Topic:Stomach
The equine stomach is a complex organ responsible for the initial stages of digestion in horses. It is divided into two main regions: the non-glandular (squamous) region and the glandular region, each with distinct functions and susceptibilities to conditions such as ulcers. The stomach's acidic environment aids in breaking down food particles, while enzymes initiate the digestion of proteins. The equine stomach is adapted for continuous grazing, with relatively small capacity and rapid emptying into the small intestine. This page aggregates peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, and common disorders of the horse's stomach, as well as their implications for equine nutrition and health management.
A device and technique for gastrointestinal lavage in the horse. A device and technique for intra-operative gastro-intestinal lavage was developed to remove ingesta from the stomach, large intestine and caecum of horses. The Gastro-Intestinal Lavage System (GILS) is composed of a nozzle connected to both water under pressure and suction. Water jets across an intake portal in the nozzle, breaks up food and debris within the nozzle and is evacuated under negative pressure into the aspirating tube which is connected to a collection drum. The GILS nozzle was introduced at the pelvic flexure through a sterile enterotomy cuff and plastic sleeve. Water was first a...
Regional gastric pH measurement in horses and foals. The pH of the gastric mucosal surface and gastric content was measured in 18 foals (mean age: 20 days) and 27 horses (mean age: 2.9 years) with a pH electrode passed through an endoscope biopsy channel. A reference electrode was attached to a shaved area on the neck. pH Measurements of the gastric mucosal surface at the dorsal squamous fundus (SF), squamous mucosa adjacent to the margo plicatus (MP), glandular fundus (GF) and the fluid or feed contents of the stomach were recorded in duplicate for each animal. In adult horses, the SF pH was greatest (5.46 +/- 1.82), with a decreasing pH ventra...
Effects of cimetidine and ranitidine on basal gastric pH, free and total acid contents in horses. The basal gastric pH, free and total acid contents from five adult horses were determined at two-hour intervals for six- to eight-hour periods. The basal gastric pH, free and total acid contents varied from 2.14 +/- 0.08 to 2.41 +/- 0.14, 28.63 +/- 8.27 to 17.89 +/- 2.86 mmol litre-1 and 41.38 +/- 9.72 to 37.38 +/- 3.70 mmol litre-1, respectively. Cimetidine (8.8 mg kg-1 orally) and ranitidine (2.2 mg kg-1 orally) increased the basal gastric pH to above 3.6 (P less than 0.05) with a concomitant reduction of 75 per cent and 75 to 100 per cent in the basal gastric free acid content, respectively...
World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for evaluating the efficacy of equine anthelmintics. These guidelines have been designed to assist in the planning, operation and interpretation of studies which would serve to assess the efficacy of drugs against internal parasites of horses. Although the term anthelmintic is used in the title and text, these guidelines include studies on drug efficacy against larvae of horse bot flies, Gasterophilus spp, which are non-helminth parasites commonly occurring in the stomach of horses. The advantages, disadvantages and application of critical and controlled tests are presented. Information is also provided on selection of animals, housing, feed, do...
Megaesophagus and aspiration pneumonia secondary to gastric ulceration in a foal. A 3-month-old foal with a history of persistent fever and leukocytosis was found to have pneumonia, ulceration of the squamous portion of the stomach, and dilatation of the distal portion of the esophagus. The foal was euthanatized and necropsied. The distal portion of the esophagus was severely dilated, and there was severe ulceration and mural thickening of the stomach at the cardia. Because of the severe gastric ulceration and mural thickening, the gastroesophageal junction was fixed in an open position, permitting gastroesophageal reflux. The megaesophagus and pneumonia were considered to ...
Chronic flunixin meglumine therapy in foals. Effects of a therapeutic dose of flunixin meglumine on gastric mucosa of horse foals were determined by endoscopy, double-contrast radiography, and gross and histologic examinations. Foals were administered 1.1 mg of flunixin meglumine/kg of body weight, PO/day for 30 days in an encapsulated form that was divided into 2 doses/day (group 1; n = 3) or by IM injection once a day (group 2; n = 7). Three control foals (group 3; n = 3) were administered capsules (n = 1) containing dextrose powder or IM injections (n = 2) of vehicle solution without flunixin meglumine. All 3 groups-1 foals given flun...
Effect of ranitidine on gastric acid secretion in young male horses. Gastric cannulas were placed surgically in 5 young male horses. After a 2-week recovery period, horses were studied once a week. Horses were fasted for 24 hours, and gastric fluid output was collected for 5 continuous hours. Volumes were recorded every 15 minutes, and pH and hydrogen ion concentration were determined in an aliquot from each period. In 10 basal experiments, using 5 horses, volume, pH, and hydrogen ion concentration were continuously variable. Mean acid output was 45.1 +/- 2.02 microEq/15 min/kg (mean +/- SEM). In 6 experiments, using 3 horses, 0.5 mg of ranitidine/kg of body we...
