Gastrointestinal health in horses encompasses the study of the structure, function, and disorders of the equine digestive system. The equine gastrointestinal tract is complex, consisting of the stomach, small intestine, cecum, and large intestine, each playing a specific role in digestion and nutrient absorption. Research in this area often focuses on common disorders such as colic, gastric ulcers, and parasitic infections, which can impact a horse's overall health and performance. Investigations examine factors affecting gastrointestinal health, including diet, management practices, and the microbiome. This page compiles peer-reviewed research studies and scholarly articles that explore the physiology, pathology, and management of gastrointestinal health in horses.
MacNicol JL, Pearson W. organ culture can provide insight into isolated mucosal responses to particular environmental stimuli. The objective of the present study was to investigate the impact of a prolonged culturing time as well as the addition of acidic gastric fluid into the environment of cultured gastric antral tissue to evaluate how altering the commonly used neutral environment impacted tissue. Furthermore, we aimed to investigate the impact of G's Formula, a dietary supplement for horses, on the secretion of gastrin, interleukin1-beta (IL-1β), and nitric oxide (NO). These biomarkers are of interest due to ...
Lo Feudo CM, Stucchi L, Conturba B, Alberti E, Zucca E, Ferrucci F.Equine squamous gastric disease (ESGD) may require prolonged treatments with acid suppressants; therefore, interest in nutraceutical supplements with anti-ulcerogenic properties has increased. This study aims to investigate the efficacy of Trophogast pellet for the treatment of ESGD in endurance horses. Methods: Fifteen endurance horses were included based on their gastroscopic examination and randomly assigned to a treatment group, receiving Trophogast pellet for 30 days together with management changes, or to a control group, only subjected to management modifications. At the end of treatmen...
Raspa F, Dinardo FR, Vervuert I, Bergero D, Bottero MT, Pattono D, Dalmasso A, Vinassa M, Valvassori E, Bruno E, De Palo P, Valle E.Horses reared for meat production are fed high amounts of cereal grains in comparison with horses raised for other purposes. Such feeding practice may lead to risk of poor welfare consequences. The aim of this study was to investigate the effects of two feeding practices on selected metabolic parameters and production aspects. Nineteen Bardigiano horses, 14.3 ± 0.7 months of age, were randomly assigned to two groups-one fed with high amounts of cereal grains (HCG; n = 9; 43% hay plus 57% cereal grain-based pelleted feed) vs. one fed with high amounts of fibre (HFG; n = 10; 70% hay plus...
Hector RC, Rezende ML, Nelson BB, Monnet E.Endotoxaemia causes untoward inflammatory-mediated effects that might be attenuated by dexmedetomidine. Objective: To evaluate the effects of a dexmedetomidine intravenous (IV) infusion on systemic and intestinal haemodynamics and arterial blood gas values in sevoflurane-anaesthetised horses administered Escherichia coli O55:B5 lipopolysaccharides (LPS). Methods: Randomised controlled in vivo experiment. Methods: A total of 13 horses weighing 456 ± 86 kg (mean ± standard deviation) and aged 13.9 ± 9.0 years donated for euthanasia underwent ventral midline celiotomy using sevoflurane...
Fernandes KA, Rogers CW, Gee EK, Kittelmann S, Bolwell CF, Bermingham EN, Biggs PJ, Thomas DG.The management of competition horses in New Zealand often involves rotations of short periods of stall confinement and concentrate feeding, with periods of time at pasture. Under these systems, horses may undergo abrupt dietary changes, with the incorporation of grains or concentrate feeds to the diet to meet performance needs, or sudden changes in the type of forage fed in response to a lack of fresh or conserved forage. Abrupt changes in dietary management are a risk factor for gastrointestinal (GI) disturbances, potentially due to the negative effects observed on the population of GI microb...
Lindroth KM, Lindberg JE, Johansen A, Müller CE.Free faecal liquid (FFL) in horses is characterised by the excretion of faeces in two phases (one solid and one liquid), which may cause dermatitis on the hindlegs. The causes of FFL are not known. Results from previous studies have indicated that feed ration composition and management factors may play important roles in the occurrence of FFL. A case-control study was therefore performed in which data on feed rations, feeding practices and management factors were compared between horses with (case) and without (control) FFL on 50 private farms in Sweden and Norway. The comparisons show that ca...
Hellman S.Enteroid cultures are three-dimensional in vitro models that reflect the cellular composition and architecture of the small intestine. One limitation with the enteroid conformation is the enclosed lumen, making it difficult to expose the apical surface of the epithelium to experimental treatments. The present study was therefore conducted to generate cultures of equine enteroids and to develop methods for culture of enteroid-derived cells on a two-dimensional plane, enabling easy access to the apical surface of the epithelium. Equine enteroids were established from small intestinal crypts with...
