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.
Milne EM, Pogson DM, Doxey DL.Poisoning with Senecio jacobaea (ragwort) is a common cause of chronic liver disease in horses in Britain. The major clinical signs are the result of hepatic failure but gastric impaction has recently been associated with the disease. The present paper describes three cases of secondary gastric impaction associated with ragwort poisoning. In each case the impaction was the cause of death or necessitated euthanasia.
Murray MJ, Grodinsky C, Cowles RR, Hawkins WL, Forfa RJ, Luba NK.Gastroendoscopic examinations were conducted on thirty-two 2- to 60-day-old Thoroughbred foals on 5 breeding farms. Repeat gastroendoscopic examinations were performed 35 to 135 days after the initial examination, with the age of foals ranging from 39 to 190 days. On initial endoscopic examination, lesions consisting of ulcers and/or erosions were most prevalent in the stratified squamous epithelial mucosa adjacent to the margo plicatus along the greater curvature of the stomach (15 of 32 foals), and were observed much less frequently at other sites within the stomach. In addition to ulcers an...
Ehrhardt EE, Lowe JE.The reliability of abdominal auscultation was investigated via an observer variation study. Clinicians listened to a variety of minute-long equine gut sound recordings. They evaluated the amount of gut sounds as 'absent', 'decreased', 'normal', or 'increased'. They subsequently evaluated the same recordings replayed in a different order. Intra- and inter-observer agreement was measured by the statistic kappa. There was significant intra-observer (kappa 0.57) agreement, but less agreement between observers (kappa 0.37). The best agreement was on the classification of sound tracks as 'absent' (i...
Ross MW, Cullen KK, Rutkowski JA.Myoelectric activity of the ileum, cecum, and right ventral colon (RVC) was studied in 4 mature ponies. Eight Ag-AgCl bipolar recording electrodes were sutured to the seromuscular layer of the ileum (2 electrodes), cecum (4 electrodes), and RVC (2 electrodes). Myoelectric activity was studied beginning 10 days after surgery. Eight, 60-minute recording sessions were performed in each pony during the interdigestive period, which was the period 3 to 7 hours after the morning feeding. On separate days, food was withheld for 24 hours, and 90-minute recordings were obtained during the nonfeeding per...
Simmons HA, Ford EJ.The rate of flow of fluid from the caecum and from the large colon was measured in four Shetland-type ponies fed a hay diet. In two ponies with cannulas in the caecum and at the origin of the right ventral colon, a continuous intracaecal infusion of a solution of chromium EDTA was used and samples were obtained from the cannula at the origin of the right ventral colon. Based on four determinations, the liquid flow from the caecum was 54.2 +/- 1.89 litres d-1. In the other two ponies with cannulas in the origin of the right ventral colon and near the end of the right dorsal colon, a continuous ...
Kotzé SH, Soley JT.The ileocaecal junction mucosal surface morphology of 5 horses and 1 donkey was examined using scanning electron microscopy and light microscopy. Based on differences in surface morphology, the junction could be divided into 4 distinct regions. The distal extremity of the ileum was characterized by the presence of typical finger-like villi followed by a narrow zone displaying short, stubby villi which gradually merged into a 3rd region representing the true transitional zone between the small and large intestine. In this region the villi fused, forming low ridges arranged in circular, semi-cir...
Mair TS, Taylor FG, Harbour DA, Pearson GR.Combined immunodeficiency syndrome is an inherited disorder of the Arabian breed of horses. Affected foals usually die of infectious disease within the first few months of life, and the respiratory tract is the commonest site of infection. This report describes the clinical and pathological features of a case which showed signs of alimentary and respiratory infections. Intestinal infection by coronavirus (not previously recorded in cases of the syndrome) and cryptosporidia was identified. Histopathological evidence also suggested the presence of an adenovirus infection.