Seasonal occurrence and distribution of Gasterophilus intestinalis and Gasterophilus nasalis in the stomachs of equids in Texas. Stomachs of 271 horses and ponies from 2 sources were evaluated for the presence of Gasterophilus intestinalis and G nasalis larvae, through 2 overlapping 12-month periods of bot fly activity in southern Texas. Equids (n = 140) from one source had nearly 96% of their stomachs infected, whereas equids (n = 131) from another source had 44% of their stomachs infected by Gasterophilus spp. Seasonal dynamics of the bot infection indicated the highest average number of bot larvae per infected stomach occurred in the winter and spring. The smallest average number of bots per infected stomach occurred...
Two cases of equine primary gastric impaction. The clinical details of two cases of equine primary gastric impaction are described and the syndromes of gastric impaction and dilatation are discussed. Both cases of gastric impaction were successfully treated by gastrotomy and evacuation of the gastric contents.
Common internal parasites found in the stomach, large intestine, and cranial mesenteric artery of thoroughbreds in Kentucky at necropsy (1985 to 1986). A total of 278 Thoroughbreds (less than 1 to 31 years old) were examined at necropsy (July 9, 1985, to Feb 2, 1986) in Kentucky for various internal parasites. Examination was not made of all the horses for each of the parasites. Specific parasites recovered from the stomach of foals (n = 30) and yearlings and older horses (n = 96) and percentage (in parentheses) of each age category infected, respectively, were as follows: Gasterophilus intestinalis 2nd instar (53% and 32%) and 3rd instar (37% and 24%); G nasalis 2nd instar (7% and 8%) and 3rd instar (7% and 10%); Habronema spp immature (7% a...
Surgical repair of a partial gastric rupture in a horse. RUPTURE of the stomach is a common complication of
gastric impaction and intestinal reflux or of gastric distention.
After rupture, the general condition of the horse deteriorates
and death follows within a few hours (Tennant, Wheat and
Meagher 1972; McIlwraith 1982).
Dietz and Wiesner (1982) state that partial rupture of the
stomach may result in severe blood loss with circulatory
collapse. In this report a partial rupture of the stomach was
surgically repaired during exploratory laparotomy.
Gastroduodenal ulceration in foals. Gastroduodenal ulceration is becoming recognised as an important disease in foals during the first few months of life. Aetiopathogenesis is presumed to be similar to peptic disease in humans associated with back diffusion of hydrogen ions into the mucosa. Many factors have been incriminated as predisposing foals to ulceration but few have been proven. To date, use of non-steroidal anti-inflammatory agents has been the only documented cause of gastroduodenal ulceration in foals. The clustering of affected foals on certain farms suggests an infectious aetiology but attempts to identify a causati...
Gastroenterostomy for treatment of gastroduodenal ulcer disease in 14 foals. Gastroenterostomy was performed in 14 foals to treat gastric outflow obstruction caused by advanced gastroduodenal ulcer disease. The onset of excessive salivation and teeth grinding, without response to medical treatment, combined with endoscopic and radiographic evidence of gastric outflow obstruction, were indications for surgical intervention. Successful outcome in 5 foals was attributed to early diagnosis, patient stabilization, early surgical correction, and postoperative management including antibiotics and antiulcer medication.
Neostigmine methylsulfate delays gastric emptying of particulate markers in horses. Eight horses were allotted to 2 groups, each of 4 horses. All horses were given 100 plastic markers intragastrically via a nasogastric tube. One group of animals (control group) was not given medication after marker administration. The other group (test group) was given neostigmine methylsulfate (0.022 mg/kg of body weight) in the subcutaneous tissue at the time of marker administration and 30, 60, and 90 minutes later. All horses were killed 135 minutes after marker administration to locate the beads in the gastrointestinal tract. Gastric emptying of the markers was significantly delayed (P l...
Diagnosis of gastroduodenojejunitis and its surgical treatment by a temporary duodenocaecostomy. Gastroduodenojejunitis is a catarrhal inflammation of the stomach and proximal portion of the small intestine. Secondary overloading of the stomach occurs so that affected horses rapidly enter a state of hypovolaemic shock which is further complicated by the presence of toxins. The condition can occur in a mild or severe form. In mild cases, conservative treatment comprising intravenous electrolyte therapy and repeated gastric decompression is indicated and is usually successful. In severe cases surgical treatment creating duodenocaecal anastomosis has given good results. This should be carrie...