Bachmann M, Glatter M, Bochnia M, Greef JM, Breves G, Zeyner A.For a period of 20 days, 12 horses either received a prebiotic supplementation with fructooligosaccharides and inulin via Jerusalem artichoke meal (JAM) or corncob meal without grains (CMG) as placebo. The horses were euthanized 1 hour postprandial, gastric digesta was sampled from pars nonglandularis (PNG) and pars glandularis (PG), and concentrations of starch, mono- and disaccharides, fructans, d- and l-lactic acid, and short chain fatty acids were analyzed. Concentrations of starch and simple sugars were widely the same in JAM supplemented and not supplemented meals. However, fructans were...
Ghafar A, Abbas G, King J, Jacobson C, Hughes KJ, El-Hage C, Beasley A, Bauquier J, Wilkes EJA, Hurley J, Cudmore L, Carrigan P, Tennent-Brown B....Faecal egg counting techniques (FECT) form the cornerstone for the detection of gastrointestinal parasites in equines. For this purpose, several flotation, centrifugation, image- and artificial intelligence-based techniques are used, with varying levels of performance. This review aimed to critically appraise the literature on the assessment and comparison of various coprological techniques and/or modifications of these techniques used for equines and to identify the knowledge gaps and future research directions. We searched three databases for published scientific studies on the assessment an...
Muhonen S, Sadet-Bourgeteau S, Julliand V.Fibrous feeds are essential for horses. When developing feeding regimens promoting health and performance, we need to understand the digestion of plant cell walls and the functioning of the hindgut microbial ecosystem. Our objective was to investigate the effect of grass fibre maturity and legume forage on the hindgut microbiota and its activity. Six caecum and colon fistulated geldings were fed three diets differing in fibre composition: concentrate and late harvested grass haylage (35:65 energy ratio) (C); early and late harvested grass haylage (80:20) (G); lucerne and late harvested grass h...
Paul LJ, Ericsson AC, Andrews FM, Keowen ML, Morales Yniguez F, Garza F, Banse HE.The role of the gastric microbiome in development or persistence of equine glandular gastric disease (EGGD) remains to be investigated. Objective: The objective was to characterize the glandular mucosal and gastric fluid microbiomes of horses with and without EGGD. It was hypothesized that differences in the mucosal microbiome are associated with EGGD. Methods: Twenty-four horses were enrolled. Methods: Gastroscopy was performed and EGGD scores recorded (score 0, n = 6; score 1, n = 8; score ≥2, n = 10). Gastric fluid and pinch biopsies of healthy glandular mucosa and EGGD lesions were...
Juśkiewicz J, Fotschki B, Jaworska J, Siemieniuch M.Gastrointestinal microbiota play a key role in the nutrients digestion and hence maintaining animal health and welfare. The diet offered to the animals in captivity may differ considerably from that on natural pastures. In a stabled maintenance system, horses have a limited choice of habitat and feed. Time spend for feeding is relevant for equine welfare because the reduction of the time devoted for foraging may be responsible for inducing gastric inflammation and ulceration. Therefore, in the present study, it was hypothesized that fecal bacterial fermentative processes differ between free-ro...
Jansson A, Harris P, Davey SL, Luthersson N, Ragnarsson S, Ringmark S.Straw's low energy content means it is a roughage option for horses with low energy requirements. Previously, in a field study, straw was associated with an increased risk for gastric ulcers. This study evaluated the effect on gastric ulcers, metabolic profile and behaviour of replacing, in a forage-only ration, 50% of the daily allowance with wheat straw. Six equines were studied in a 2 × 21-day cross-over design. The control diet (CON: 100% grass forage) and the straw diet (S: 50% grass forage and 50% straw [DM basis]) were iso-energetic. Gastroscopy was performed prior to the study and on ...
Filippo PAD, Duarte BR, Albernaz AP, Quirino CR.The objective of this study was to evaluate the effect of feed restriction on some physical and blood parameters in horses kept outdoors under natural conditions. Twenty horses were deprived of food for 48 h. They were closely monitored and examined, and blood samples were taken at the beginning (0) of the experiment and 6, 12, 18, 24, 30, 36, 42 and 48 hours afterward. During the experimental period, the control group (12 animals) had free access to water and hay, while the restricted group had free access to water only. Data were submitted to two-way analysis of variance with repeated measur...