Kiper ML, Traub-Dargatz J, Curtis CR.A computer-based search was conducted of medical and necropsy records of horses admitted to the teaching hospital from Jan 1, 1979, to Dec 31, 1987, to obtain the records of all horses admitted to the hospital for colic and subsequently found to have gastric rupture. Fifty cases of gastric rupture were found. The records were reviewed to obtain data regarding peritoneal fluid analysis. Cell counts of these samples were often erroneous because debris and clumps of bacteria were counted when most WBC were lysed. A cross-sectional study of gastric rupture cases versus all other colic cases regard...
Mair TS, Taylor FG, Brown PJ.Two horses affected by chronic, intermittent colic were found, at post-mortem examination, to have localized annular thickening of a segment of the duodenum. Histological examination of the lesion in both cases revealed a tumour composed of bundles of oval or spindle-shaped cells that stained as muscle with van Gieson stain. The histological diagnosis was leiomyosarcoma. The tumour had caused partial bowel obstruction in both horses.
Smyth GB, Duran S, Ravis W, Clark CR.Histamine type II (H2) antagonists inhibit gastric acid secretion and are useful in treating gastric and duodenal ulcer disease. To provide some information on the pharmacokinetics of the H2 antagonist cimetidine, adult horses were given 3.3 mg/kg cimetidine intravenously (iv) or 3.3 and 10 mg/kg orally. Plasma cimetidine concentrations after 3.3 mg/kg orally were too low to measure. Following 3.3 mg/kg iv, cimetidine displayed two-compartment characteristics with a t1/2 of 0.083 +/- 0.039 h and t1/2 of 2.23 +/- 0.64 h. The total body clearance was 0.443 +/- 0.160 litre/h/kg and the mean resid...
Young DW, Smyth GB.The predominant form of gastrin in the antral mucosa of the stomach of virtually all species previously examined is the 17 amino acid peptide little gastrin (G17). This report describes the occurrence in equine antral mucosa of an immunoreactive form of gastrin with elution properties on Sephadex G-50 superfine similar to human unsulfated big gastrin (G34-I). This putative equine big gastrin was a major component of the gastrin immunoreactivity present. A second peak of activity in equine antral mucosa eluted in an identical manner to human little gastrin (hG17-I). Inhibition curves of equine ...
Murray MJ, Murray CM, Sweeney HJ, Weld J, Digby NJ, Stoneham SJ.Gastroendoscopic examinations were conducted on 75 Thoroughbred foals aged two to 85 days on seven breeding farms in England and Ireland. The foals showed no signs of gastric disease. There was no significant difference between lesion prevalence in foals in England (16 of 28 foals; 57 per cent) or Ireland (22 of 47 foals; 47 per cent). Neither was there any sex predilection (18 of 36 males; 20 of 39 females). Lesions were most prevalent in foals under 10 days old (8 of 9) and least prevalent in foals older than 70 days (3 of 10). Lesions occurred most frequently in the squamous mucosa immediat...
Coenen M.Ponies were fed hay (n = 21) or mixed feed (n = 27; 128 g crude protein, 175 g crude fibre/kg dry matter) for at least 14 days (treatment against parasites with ivermectin before the experimental period). The feeding level was 18 g dry mater/kg body weight/day. After the feeding period (the experiments were conducted to investigate the water and electrolyte content of the alimentary tract in dependence on feed, feeding time and physical exercise) the ponies were slaughtered and the stomachs were visually controlled for the occurrence of ulcers. In the hay group no gastric ulcers were observed,...
Ford TS, Freeman DE, Ross MW, Richardson DW, Martin BB, Madison JB.The case records of 26 horses with ileocecal intussusception over a 7-year period were reviewed to determine clinical features of the disease and response to treatment. The median age of horses with ileocecal intussusception was 1 year and ranged from 2 weeks to 19 years. There was no apparent gender or breed predisposition to this disease. An acute form of ileocecal intussusception was diagnosed in 19 horses with signs of moderate to severe abdominal pain of less than or equal to 24 hours' duration, and a chronic form was diagnosed in 7 horses with signs of intermittent, mild to moderate abdo...
