between EM and Rotazyme visual and spectrophotometric methods, respectively when suspect reactions (1 + color reaction or net absorbance between 0.05 and 0.1) were not included. The Rotazyme ...
Kinoshita Y, Yamanaka T, Kodaira K, Niwa H, Uchida-Fujii E, Ueno T.A two-dose revaccination against tetanus is recommended for horses over 2 years old in Japan with no history of vaccination in the previous year. Here, the need for two-dose revaccination was evaluated in terms of antibody titers for each vaccine type, namely monovalent or multivalent. There was no difference in antibody titers between one- and two-dose regimens for up to 1 year, except at 8 weeks with the multivalent vaccine, and all horses had sufficient antibody titers for 1 year of tetanus prophylaxis. These results suggest that one-dose revaccination, regardless of the vaccine type, is as...
Pusterla N, Packham A, Mackie S, Kass PH, Hunyadi L, Conrad PA.Thirty-three foals from a farm with a high exposure rate to Sarcocystis neurona were assigned to either an untreated or a diclazuril-treated group. Treated foals received daily 0.5 mg/kg of diclazuril pellets from 1 to 12 months of age. Monthly blood was tested for IgG against S. neurona using the indirect fluorescent antibody test. Following ingestion of colostral antibodies to S. neurona, there was a steady and continuous decline in seroprevalence to S. neurona until foals from both groups reached weaning age. Thereafter, the untreated foal group showed a significant increase in monthly se...
Tennant B, Bettleheim P, Kaneko JJ.Chronic renal failure associated with hypercalcemia and hypophosphatemia was diagnosed in 6 horses. The renal lesions in 5 of the horses were classified as chronic glomerulonephritis and in the sixth, as chronic interstitial nephritis/pyelonephritis. There was no evidence of primary hyperparathyroidism or pseudohyperparathyroidism, thus suggesting that hypercalcemia associated with advanced renal failure in horses is related to a unique role of the equine kidney in calcium homeostasis.
Lassaline-Utter M, Cutler TJ, Michau TM, Nunnery CM.To review the signalment, clinical characteristics, and outcome of horses with nonhealing corneal ulcers treated with diamond burr debridement (DBD); and to evaluate the role of ulcer duration, size and location, and bandage contact lens (BCL) placement on healing. Methods: From January 2012-April 2013, 60 horses were diagnosed with ulcers classified as nonhealing based on the presence of raised epithelial margins and duration of at least 7 days. Methods: Retrospective record review. Results: Average age of included horses was 14.68 years, SD 8.17 years. There were three times as many males (4...
Lindsay WA, Pascoe PJ, McDonell WN, Burgess ML.Wick catheters were used to measure intracompartmental muscle pressures (ICMP) within the long heads of the triceps brachii and extensor carpi radialis muscles of 8 horses maintained under halothane anesthesia while their breathing was controlled by intermittent positive-pressure ventilation. Blood gas, cardiac output, and blood pressure determinations were monitored to maintain a stable plane of anesthesia. The horses were positioned in left lateral recumbency and were placed sequentially on each of 4 contact surfaces for 1 hour. The 4 surfaces used for each horse were concrete, foam rubber, ...
Williams DO, Boatwright RB, Rugh KS, Garner HE, Griggs DM.Studies were performed in the conscious pony instrumented with a Doppler flow probe and hydraulic occluder on the left anterior descending coronary artery (LAD), sonomicrometry crystals and intraventricular micromanometer in the left ventricle, and catheters in the left atrium and anterior interventricular vein. Two-minute LAD occlusions were performed every 30 min continuously or during working hours. Data on release of catabolites (potassium, hydrogen ions, and lactate) and norepinephrine from the initially dysfunctional region were obtained periodically during a regimen of 445 +/- 56 occlus...
Bulone V, Rademaker GJ, Pergantis S, Krogstad-Johnsen T, Smestad-Paulsen B, Thomas-Oates J.Separation of horse dander allergens using two-dimensional PAGE resulted in the identification of 16 proteins that react with allergic patient sera. A sensitive method has been developed for analysing the structures of the glycan chains of individual glycoprotein allergens transferred to blots following two-dimensional PAGE, and has allowed the structural identification of the glycan chains of the most abundant isoforms of Equ c 1, a glycosylated horse dander major allergen. The method involves separation of the allergens by two-dimensional PAGE, transfer to polyvinylidene difluoride membranes...