Jiménez BLM, Elghandour MMMY, Adegbeye MJ, Tirado González DN, Tirado Estrada G, Salem AZM, Pacheco EBF, Pliego AB.In the race against deadly diseases, multiple drugs have been developed as a treatment strategy in livestock. Each treatment is based on a specific mechanism to find a suitable drug. Antibiotics have become a fundamental part of the equine industry to treat bacterial diseases. These antibiotics have specific doses and side effects, and understanding each parameter allows veterinarians to avoid or limit the adverse effects of such drugs. Use of antibiotics causes microbial imbalance, decreased microbial diversity and richness in both cecal and fecal samples. Antibiotics reduced metabolites prod...
Bookbinder L, Schott HC.To describe refeeding syndrome in an equid without a history of recognized risk factors. Methods: Refeeding syndrome with marked hypophosphatemia developed in an aged miniature donkey gelding during treatment of suspected enterocolitis. Hypophosphatemia (manifested clinically as ileus and neuromuscular weakness) developed despite a short (3 day) history of hyporexia, increased body condition (7/9), and adherence to nutritional recommendations for critically ill equids. Nutritional support included nasogastric enteral feeding with a commercial equine nutrition product claiming to provide 100% o...
Rhodes DM, Madrigal R.Colic is one of the most frequent emergencies necessitating veterinary attention. Referral is not an option in many cases; therefore, the ability to diagnose and treat colic in an ambulatory setting is paramount. Portable imaging and point-of-care testing has improved the ability to identify lesions and assess the patient's status. In cases when field management is the only option, practitioners should be aware of the various treatment options available.
Roessner HA, Hurcombe SD, Klein CE, Hopster K, Engiles JB.To compare end-to-end jejunal anastomoses with a one-layer (Utrecht) and two-layer (simple continuous/Cushing) patterns. Methods: Experimental study. Methods: Eight healthy adult horses. Methods: Jejunal end-to-end anastomoses were performed in randomly assigned one-layer or two-layer patterns. Horses were recovered from surgery and monitored for complications. At 14 days, the opposite pattern was performed (cross-over design) prior to euthanasia. Duration of closures was compared between patterns. Serosal width was measured before harvesting anastomotic sites from the first procedure. Lumin...
Neudeck S, Twele L, Kopp V, Kästner S.The aim was to determine the effects of vatinoxan on dexmedetomidine plasma concentrations and effects on cardiovascular and intestinal tissue pharmacodynamics. In a prospective randomized study, six horses were premedicated intravenously with dexmedetomidine 3.5 µg kg followed by a constant-rate infusion of 7 µg kg h (group DEX) and six horses with dexmedetomidine of the same dose (bolus and constant-rate infusion) combined with vatinoxan 130 µg kg followed by 40 µg kg h (group VAT). Anaesthesia was induced with ketamine and diazepam and maintained with isoflurane. Venous bloo...
Walshe N, Cabrera-Rubio R, Collins R, Puggioni A, Gath V, Crispie F, Cotter PD, Brennan L, Mulcahy G, Duggan V.Obesity is endemic in human populations in the western society, and with mounting evidence that the intestinal ecological environment plays a major role in its pathogenesis, identification of therapies based on intestinal microbiota modulation are gaining attention. Obesity in companion animals is also a common clinical problem. We set out using a multidimensional approach, to determine the effectiveness and safety of a weight loss program for horses incorporating diet restriction and exercise. In addition, we aimed to investigate the effect of this program on the overall intestinal health of ...
Sasaki N, Nishi Y, Fujiwara Y, Takeyama T, Kumagai H, Senarathna S, Ushiya S, Tokuyama T, Tokuyama T, Tokuyama T, Mii T, Ayaki S, Matsuno K....Gastric ulcers cause appetite loss, poor body condition, and colic in horses. This study investigated the protective effect of a rice fermented extract on the gastric mucosa in 17 healthy Thoroughbreds. For one month, horses in the rice fermented extract (nine horses) and control (eight horses) groups were orally administered a rice fermented extract (100%; 0.2 ml/kg, SID) and tap water (0.2 ml/kg), respectively. Gastric endoscopic images were obtained before and one month after rice fermented extract administration. The gastric ulcer score was lower after administration (median, 1; maximum, 2...
Galiazzo G, Tagliavia C, Giancola F, Rinnovati R, Sadeghinezhad J, Bombardi C, Grandis A, Pietra M, Chiocchetti R.Colic is a common digestive disorder in horses and one of the most urgent problems in equine medicine. A growing body of literature has indicated that the activation of cannabinoid receptors could exert beneficial effects on gastrointestinal inflammation and visceral hypersensitivity. The localisation of cannabinoid and cannabinoid-related receptors in the intestine of the horse has not yet been investigated. The purpose of this study was to immunohistochemically localise the cellular distribution of canonical and putative cannabinoid receptors in the ileum of healthy horses. Distal ileum spec...