Snyder JR, Tyler WS, Pascoe JR, Olander HJ, Bleifer DR, Hinds DM, Neves JW.Microvascular circulation of the ascending colon in healthy horses was studied using microangiography, light microscopy, and scanning electron microscopy. The pelvic flexure with 30 cm of ventral and dorsal colon attached was removed from 14 adult horses immediately after horses were euthanatized. The lumen was flushed with warm water, and this section of the ascending colon was placed in a 37-C bath of isotonic NaCl. In sections from 8 horses, colic vessels were perfused with a radio-opaque medium for microangiography. After angiographic evaluation, tissue sections were prepared for light mic...
Kalsbeek HC.Non-surgical correction of nephrosplenic entrapment of the left colon was attempted in 27 cases. In two cases the method failed and a laparotomy was necessary. Two other horses had a recurrence, one of which underwent laparotomy because of torsion of the caecal body.
Sangiah S, MacAllister CC, Amouzadeh HR.The basal gastric pH and free acid contents from five young adult healthy horses were determined at one hour intervals for eight hours. The basal gastric pH and free acid contents varied from 1.63 +/- 0.06 to 1.97 +/- 0.11 and 26.42 +/- 4.14 to 17.92 +/- 5.28 mmol litre-1, respectively. Misoprostol, a methylester analogue of prostaglandin (5 micrograms kg-1, orally) produced a time-dependent increase in the basal gastric pH to above 3.5 (P less than 0.05) at three, four and five hours after administration with a concomitant reduction of 80 to 90 per cent in the basal gastric free acid contents...
Krecek RC, Reinecke RK, Horak IG.Between 1980 and 1982, the gastrointestinal tracts of 17 horses which had been grazing on mixed grassveld at Potchefstroom and bushveld at Onderstepoort in the province of Transvaal, Republic of South Africa, were examined at necropsy and processed for parasite recovery. The large strongyles and their prevalences were as follows: Strongylus vulgaris and associated lesions (88-94%), Strongylus edentatus (24%), Strongylus equinus (30%), Triodontophorus nipponicus (35%) and Craterostomum acuticaudatum (18%). The seven most prevalent and abundant cyathostomes collected were Cylicostephanus longibu...
Murray MJ.Of 183 foals examined by use of gastroendoscopy during 1987 and 1988, 94 had gastric lesions. Sixty-eight of 120 foals in the 1- to 85-day-old age range had endoscopically confirmed gastric lesions, and 26 of 63 foals in the 90- to 310-day-old age range had gastric lesions. Lesions were observed most frequently in the stratified squamous mucosal epithelium, particularly adjacent to the margo plicatus. Lesions were observed in the gastric glandular mucosa in 26 of the 94 foals with gastric lesions, and with a greater frequency in foals with a clinical disorder than in foals with no disorder (27...
Takehana K, Abe M, Iwasa K, Hiraga T.Complex carbohydrates were examined in glandular cells of the horse duodenal gland by using lectin histochemical techniques. In the horse, the duodenal gland was distributed in the area from the uppermost part of the small intestine to a point about 6m caudal to the pylorus. It consisted of two types of cells, mucous and serous cells. The former was found in glands distributed almost all over this part, but the latter was present in glands distributed restrictedly to the uppermost part of the small intestine at a point about 10 cm caudal to the pylorus. The cytoplasm of the mucous cell contain...
Brusie RW, Sullins KE, Silverman DG, Rosenberger JL.Arteriovenous (ischaemic strangulating obstruction, ISO) and venous obstructions (haemorrhagic strangulating obstruction, HSO) were created for 70 min in the small intestine of eight anaesthetised horses, and ISO was created in four horses for 2 h and four horses for 3 h at the sternal and diaphragmatic flexures of the large colon. Five minutes following release of the occlusions, sodium fluorescein 20 per cent (0.5 mg/kg bodyweight intravenously) was administered. Serial quantitative measurements of serosal surface fluorescence of the injured segments and a control segment were made at 2, 10,...