Pereira GR, Lorenzo PL, Carneiro GF, Bilodeau-Goeseels S, Kastelic J, Liu IK.The objectives of this study were firstly to determine whether the stimulatory function of equine growth hormone (eGH) on equine oocyte maturation in vitro is mediated via cyclic adenosine monophosphate (cAMP); and secondly if the addition of eGH in vitro influences oocyte nuclear maturation and if this effect is removed when GH inhibitors are added to the culture. Cumulus-oocyte complexes (COCs) were recovered from follicles <25 mm in diameter and randomly allocated as follows: (i) control (no additives); and (ii) 400 ng/ml of eGH. A specific inhibitor against cyclic AMP-dependent protein ...
Guan F, You Y, Li X, Robinson MA.Bioactive peptides possess pharmacological effects and can be illicitly used in sports. To deter such misuse, an untargeted method using high resolution mass spectrometry (HRMS) has been developed for comprehensive detection of multitudinous exogenous peptides in equine plasma and urine. Forty-four peptides were extracted using mixed-mode solid-phase extraction (SPE) from plasma and urine, separated with a hydrophilic interaction liquid chromatography (HILIC) column, and detected on an HRMS instrument. Ammonium formate as a mobile phase additive had effects on HILIC retention and charge state ...
Watts EJ, Rose MT.Horses are more prone to complications in the wound healing process than other species, and problems such as chronic inflammation, delayed epithelialization, poor wound contraction, and exuberant granulation tissue are commonly seen, particularly in wounds on the distal limbs. In comparison, wounds of the oral mucosa heal rapidly in a scarless fashion with a high degree of wound contraction. The effect of platelet-derived growth factor BB (PDGF), insulin-like growth factor (IGF)-1, and transforming growth factor beta1 (TGFbeta1) on the contraction of a fibroblast-populated collagen matrix (FPC...
Kędzierski W, Kusy R, Kowalik S.The aim of this study was to evaluate the relationship between plasma leptin and lipid levels in breeding mares and their newborn foals. The study was conducted on 17 Polish cold-blood mares and their newborn foals. The mares were divided into two groups, according to the course of delivery. These groups were seven mares which had a normal delivery and 10 mares which had required veterinary intervention during their delivery. Blood samples were taken from the jugular vein of both the mares and their foals. The blood samples were taken within 30 min after delivery, as well as on four successive...
Taintor J, Caldwell F, Almond G.A mare was evaluated for acute left forelimb lameness with effusion of the carpal flexor sheath. No osseous abnormalities were noted during radiographic examination. Significant disruption of the accessory ligament of the deep digital flexor tendon was seen during ultrasonographic examination. Carpal sheath effusion and lameness resolved after medical treatment. Une jument a été évaluée pour une boiterie aiguë de la patte avant gauche avec effusion de la gaine du fléchisseur carpien. Aucune anomalie osseuse n’a été observée durant l’examen radiographique. Une perturbation importa...
Suzuki Y.All types of the hemagglutinin(HA) of human, pig, horse and aq. bird influenza A viruses, recognize sialyl lacto-series type I and II sugar chains(Sialic acid(SA) alpha 2-3(6)Gal beta 1-3(4) GlcNAc beta 1-) in glycoproteins and glycolipids in the target cells as common receptor molecules. Avian and equine influenza viruses preferentially binds the terminal sialic acid alpha 2-3Gal(SA2-3Gal) linkage, while human influenza viruses preferentially bind the SA2-6Gal linkage. SA distribution in animal species influence influenza virus host range. Swine trachea has both receptors for avian influenza ...
Wagner B, Siebenkotten G, Radbruch A, Leibold W.IgE is the dominant immunoglobulin isotype involved in type I hypersensitivities in mammals. The heavy chain constant region domains of equine IgE are encoded by a single gene, the Cvarepsilon gene. By restriction analysis of cDNA from 15 unrelated horses, we have now identified two Cvarepsilon alleles, characterised by a Sma I restriction fragment length polymorphism, which we designated Cvarepsilon(a) and Cvarepsilon(b). Sequence analysis of both, Cvarepsilon(a) and Cvarepsilon(b) cDNA, showed in addition two single base exchanges resulting in two amino acid substitutions. Both sequences hav...
Woods LW, Filigenzi MS, Booth MC, Rodger LD, Arnold JS, Puschner B.Three horses died as a result of eating grass hay containing summer pheasant's eye (Adonis aestivalis L.), a plant containing cardenolides similar to oleander and foxglove. A 9-year-old thoroughbred gelding, a 20-year-old appaloosa gelding, and a 5-year-old quarter horse gelding initially presented with signs of colic 24-48 hours after first exposure to the hay. Gastrointestinal gaseous distension was the primary finding on clinical examination of all three horses. Two horses became moribund and were euthanatized 1 day after first showing clinical signs, and the third horse was euthanatized af...