Berreta A, Kopper JJ, Alexander TL, Kogan CJ, Burbick CR.Probiotics, by definition, are live micro-organisms and should remain viable when they reach the intended site of action which is typically the cecum and/or colon. In humans, probiotics often need enteric protection to survive transit through the proximal gastrointestinal (GI) tract. Typically, equine probiotics do not advertise enteric protection and to the author's knowledge the viability of equine probiotics after exposure to the proximal GI tract has not been evaluated. The objective of this study was to evaluate the effect of an in vitro simulation of the equine proximal GI tract on probi...
Verhaar N, Breves G, Hewicker-Trautwein M, Pfarrer C, Rohn K, Burmester M, Schnepel N, Neudeck S, Twele L, Kästner S.Ischaemic postconditioning (IPoC) has been shown to ameliorate ischaemia reperfusion injury in different species and tissues. Objective: To assess the feasibility of IPoC in equine small intestinal ischaemia and to assess its effect on histomorphology, electrophysiology and paracellular permeability. Methods: Randomised in vivo experiment. Methods: Experimental jejunal ischaemia was induced for 90 min in horses under general anaesthesia. In the control group (C; n = 7), the jejunum was reperfused without further intervention. In the postconditioning group (IPoC; n = 7), reocclusion was im...
Mathewos M, Girma D, Fesseha H, Yirgalem M, Eshetu E.Gastrointestinal helminth parasite infection is a major influencing factor against the profitability of working equines all over the world. Methods: A cross-sectional study was conducted to determine the prevalence of gastrointestinal tract (GI) helminths and assess the associated risk factors in donkeys and horses in the Hawassa district. A total of 214 fecal samples were collected from randomly selected equines (112 donkeys and 102 horses) and examined for the presence of eggs of GI helminths using standard coprological techniques. Results: According to the current study, the prevalence of G...
Jota Baptista C, Sós E, Madeira de Carvalho L.Przewalski's horse (Equus ferus przewalskii) is a subspecies of Equus ferus classified as endangered by the International Union for Conservation of Nature (IUCN), whose gastrointestinal (GI) parasitism has been studied in different populations, in situ and ex situ, during the last decades. We aimed to summarize the information available on the subject. Methods: In this review, we collected information from distinct published literature, interpreted it, compared it and related the Przewalski's horse biology and ecology with different findings. Results: Many similarities can be found between the...
Giusto G, Cerullo A, Gandini M.To resolve large colon impactions, frequent enteral administration of large volumes of water (8-10 liters in a 500 kg horse) has been suggested. Furthermore, in large colon volvulus, the simultaneous presence of gastric impaction has been described as a possible predisposing factor. To describe the clinical and surgical features of horses with large colon volvulus associated with aggressive enteral fluid therapy performed to resolve an initial large colon impaction. Records of horses that underwent exploratory laparotomy at the Veterinary Teaching Hospital of Turin between 2012-2019 were revie...
Averay K, van Galen G, Ward M, Verwilghen D.Equine small intestinal resection and anastomosis is a procedure where optimizing speed, without compromising integrity, is advantageous. There are a range of different needle holders available, but little is published on the impact surgical instrumentation has on surgical technique in veterinary medicine. The objectives of this study were to investigate if the needle holder type influences the anastomosis construction time, the anastomosis bursting pressure and whether the bursting pressure is influenced by the anastomosis construction time. Single layer end-to-end jejunojejunal anastomoses w...
Hesta M, Costa M.Many horses are fed differently than their wild ancestors. They often have limited access to pasture and are fed conserved forage and concentrates rich in starch and sugars, in only 2 meals per day. Feeding practices in contrast to natural feeding behavior can lead to gastrointestinal issues. Standard nutritional evaluation is warranted because of its important role in prevention and in treatment and management of diseases. When medical and nutritional treatments are combined, success rates are higher. New techniques to characterize equine microbiota have been used, allowing for microbiota man...
Harris P, Shepherd M.Nutrition and management have enabling and supporting roles to play in the health, welfare, and performance of equines. Poor or inappropriate nutrition may therefore impose limits on an animal's ability to perform and adversely affect health and welfare. Understanding the gastrointestinal tract from a nutrition perspective can help to reduce the risk of certain clinical problems. This article outlines key factors with respect to the equine digestive tract and discusses relevant aspects of ration formation. Forage is highlighted, because inappropriate forage provision is one of the key limitati...