Bertone AL, VanSoest PJ, Johnson D, Ralston SL, Stashak TS.Fecal excretion of a particulate marker, ytterbium (Yb), was evaluated in 9 horses before surgery and 3 weeks, 3 months, and 6 months (4 trials) after sham-operation (group 1; n = 3) or extensive large colon resection (group 2; n = 6). Fecal excretion curves of total Yb excretion, loge Yb excretion, % Yb excretion, loge % Yb excretion, and cumulative % Yb excretion were evaluated, and kinetic analysis was performed on the loge Yb excretion curves to detect mixing pools and to calculate the fractional rate of particulate passage, turnover rate, and pool size. Calculations were performed to dete...
Campbell-Thompson M.The goals of surgical therapy in foal gastroduodenal ulcer disease are the elimination of abdominal pain, healing of mucosal ulcerations, and prevention of complications. Gastrojejunostomy has been used with success in both pyloric and duodenal ulcerations that have progressed to gastric outflow obstruction. Gastrojejunostomy has resulted in rapid healing of gastritis and esophagitis and resolution of aspiration pneumonia and biliary stasis without recurrence of duodenal ulceration.
Davies JV.Perhaps because of the inherent difficulty in using horses as experimental animals, only a relatively small amount of data is as yet available regarding normal equine gut motility. However, it is clear that the horse is fundamentally similar to other mammalian species studied. The neural and humoral control of gut activity requires much exploration; it is likely that, in the horse, some of this information will be derived during the investigation of the effects of various substances that might have clinical relevance. This is alluded to in the chapter that follows (The Effects of Pharmacologic...
Wolfman EF.Operations for intestinal ischemia are frequently done by veterinarians. In equine surgery those conditions commonly producing ischemia are intussusception, volvulus, bowel obstructions, and incarcerated hernias. In an attempt to predict intraoperative bowel viability after the restoration of circulation, a variety of adjuvant methods have been investigated. There is little question that of the techniques currently available, sodium fluorescein injected intravenously approaches the ideal in predicting nonviability in humans and in most animal models. Furthermore, it is safe, takes little opera...
Ross MW.Cecal impaction and cecal perforation, the two most common equine cecal diseases, are thought to develop after slowing or interruption of a single progressive motility pattern, which begins in a pacemaker area near the apex, occurs once every 3 minutes, and propels ingesta from the cecum to the right ventral colon. Rectal examination in horses with cecal impaction is the most useful technique to grade the severity of the condition. Medical treatment is undertaken if the impaction is judged to be mild to moderate. Surgical correction of cecal impaction in severe cases requires a ventral midline...
Lefebvre RA, Callens C, Van Colen I, Delesalle CJG.Postoperative ileus (POI) remains an important cause of death in horses. The recently developed selective 5-HT receptor agonists such as prucalopride target 5-HT receptors on myenteric cholinergic neurons to enhance acetylcholine release and GI motility. No clearcut in vitro evaluation whether highly selective 5-HT receptor agonists enhance submaximal cholinergic neurotransmission towards the muscle layer has been performed in horses. Objective: To identify functional 5-HT receptors in equine jejunum. Methods: In vitro experimental study. Methods: Circular and longitudinal smooth muscle strips...
Nunn FG, Pirie RS, McGorum B, Wernery U, Poxton IR.There is much evidence to suggest that group III Clostridium botulinum (types C and D) are involved in the aetiology of equine grass sickness (EGS). Antibodies have been detected previously in the blood and high levels associated with resistance to disease. Specific mucosal antibodies in the gastrointestinal (GI) tract are likely to be important in protection, and this study was performed to ascertain if such antibodies could be detected and if their levels were related to disease state. Objective: To develop a method for quantifying IgA antibodies to C. botulinum types C and D in the GI tract...