Vervuert I, Coenen M, Zamhöfer J.This study was conducted to investigate the effects of draught load exercise on calcium (Ca) homeostasis in young horses. Five 2-year-old untrained Standardbred horses were studied in a 4-month training programme. All exercise workouts were performed on a treadmill at a 6% incline and with a constant draught load of 40 kg (0.44 kN). The training programme started with a standardized exercise test (SET 1; six incremental steps of 5 min duration each, first step 1.38 m/s, stepwise increase by 0.56 m/s). A training programme was then initiated which consisted of low-speed exercise sessions (LSE; ...
Giorgi M, De Vito V, Poapolathep A, Rychshanova R, Sgorbini M, Owen H.Flupirtine (FLU) is a non-opioid analgesic drug, with no antipyretic or anti-inflammatory effects, used in the treatment of a wide range of pain states in human beings. It does not induce the side effects associated with the classical drugs used as pain relievers. The aim of this study was to evaluate the pharmacokinetic profiles of FLU after IV and PO administration in healthy horses. Six mixed breed adult mares were randomly assigned to two treatment groups using an open, single-dose, two-treatment, two-phase, paired, cross-over design (2 × 2 Latin-square). Group 1 (n = 3) received ...
Lees P, Creed RF, Gerring EE, Gould PW, Humphreys DJ, Maitho TE, Michell AR, Taylor JB.Five matched pairs of horses were used to investigate the effects of phenylbutazone on a range of physiological, biochemical and haematological variables. The drug was given by mouth daily for 15 consecutive days at the manufacturer's recommended dose rates to one group of horses (Group A); the second group (Group B) received equivalent doses of a placebo. For some of the measured parameters, significant changes were recorded in both groups, indicating background instability. Significant decreases in serum total protein, albumin, plasma pH, viscosity and magnesium, and an increase in albumin: ...
Kingston JK, Bayly WM, Sellon DC, Meyers KM, Wardrop KJ.To investigate the effects of formaldehyde fixation on equine platelets using flow cytometric methods to evaluate markers of platelet activation. Methods: Blood samples from 6 Thoroughbreds. Methods: The degree of fluorescence associated with binding of fluorescein isothiocyanate (FITC)-conjugated anti-human fibrinogen antibody and FITC-annexin V in unactivated and adenosine diphosphate (ADP)-, platelet activating factor (PAF)-, and A23187-activated platelet samples in unfixed and 0.5, 1.0, and 2.0% formaldehyde-fixed samples was assessed by use of flow cytometry. Results: In samples incubated...
Smyth GB, Dagley K.To obtain information on the types of Australian horses, how they are kept and their activities. Methods: An invitation to participate in an opt-in, internet-based survey was sent to 7000 people who had registered an email address to receive information from the Australian Horse Industry Council Inc. Results: There were 3377 (48%) useable responses from owners of 26,548 horses. Most horses were kept on small properties (usually 2-8 ha) in paddocks in rural areas of Queensland, New South Wales and Victoria. Most horses were female or geldings and the most common of 54 different activities was...
Stewart AJ, Boothe DM, Cruz-Espindola C, Mitchum EJ, Springfield J.To determine the pharmacokinetics of tramadol and its metabolites O-desmethyltramadol (ODT) and N-desmethyltramadol (NDT) in adult horses. Methods: 12 mixed-breed horses. Methods: Horses received tramadol IV (5 mg/kg, over 3 minutes) and orally (10 mg/kg) with a 6-day washout period in a randomized crossover design. Serum samples were collected over 48 hours. Serum tramadol, ODT, and NDT concentrations were measured via high-performance liquid chromatography and analyzed via noncompartmental analysis. Results: Maximum mean ± SEM serum concentrations after IV administration for tramadol, ODT, ...
Magnusson LE, Ekman S.Osteoarthrosis (OA) of the antebrachiocarpal joint from 7 riding horses is described. The horses were old mares and developed severe OA, with ankylosis in some of the joints. The lesions were bilateral, and the owners noticed the lameness in a late event. The cause of severe OA in these mares is not clear. The fact that OA was bilateral indicates that a single traumatic injury is unlikely as an etiologic factor. Considering the severe joint lesions it took long time before the horse-owners noticed the lameness. It is discussed if the threshold of pain is higher in the antebrachiocarpal joint c...
Burgess BA, Lohmann KL, Blakley BR.Sudden deaths and an outbreak of diarrhea in horses occurred in southern Saskatchewan in 2006. Five horses died while survivors presented with diarrhea and, in 1 case, acute neurologic signs attributed to hyponatremia. Diagnostic testing of affected horses and environmental testing suggested poor water quality, specifically high salinity and high sulfate concentration as the cause. Des morts soudaines et une éclosion de diarrhée se sont produites chez des chevaux du Sud de la Saskatchewan en 2006. Cinq chevaux sont morts tandis que les survivants ont présenté de la diarrhée et, dans 1 ca...