Murray MJ, Nout YS, Ward DL.Medical records and endoscopy images were examined for 209 horses that had gastroscopic examinations performed with a 2.5- or 3-m-long endoscope by one of the authors (MJM) during a 4-year period (1996-2000). The antrum and pylorus were viewed in 162 horses, and the duodenum was viewed in 94 horses. Of these 162 horses, the gastric squamous mucosa was seen in 157 horses and 50% or more of the glandular mucosa of the body of the stomach was seen in 156 horses. Erosions or ulcers were seen in the gastric squamous mucosa in 91 (58%) horses. Erosions or ulcers were seen in the glandular mucosa of ...
Boxell AC, Gibson KT, Hobbs RP, Thompson RC.To assess the occurrence of gastrointestinal parasites in horses in Perth. To apply polymerase chain reaction (PCR) for the identification of some species of encysted larval cyathostomes. Methods: Between February and September of 2000, the gastrointestinal tracts of 29 horses submitted to a local knackery and Murdoch University Veterinary hospital in Perth were examined post mortem for the presence of gastrointestinal parasites. Methods: The gastrointestinal tract was divided into six sections, which were screened for the presence of parasites such as Gasterophilus sp, Anoplocephala sp and Pa...
Leclere M, Costa MC.Gastrointestinal microbiota can be influenced by several factors, including diet and systemic inflammation, and in turn could act as a modulator of the allergic response. Fecal microbiota of horses with asthma has not been described. Objective: Analyze the bacterial fecal microbiota of horses with and without asthma under different environment and diet conditions, during both remission and exacerbation. Methods: Prospective observational study. Feces from 6 asthmatic and 6 healthy horses were collected under 3 different conditions: on pasture, housed indoors receiving good quality hay ("good h...
Morton AJ, Blikslager AT.Although short-term survival rates following small intestinal resection reportedly range from 48-88%, there is little information on predicting which horse may or may not survive small intestinal (SI) resection and anastomosis. The aim of this study was to identify factors that contribute to nonsurvival in horses following small intestinal resection. Medical records of horses which recovered from anaesthesia following SI resection were reviewed. Clinical and surgical variables were evaluated for their association with short-term survival using logistic regression and were reported as odds rati...
Swyers KL, Burk AO, Hartsock TG, Ungerfeld EM, Shelton JL.A study was conducted to determine whether direct-fed microbials (DFM) could be used to increase digestibility and minimize the risk of acidosis associated with feeding an increase in the amount of starch fed to horses. Fifteen mature Thoroughbred geldings were randomly assigned to 1 of 3 treatments in a 3 x 3 Latin square design balanced for carryover effects. Within each 26-d period, horses were offered grass hay + low-starch concentrate (LS; 1.2 g of starch x kg of BW(-1) x meal(-1)) from d 1 to 13 and then were abruptly changed to hay + high-starch concentrate (HS; 2.4 g of starch.kg of BW...
The Journal of parasitologyJanuary 23, 2003
Volume 88, Issue 6 1130-1134 doi: 10.1645/0022-3395(2002)088[1130:GHOPIL]2.0.CO;2
Chapman MR, French DD, Klei TR.A survey in Louisiana of gastrointestinal helminths recovered at necropsy from 117 ponies with minimal exposure to anthelmintics between 1989 and 2000 is compared with a survey conducted 20 yr earlier in the same region. An objective of this study was to determine whether species diversity has been affected by the advent and use of the macrocyclic lactone (ML) parasiticides and by the increased anthelmintic pressure on the helminth species infecting the general equine population. Twenty-six cyathostome species and 8 strongyle species were recovered. Two cyathostome species that were not found ...
Merritt AM, Burrow JA, Hartless CS.To evaluate the effect on equine duodenal motility of some analgesic agents commonly used to treat colic. Methods: 4 healthy adult healthy horses--2 mares and 2 geldings--which were carrying an indwelling gastric cannula made of silastic rubber. One horse also carried 2 long-term indwelling bipolar electrodes that had been sutured onto the duodenum and jejunum. Methods: To ensure an empty stomach, solid food was withheld from horses for around 20 hours prior to an experiment. Using videoendoscopic guidance, an 8-F catheter with 3 small, discrete pressure sensors was passed through the gastric ...