Andrews FM, Doherty TJ, Blackford JT, Nadeau JA, Saxton AM.To determine the effects of orally administered omeprazole, as enteric-coated capsules, on baseline and stimulated gastric acid secretion in horses. Methods: 5 healthy 8-year-old mixed-breed horses fitted with gastric cannulas. Methods: Enteric-coated granules of omeprazole were mixed with corn syrup and administered orally once daily for 5 consecutive days. On days 1 and 5 beginning 5 hours after omeprazole administration, 4 gastric fluid samples were collected, each for 15 minutes, via the gastric cannula (baseline samples). Pentagastrin was administered IV as a constant infusion for the sub...
Ramaswamy CM, Eades SC, Venugopal CS, Hosgood GL, Garza F, Barker SA, Moore RM.To compare plasma endothelin (ET)- like immunoreactivity between healthy horses and those with naturally acquired gastrointestinal tract disorders. Methods: 29 healthy horses and 142 horses with gastrointestinal tract disorders. Methods: Blood samples were collected from healthy horses and from horses with gastrointestinal tract disorders prior to treatment. Magnitude and duration of abnormal clinical signs were recorded, and clinical variables were assessed via thorough physical examinations. Plasma concentrations of ET-like immunoreactivity were measured by use of a radioimmunoassay for huma...
Coenen M.Ponies were fed hay (n = 21) or mixed feed (n = 27; 128 g crude protein, 175 g crude fibre/kg dry matter) for at least 14 days (treatment against parasites with ivermectin before the experimental period). The feeding level was 18 g dry mater/kg body weight/day. After the feeding period (the experiments were conducted to investigate the water and electrolyte content of the alimentary tract in dependence on feed, feeding time and physical exercise) the ponies were slaughtered and the stomachs were visually controlled for the occurrence of ulcers. In the hay group no gastric ulcers were observed,...
Solinger N, Sonea IM.Tachykinins have profound effects on equine intestinal motility, but the distribution of the neurokinin receptors (NKRs) through which they act is unknown. This study reports the distribution of one of these receptors, the neurokinin-1 receptor (NK1R), in smooth muscle throughout the equine intestinal tract. Objective: To quantify the distribution of the NK1R, based upon mRNA expression, in smooth muscle of different regions of the equine intestinal tract. Methods: Nine regions of the intestinal tract were sampled in 5 mature horses. Total RNA was isolated from smooth muscle and reverse transc...
Schusser GE, White NA.To determine the number of myenteric plexuses and neurons in the large colon of clinically normal horses and whether the number was decreased in the large colon of horses with colon disease. Methods: Prospective study. Methods: Colon samples from 15 clinically normal horses and 31 horses with colon disease. Methods: Samples were obtained, fixed, and stained with H&E. The number of myenteric plexuses and neurons and longitudinal muscle thickness were determined in each segment of colon for clinically normal horses. Counts for segments were compared with each other and with counts in the sam...
Roberts MC, Seawright AA.Colic was induced in horses and ponies following topical or intravenous (iv) administration of amitraz, a formamidine acaricide. The condition was characterised by rapid cessation of intestinal sounds, stasis, extensive impaction and tympany throughout the large colon. Three animals that were necropsied had a faecalith obstructing the proximal small colon aboral to marked colonic impaction. A reproducible and reversible impaction colic syndrome could be induced by an iv injection of 1 mg amitraz/kg body weight in solvent. There were immediate central nervous system and intestinal signs. Large ...
Bass LG, Peña-Álvarez P, Hidalgo-Dittel JD, Robles-Herrera FD, Cappella-Flores PM, Zúñiga-Cortés DS, Olivares RWI.Sarcina spp. is a Gram-positive, coccoid microorganism that forms tetrads or octets, and is observed with a characteristic "bundle" arrangement. The most recognized species are Sarcina ventriculi and Sarcina maxima. It has been described as part of the normal microbiota in horses and cats, but it has also been linked to abomasal bloat in goats, lambs, and calves, although its causality has not been proven yet. This work presents the case of a 3-months-old female horse that died of generalized tympanism. Macroscopic findings showed mild cyanosis and abundant gas in the lumen of the stomach, and...