Fiberoptic gastroduodenoscopy in the horse. A method of fiberoptic gastroduodenoscopy and biopsy was developed for use in large horses. A 275 cm X 13.5 mm fiberendoscope was used to examine the stomach and proximal portion of the duodenum. Food was withheld for 24 to 48 hours before examination. In more than 50 horses, gastric and duodenal structures were easily visualized. A variety of lesions was detected, including parasitic lesions, gastric ulcers, gastric neoplasia, and pyloric stenosis. Mucosal biopsy specimens were obtained in selected cases.
Prevalence of some internal parasites recovered at necropsy of Thoroughbreds born in 1982 in Kentucky. A total of 89 Thoroughbreds, 14 to 333 days old (born in 1982), were examined at necropsy for certain internal parasites during a 1-year-period, Mar 1, 1982, to Feb 28, 1983. The eyes of 73 of the horses and the cranial mesenteric arteries of 71 were examined. Specific interest was on prevalence of parasites according to month of the year and age of the horses at necropsy. Parasites recovered (first month-last month infected horse found) were as follows: Thelazia lacrymalis (eyes) immature and mature (June - February); Habronema/Draschia (lungs) immature (May - September); Habronema muscae (st...
Immunocytochemical distribution of endocrine cells in the gastrointestinal tract of the horse. Endocrine cells immunoreactive for somatostatin, gastrin, glicentin, glucagon, secretin, cholecystokinin, motilin and neurotensin were identified immunocytochemically in the gastrointestinal mucosa of the horse. Somatostatin-, glicentin- and glucagon-immunoreactive cells were very numerous in the cardiac and fundic regions of the stomach, whereas most gastrin-immunoreactive cells were confined to the pyloric region. Somatostatin-immunoreactive cells also were detected in all portions of the small intestine while gastrin-immunoreactive cells were confined exclusively to the upper portion and gl...
Effectiveness of fenbendazole against later 4th-stage Strongylus vulgaris in ponies. Twelve pony foals (reared worm-free) were inoculated with Strongylus vulgaris. Approximately 8 weeks later, 4 of the foals were given fenbendazole (10% suspension) at a dosage rate of 10 mg/kg of body weight daily for 5 days and 4 foals were given the suspension at a dosage rate of 50 mg/kg daily for 3 days; the remaining foals were given a placebo. All treatments were administered by stomach tube. Fenbendazole was 99.6 and 97.9% effective in the 2 treatment groups, respectively, in eliminating later 4th-stage S vulgaris larvae located near the origin of major intestinal arteries. On microscop...
Nitrogen partitioning along the equine digestive tract. Twelve adult horses were fed a corn-oats-timothy hay diet containing 2.87% nitrogen (N) for 4 wk and were then killed. Fresh digesta samples were immediately harvested from the stomach, duodenum, jejunum, ileum, cecum, large colon, small colon, rectum and feces. Total N content of the digesta (on a dry matter basis) increased from the stomach (2.74%) to the duodenum (5.58%; P less than .01), decreased in the cecum (3.10%, P less than .01), remained constant through the large intestine and decreased in the feces (2.10%; P less than .01). High-speed centrifugation of wet digesta and low-speed ce...
Parasites in Kentucky Thoroughbreds at necropsy: emphasis on stomach worms and tapeworms. A total of 363 Thoroughbreds (62 males, 292 females, and 9 geldings), 1 to 26 years of age, were examined at necropsy for internal parasites for about a 12-month period from February 1981 through February 1982. Emphasis was on examining the stomach for nematodes and the small intestine and cecum for tapeworms. Parasites recovered from the stomach and infection rates were: Habronema spp--immature (24%), H muscae--adult (38%), Draschia megastoma--immature (13%), D megastoma--adult (62%), and Trichostrongylus axei--adult (4%); lesions caused by D megastoma were found upon gross observation in 58%...
Six cases of squamous cell carcinoma of the stomach of the horse. Six cases of squamous cell carcinoma of the stomach in horses seen at the New York State College of Veterinary Medicine are compared with 15 similar cases reported previously. Clinical signs included anorexia in all cases, emaciation, fever, anaemia and/or palpable abdominal masses in 3, colic in 2 and dysphagia in one case. Haematological studies revealed normochromic, normocytic anaemia in 3 and absolute neutrophilia in 5 cases. Peritoneal fluid analysis was performed in 4 cases and revealed slightly to moderately elevated total protein concentrations in 3 and a markedly elevated number of w...
[Artificial infestation of horses with the eggs of the stomach botfly (Gastrophilidae)]. 10 foals were artificially infected for the first time with eggs of Gastrophilus intestinalis, G. veterinus, G. haemorrhoidalis, G. inermis, G. nigricornis. 63 to 67% of the 1st stage larvae die in the first period of life after emergence from the egg, at the moment of invasion into the skin and at the beginning of the migration. In 40 to 45 years after the infection most larvae (73 to 82%), depending on their specific belonging, were found in the stomach, duodenum and rectum.