Traversa D, Iorio R, Capelli G, Paoletti B, Bartolini R, Otranto D, Giangaspero A.Gastric habronemosis of horses caused by Habronema microstoma and Habronema muscae (Nematoda, Spirurida) is characterized by catarrhal gastritis, diarrhoea, progressive weight loss and ulcers. Despite its importance in the equine industry and in clinical practice, knowledge of the epidemiology of this infection is still incomplete as diagnosis in live animals is challenging. A two-step semi-nested PCR assay using ribosomal DNA (rDNA) markers has recently been used for the molecular diagnosis in vivo of gastric habronemosis based on the detection of H. microstoma and/or H. muscae DNA in equine ...
Busechian S, Sgorbini M, Orvieto S, Pisello L, Zappulla F, Briganti A, Nocera I, Conte G, Rueca F.Equine gastric ulcer syndrome (EGUS) affects various categories of horses worldwide. This syndrome is now divided into two different diseases, based on the presence of lesions on either the squamous (Equine Squamous Gastric Disease, ESGD) or the glandular (Equine Glandular Gastric Disease, EGGD) mucosa. Diagnosis is based on the evaluation of the presence of gastric lesions with gastroscopic examination. As a gastroscopy can be considered expensive by clients, therapy is started often on the basis of clinical signs only. The aim of this study was to validate a questionnaire to detect the risk ...
Sellon DC, Monroe VL, Roberts MC, Papich MG.To determine an infusion rate of butorphanol tartrate in horses that would maintain therapeutic plasma drug concentrations while minimizing development of adverse behavioral and gastrointestinal tract effects. Methods: 10 healthy adult horses. Methods: Plasma butorphanol concentrations were determined by use of high-performance liquid chromatography following administration of butorphanol by single IV injection (0.1 to 0.13 mg/kg of body weight) or continuous IV infusion (loading dose, 17.8 microg/kg; infusion dosage, 23.7 microg/kg/h for 24 hours). Pharmacokinetic variables were calculated, a...
Tyma JF, Epstein KL, Whitfield-Cargile CM, Cohen ND, Giguère S.OBJECTIVE To determine the effects of oral omeprazole administration on the fecal and gastric microbiota of healthy adult horses. ANIMALS 12 healthy adult research horses. PROCEDURES Horses were randomly assigned to receive omeprazole paste (4 mg/kg, PO, q 24 h) or a sham (control) treatment (tap water [20 mL, PO, q 24 h]) for 28 days. Fecal and gastric fluid samples were collected prior to the first treatment (day 0), and on days 7, 28, 35, and 56. Sample DNA was extracted, and bacterial 16S rRNA gene sequences were amplified and sequenced to characterize α and β diversity and differential ...
Okamura K, Sasaki N, Yamada M, Yamada H, Inokuma H.Although extensive work has been done to elucidate the beneficial and unfavorable effects of gastrointestinal prokinetic agents in humans, little is known on the effects of these agents in horses. In this study, we compared the effects of mosapride, metoclopramide, cisapride, and lidocaine on equine gastric emptying, jejunal and caecal motility and evaluated these agents' adverse drug reactions (ADRs). Methods: Seven healthy adult Thoroughbreds. Methods: Mosapride 1.0mg/kg and 2.0mg/kg, metoclopramide 0.2mg/kg, and cisapride 1.0mg/kg were dissolved in 100mL distilled water for oral administrat...
Hamamoto-Hardman BD, Steffey EP, Weiner D, McKemie DS, Kass P, Knych HK.The objective of the current study was to describe and characterize the pharmacokinetics and selected pharmacodynamic effects of morphine and its two major metabolites in horses following several doses of morphine. A total of ten horses were administered a single intravenous dose of morphine: 0.05, 0.1, 0.2, or 0.5 mg/kg, or saline control. Blood samples were collected up to 72 hr, analyzed for morphine, and metabolites by LC/MS/MS, and pharmacokinetic parameters were determined. Step count, heart rate and rhythm, gastrointestinal borborygmi, fecal output, packed cell volume, and total prote...
McConnico RS, Morgan TW, Williams CC, Hubert JD, Moore RM.To determine pathophysiologic effects of phenylbutazone on the equine right dorsal colon (RDC). Methods: 12 healthy adult horses. Methods: A controlled crossover observational study was conducted. Clinical and serum variables, colonic inflammation (histologic grading), and measurement of myeloperoxidase (MPO) activity, malondialdehyde (MDA) and prostaglandin E(2) (PGE(2)) concentrations, ingesta volatile fatty acid (VFA) content, and arterial blood flow in the RDC were evaluated for a 21-day period in horses administered phenylbutazone (8.8 mg/kg, PO, q 24 h) or a control substance. Results: D...