Kamali MF, Wilson AC, Acquisto NM, Spillane L, Schneider SM.Flunexin is a nonsteroidal anti-inflammatory drug approved for veterinary use in horses and cattle. Acepromazine is a phenothiazine derivative used in horses, dogs, and cats. Human exposure to these substances is rare. Methods: We report a case of a human injection of two equine medications, flunixin and acepromazine, which resulted in altered mental status, respiratory alkalosis, gastrointestinal bleeding, and elevation of liver transaminases in a 43-year-old woman who worked as a horse trainer. The patient intentionally self-injected these medications and subsequently presented to the Emerge...
Mahne AT, Janse van Rensburg D, Hewetson M.A 4-year-old Thoroughbred gelding underwent an explorative celiotomy for a suspected small intestinal obstruction. During surgery, an impacted diverticulum of the ileum was suspected, necessitating a jejunocaecostomy. The owner opted for euthanasia. On post-mortem examination and histopathology, a true diverticulum on the mesenteric side of the ileum, with ileal hypertrophy, was diagnosed.
Hillyer MH, Smith MR, Milligan PJ.Ileus (functional obstruction of aboral gastrointestinal transit) is an uncommon cause of gastrointestinal dysfunction and colic in the horse. A number of specific conditions have been previously reported in association with ileus. This report describes the recognition of primary gastric and small intestinal ileus of undetermined cause in a series of post parturient mares. Objective: To describe the clinical features, treatment and outcome of a series of episodes of primary gastric and small intestinal ileus. Methods: A retrospective study was performed of colic episodes seen in an equine prac...
Intemann S, Reckels B, Schubert DC, Wolf P, Kamphues J, Visscher C.Evidence has already been provided that feed-borne mold spores and endotoxins can trigger chronic, non-infectious respiratory disease if inhaled. Furthermore, deficiencies in feed microbiology are suspected to trigger gastrointestinal and liver disorders in horses, but the connection needs further clarification. Most of the previous studies regarding horse feed hygiene focused on forage, whereas research regarding hygienic quality of concentrates is scarce. In the present study, results of reports on hygienic quality of compound feed and cereals for horses were evaluated secondarily. Results i...
Needles RK, Dubois MS.This case report documents an unusual case of persistent colic in a horse caused by an anomalous vascularized band of tissue running between the visceral surface of the liver and the mesentery of the large colon at the level of the sternal/diaphragmatic flexures. The horse was presented with a history of exhibiting signs of mild persistent colic that were suspected to be caused by displacement of the large colon. Volvulus of the large colon was identified during exploratory celiotomy. The band of tissue was transected, and the displacement corrected. The horse made an uneventful recovery. Trai...
Freeman DE, Ferrante PL, Palmer JE.A Latin square design was used to compare the effects of laxatives and a corresponding volume of water on gastrointestinal tract function in 4 healthy horses. Horses were intragastrically infused with each of the following: dioctyl sodium sulfosuccinate (DSS; 50 mg/kg of body weight); magnesium sulfate (0.5 g/kg--low dosage); magnesium sulfate (1.0 g/kg--high dosage); and an equal volume of water (6 L) given as a control infusion. From 5 to 33 hours after the high dosage of magnesium sulfate, feces were slightly softer than usual in all horses. In 1 horse, DSS caused mild colic, hyperpnea, and...
Kelleher ME, Puchalski SM, Drake C, le Jeune SS.To evaluate the sensitivity and specificity of direct digital abdominal radiography for the diagnosis of enterolithiasis in equids and to assess the effect of the number and anatomic location of enteroliths and gas distention of the gastrointestinal tract on diagnostic sensitivity of the technique. Methods: Retrospective case series. Methods: 238 horses and ponies ≥ 1 year old that underwent digital abdominal radiography with subsequent exploratory celiotomy or postmortem examination. Methods: For each case, 3 reviewers independently evaluated radiographic views. Radiographic images were eva...