Little D, Tomlinson JE, Blikslager AT.Post operative ileus (POI) remains an important cause of post operative morbidity and mortality in the horse. However, clinical progression of naturally occurring cases of POI in both horse and man does not entirely support the 'neurogenic' hypothesis as the sole mechanism of POI; and the hypothesis that inflammation plays a major role at 12-24 h after surgery requires validation. Objective: An inflammatory infiltrate in the muscularis externa and myenteric plexus of equine jejunum is present 18 h following a period of ischaemia. Methods: Samples of normal jejunum, jejunum from the proximal re...
Noble G, Edwards S, Lievaart J, Pippia J, Boston R, Raidal SL.Safety of meloxicam, a potent NSAID with selective COX-2 inhibition, has not been evaluated in horses. Objective: To evaluate pharmacokinetics and safety of single and repeated oral doses of meloxicam in adult horses. Methods: Forty-nine healthy, university-owned adult lightbreed horses. Methods: Study conducted in 2 parts. Part I addressed pharmacokinetics of single oral dose meloxicam (0.6 mg/kg) in 16 horses. Part II, 33 horses were randomly assigned to 5 treatment groups to assess prolonged administration (0.6 mg/kg PO q24h for 6 weeks, n = 7) or higher doses (1.8 mg/kg, n = 7, or 3.0 mg/k...
Wise JC, Wilkes EJA, Raidal SL, Xie G, Crosby DE, Hale JN, Hughes KJ.Grading of equine gastric ulcer syndrome (EGUS) is undertaken in clinical and research settings, but the reliability of EGUS grading systems is poorly understood. Objective: Investigate interobserver and intraobserver reliability of an established ordinal grading system and a novel visual analog scale (VAS), and assess the influence of observer experience. Methods: Sixty deidentified gastroscopy videos. Methods: Six observers (3 specialists and 3 residents) graded videos using the EGUS Council (EGUC) system and VAS. Observers graded the videos three 3 for each system, using a cross-over design...
Murray MJ, Schusser GF.A glass combined pH-reference electrode was placed in the stomachs of 5 adult horses and pH was recorded every 6 mins for 24 h while (1) feed and all bedding materials were withheld for 24 h (unfed), (2) horses had free access to Timothy grass hay for 24 h (fed), and (3) horses had free access to Timothy grass hay and were treated with ranitidine, 6.6 mg/kg body weight, orally, every 8 h for 48 h (fed + ranitidine). There was a significant (P = 0.007) difference in median 24-h gastric pH amongst the 3 protocols, the value being 3.1 in fed horses and 1.55 in unfed horses (P = 0.05) and 4.6 in f...
Andrews FM, Reinemeyer CR, McCracken MD, Blackford JT, Nadeau JA, Saabye L, Sötell M, Saxton A.Equine gastric ulcer syndrome (EGUS) represents a major health problem in performance horses. Much debate exists regarding endoscopic gastric ulcer scoring systems and their ability accurately to predict severity or depth of gastric ulcers. The purpose of this study was to evaluate the ability of an endoscopist to count gastric ulcers and predict gastric ulcer severity or depth using 2 endoscopic scoring systems and compare them to the same gastric ulcers see on necropsy and histopathology. Endoscopic examination of the stomach was performed under general anaesthesia on 23 mixed breed yearling...
Whitfield-Cargile CM, Chamoun-Emanuelli AM, Cohen ND, Richardson LM, Ajami NJ, Dockery HJ.Non-steroidal anti-inflammatory drugs (NSAIDs) are routinely used in both veterinary and human medicine. Gastrointestinal injury is a frequent adverse event associated with NSAID use and evidence suggests that NSAIDs induce gastrointestinal microbial imbalance (i.e., dysbiosis) in both animals and people. It is unknown, however, whether cyclooxygenase (COX)-2-selective NSAIDs induce dysbiosis, or if this phenomenon occurs in horses administered any class of NSAIDs. Therefore, our objectives were to determine whether the composition and diversity of the fecal microbiota of adult horses were alt...
Furr M, Taylor L, Kronfeld D.Gastroendoscopic surveys have shown that horses in race training have a greater prevalence of gastric ulceration than sedentary horses. To determine if exercise affects gastric endocrine function the following experiment was performed. Four horses were fed total mixed ration of ground corn and chopped hay at 2% of their body weight, divided into 2 equal portions, daily. Horses were fasted overnight, and serum gastrin concentration was determined just before and 2 hours after feeding. The horses were then sprint trained on a high speed treadmill for 6 weeks. The response of serum gastrin to fee...
Husted L, Sanchez LC, Olsen SN, Baptiste KE, Merritt AM.Stall housing has been suggested as a risk factor for ulcer development in the equine stomach; however, the exact pathogenesis for this has not been established. Objective: To investigate the effect of 3 environmental situations (grass paddock, stall alone or stall with adjacent companion) on pH in the proximal and the ventral stomach. Methods: Six horses with permanently implanted gastric cannulae were used in a randomised, cross-over, block design. Each horse rotated through each of three 24 h environmental situations. Horses remained on their normal diet (grass hay ad libitum and grain b.i....
Dabareiner RM, White NA.Medical records from all horses with large colon impaction admitted between 1985 and 1991 were examined. Large colon impaction was diagnosed in 147 of 1,100 (13.4%) horses with colic. One hundred thirty horses were admitted for further evaluation of acute onset of abdominal pain after having been examined and treated by referring veterinarians, and 17 horses that were hospitalized for unrelated medical problems developed large colon impaction. Female horses (92/147; 62.6%) were more commonly affected than males. The age ranged from 1 to 29 years (median, 7.1 years). Mean duration of clinical s...
Bennett RC, Steffey EP.REGIONAL ADMINISTRATION: There is limited, but convincing, evidence that epidural administration of morphine and some other mu-agonist opioids consistently relieves regional pain in horses. In addition, this effect is not accompanied by notable undesirable effects. On the other hand, a clinically important analgesic action has not been demonstrated for similarly administered kappa-agonist opioids. There has been little objective data presented to support the analgesic effectiveness of intra-articularly administered opioids in horses. However, the evidence of local opioid receptors legitimately...
Malone E, Ensink J, Turner T, Wilson J, Andrews F, Keegan K, Lumsden J.To determine if intravenous lidocaine is useful and safe as a treatment for equine ileus. Methods: Prospective double-blinded placebo-controlled trial. Methods: Horses (n = 32) with a diagnosis of postoperative ileus (POI) or enteritis and that had refluxed >20 L or had been refluxing for >24 hours. Methods: Refluxing horses were administered lidocaine (1.3 mg/kg intravenously [IV] as a bolus followed by a 0.05 mg/kg/min infusion) or saline (0.9% NaCl) solution placebo for 24 hours. Variables evaluated included volume and duration of reflux, time to 1st fecal passage, signs of pain, anal...
Coverdale JA.Intensive management practices in the horse industry present a unique challenge to the microbiome of the large intestine. Common management practices such as high-concentrate diets, low forage quality, meal feeding, and confinement housing have an impact on intestinal function, specifically large intestinal fermentation. The microbiome of the equine large intestine is a complex and diverse ecosystem, and disruption of microbiota and their environment can lead to increased incidence of gastrointestinal disorder. Digestion in the horse can be improved through a variety of approaches such as feed...
Galiazzo G, Tagliavia C, Giancola F, Rinnovati R, Sadeghinezhad J, Bombardi C, Grandis A, Pietra M, Chiocchetti R.Colic is a common digestive disorder in horses and one of the most urgent problems in equine medicine. A growing body of literature has indicated that the activation of cannabinoid receptors could exert beneficial effects on gastrointestinal inflammation and visceral hypersensitivity. The localisation of cannabinoid and cannabinoid-related receptors in the intestine of the horse has not yet been investigated. The purpose of this study was to immunohistochemically localise the cellular distribution of canonical and putative cannabinoid receptors in the ileum of healthy horses. Distal ileum spec...
van Loon JP, Jonckheer-Sheehy VS, Back W, van Weeren PR, Hellebrekers LJ.Recognition and management of equine pain have been studied extensively in recent decades and this has led to significant advances. However, there is still room for improvement in the ability to identify and treat pain in horses that have undergone emergency gastrointestinal surgery. This study assessed the validity and clinical application of the composite pain scale (CPS) in horses after emergency gastrointestinal surgery. Composite pain scores were determined every 4h over 3 days following emergency gastrointestinal surgery in 48 horses. Inter-observer reliability was determined and another...
Murray MJ, Haven ML, Eichorn ES, Zhang D, Eagleson J, Hickey GJ.Seventeen Thoroughbred horses with moderate to severe gastric ulceration were purchased from a race track within 10 days of racing and were treated once daily with either omeprazole (9 horses) or vehicle (8 horses) and evaluated gastroscopically for ulcer healing. Horses were administered omeprazole (1.5 mg/kg bwt/day) or vehicle by nasogastric tube once daily. Gastroscopic examination was performed on Days 0, 4, 7, 11, 14, 17, 21, 24 and 28, until lesions healed completely. Selected images of gastric lesions were captured by computer at each endoscopic examination, with a measuring caliper in...