Brøkner C, Nørgaard P, Hansen HH.The ingestive and post-digestion effect of a blend of special essential oil compounds (EO) on eating, chewing and faecal parameters were measured in horses. Ingestive effects appear after no adaptation. Post-digestion effects appear after adaptation. Six Icelandic horses were assigned to two groups in a Latin Square subplot design with EO treatments to four different roughage types and four different concentrates. The horses were fed four different roughage meals and two different concentrate meals on each of the four sampling days. Eating time and saliva were observed during meals. Jaw moveme...
McConnico RS, Stokes AM, Eades SC, Moore RM.To examine the secretory response (in the presence and absence of prostaglandin inhibition) in vitro and structural alterations of colonic mucosa in horses after intragastric administration of black walnut extract (BWE). Methods: 14 adult horses. Methods: Seven horses were administered BWE intragastrically and monitored for 11 hours. Tissue samples were obtained from the right ventral, left ventral, and right dorsal colons (RVC, LVC, and RDC, respectively) of the 7 BWE-treated and 7 control horses. Tissue samples were examined via light microscopy, and the extent of hemorrhage, edema, and gran...
Knych HK, Steinmetz SJ, McKemie DS.The anti-anxiety and calming effects following activation of the GABA receptor have been exploited in performance horses by administering products containing GABA. The primary goal of the study reported here was to describe endogenous concentrations of GABA in horses and the pharmacokinetics, selected pharmacodynamic effects, and CSF concentrations following administration of a GABA-containing product. The mean (±SD) endogenous GABA level was 36.4 ± 12.5 ng/mL (n = 147). Sixteen of these horses received a single intravenous and oral dose of GABA (1650 mg). Blood, urine, and cerebrospin...
Spallek A, Recknagel S, Breuer J, Koeller G, Schusser GF.The use of laxatives is crucial in the treatment of horses with large colon impaction. To reach the impacted mass, the laxative must leave the stomach and pass through the small intestine. The aim of this study was to determine whether the most frequently used saline and lubricant laxatives influence gastric emptying. Six fasted normal adult Warmblood horses were used in a randomized study design with five laxative trials (1.8% sodium sulfate [1.8% Na2SO4], 4.2% magnesium sulfate [4.2% MgSO4], mineral oil [MOil], 25% sodium sulfate [25% Na2SO4], 25% magnesium sulfate [25% MgSO4]) and two trial...
Timko K.Inflammatory bowel disease (IBD) in the horse encompasses a group of infiltrative gastrointestinal disorders resulting in malabsorption, maldigestion, weight loss, colic, and sometimes diarrhea. The type of IBD can be classified as granulomatous, lymphocytic-plasmacytic, or eosinophilic enterocolitis. The diagnosis of IBD in equids is based on consistent clinical signs and clinicopathologic findings in conjunction with confirmatory histopathology from a gastrointestinal biopsy. Treatment usually consists of a combination of immunosuppressive medications, anthelmintics, and dietary modification...
Nelson GR, Mama KR, Weiner D, McKemie DS, Kass PH, Steinmetz SJ, Knych HK.This study describes the pharmacokinetics and pharmacodynamics, including antinociceptive effects, of a transdermal buprenorphine solution in horses. It was hypothesized that transdermal application would lead to sustained blood concentrations and antinociceptive effects with fewer adverse effects compared with intravenous (IV) injection. Methods: Prospective nonrandomized four-part parallel experimental study. Methods: A group of eight horses (three mares and five geldings) aged 6-12 years. Methods: Horses were administered incremental doses of 15, 30 and 45 μg kg of buprenorphine transderma...
Tyrnenopoulou P, Tsilipounidaki K, Florou Z, Gkountinoudis CG, Tyropoli K, Starras A, Peleki C, Marneris D, Arseniou N, Lianou DT, Katsarou EI....The objectives of this study were (a) to detect zoonotic gastrointestinal pathogens in faecal samples of horses using the FilmArray GI Panel and (b) to identify variables potentially associated with their presence. Faecal samples collected from 224 horses obtained during a countrywide study in Greece were tested by means of the BioFire FilmArray Gastrointestinal (GI) Panel, which uses multiplex-PCR technology for the detection of 22 pathogens. Gastrointestinal pathogens were detected in the faecal samples obtained from 97 horses (43.3%). Zoonotic pathogens were detected more frequently in samp...
Stewart AS, Kopper JJ, McKinney-Aguirre C, Veerasamy B, Sahoo DK, Freund JM, Gonzalez LM.Gastrointestinal disease is a leading cause of death in mature horses. A lack of in vitro modeling has impeded the development of novel therapeutics. The objectives of this study were to develop and further characterize a small intestinal monolayer cell culture derived from equine jejunum including establishing normal measurements of intestinal permeability and restitution. Three-dimensional enteroids, derived from postmortem sampling of equine jejunum, were utilized to develop confluent epithelial monolayers. The presence of differentiated intestinal epithelial cell types and tight junctions ...
Delvescovo B, Chevalier JM, Campoy L, Cercone M.To describe a technique for ultrasound-guided celiac plexus block in horses and characterize its effect on intestinal motility in healthy horses. Methods: This study was conducted from January 2022 through June 2022. In phase 1 (dye study), an ultrasound-guided technique was optimized, and dye deposition around the celiac plexus branches was evaluated via postmortem dissection in 6 horses. In phase 2 (experimental study), 6 healthy horses were fasted and sedated with 0.6 mg/kg xylazine, IV (experiment 1). After a washout period, the ultrasound-guided celiac plexus block with lidocaine 1% (1.3 ...
de Freitas MG, Dos Santos GH, Silva DLZ, Costa TD, Borges DGL, Reckziegel GH, Cleveland H, do Nascimento Ramos CA, Pereira FB, de Almeida Borges F.The strategic control of equine gastrointestinal nematodes is based on epidemiology. The aim is the reduction of the population of parasites as a whole in the hosts and environment while seeking the number of treatments that achieves the balance between not risking animal health and not exerting selection pressure for resistant parasites. This is the first study in a tropical region to assess a strategic control protocol for equines. The study was conducted in the municipality of Anastácio in the state of Mata Gross do Sul, Brazil, over a two-year period from April 2021 to March 2023, involvi...
Kelly RF, Galbraith E, Zahid O, Chaundhry U, Sargison N.Grazing animal species kept in zoological collections can be at risk of significant gastrointestinal nematode (GIN) infections. Little work has been undertaken to understand GIN species dynamics within co-grazed hosts. This study aimed to describe the species diversity of GINs found in faeces of grazing animals in a Scottish zoological collection. Methods: At a single time-point, freshly voided faecal samples were collected randomly from horses, sheep, goats, alpacas and deer. Faecal worm egg counts (FWECs) were conducted using a saturated saline centrifugal flotation cuvette technique. The ne...
Wunderlich G, Bull M, McGilchrist N, Zhao C, Ross T, Rose M, Chapman B.The equine gut microbiome is a complex and dynamic ecosystem, housing a diverse consortium of bacteria and anaerobic fungi (AF) capable of breaking down complex plant matter and converting it into vital energy sources for their host. The aim of this study was to broaden our current understanding of bacterial and AF diversity in the equine hindgut and how it differs between cohorts and responds to dietary shifts. Results: Faecal samples were collected from 48 horses and the bacteriome and anaerobic mycobiome analysed using long-read amplicon sequencing. Samples were collected from racehorses (R...
Maldonado Moreno N, Alves Moreira J, Araujo De Oliveira L, Sanches Gontijo A, Castilho Baldi ML, Rocha Wenceslau R, Beier SL.A multimodal approach is recommended to optimize perioperative pain control in animals, although opioid use in horses remains limited due to the risks of central nervous system (CNS) stimulation and reduced intestinal motility. A group of 19 healthy, male, mixed-breed horses were divided into two groups and medicated with acepromazine (0.05 mg kg) and detomidine (10 µg kg), with methadone (0.05 mg kg) (ADM) or saline (ADS) administered intravenously (IV). Physiological variables, intestinal motility, gastric distention, and facial pain (EQUUS-FAP) were evaluated one day before (DB), before th...
