1	Diseases of the Stomach
2	Equine Gastric Ulcer Syndrome
3	Prevalence of Equine Gastric Ulcer Syndrome (EGUS) 60% to 93% in performance horses 25% to 50% in foals
4	EGUS: Public Perceptions Telephone Survey conducted in 2003, of 300 performance horse owners
5	Impact of EGUS on Adult Horses Results in poor body condition Can disrupt training Can impair performance Can cause colic Can have severe complications duodenal strictures
6	Impact of EGUS on Foals Gastric outflow obstruction Esophagitis Chronic ulceration Perforation (rupture) & peritonitis
7	The Stomach of the Horse
8	Compartments of the Equine Stomach
9	Cause of EGUS: Aggressive Factors Overpowering Defensive Factors Gastric lining damage occurs when: Aggressive (acid, pepsin, bile, organic acids) factors overpower Defenses (bicarbonate, mucus) of gastric mucosa Squamous mucosa lining lacks these defenses
10	Risk Factors for EGUS: Training/Racing Intensive exercise Reduced blood flow to the stomach lining? Increased gastric acidity? Altered eating behavior?
11	Acids forced into the proximal stomach
12	Risk Factors for EGUS: Feeding Feeding management Low prevalence of ulcers in horses at pasture
13	Risk Factors for EGUS: Feeding Decreased acid when roughage available Increased serum gastrin when fed concentrates (grains & sweet feeds) Intermittent feed deprivation = gastric ulcers Stall confinement = gastric ulcers Feeding alfalfa hay may help!
14	Gastric Acidity Profile: No Feed
15	Gastric Acidity Profile: Grass Hay
16	Hydrochloric Acid-Induced Ulcers Gastric acidity is high in empty stomach Intermittent feed deprivation Lesions form in squamous mucosa No lesions form in glandular mucosa Lesions prevented by ranitidine (Zantac®)
17	Risk Factors for EGUS: Stress Physical stress Illness Painful musculoskeletal disorder Behavioral stress Stall confinement Transport Unfamiliar environment, social regrouping
18	Risk Factors for EGUS: Non-Steroidal Anti-Inflammatory Drugs Phenylbutazone & Flunixin Meglumine and other NSAIDs Associated with ulcers throughout the intestinal tract (Cecum & Colon) Inhibit prostaglandins, interrupting mucosal blood flow and mucus Local toxicity
19	Clinical Signs of EGUS in Adult Horses Poor appetite Poor body condition Attitude changes Decrease in performance Mild to moderate colic
20	Clinical Signs of EGUS in Foals Poor appetite or intermittent nursing Colic Poor body condition Frequently lies on back Bruxism (grinding of teeth) Excessive salivation (Ptylism) Diarrhea
21
22	How can you tell that a Horse has EGUS? (Diagnosis) Clinical signs are suggestive of, but not specific for, EGUS Lab: Mild anemia Response to treatment can be useful Gastric endoscopy is only definitive diagnostic tool
23	Endoscopic Evaluation Endoscope quality & dimensions 9 ft long Small diameter Patient preparation Experience
24	Endoscopic Evaluation: Adults
25	Endoscopic Evaluation: Adults (cont’d)
26	Endoscopic Evaluation: Foals
27	Endoscopic Evaluation: Foals (cont’d)
28	Treatment of EGUS Eliminate clinical signs Promote healing Prevent complications Prevent recurrences
29	There Are Two Compatible Approaches to Treatment Management modifications Medical therapy-approaches that have been used Control gastric acid Mucosal protectants
30	Traditional Management Modifications Reduce level of training
31	Traditional Management Modifications Diet modifications Limit periods of fasting Increase roughage pasture turnout (green grass) free choice hay Alfalfa hay-dietary antacid Reduce grain/concentrates
32	Dietary Management Fresh Rice Bran and Rice Bran Oil Contains surface active phospholipids and cytoprotective factors that maintain health of the stomach lining Rancidity can be a problem Produces ketoaldehydes which are ulcerogenic Steam pasteurization can help decrease potential for rancidity Storage in refrigerator
33	Management Modifications Limit stressful events Long-term stall confinement Trailering Overcrowding
34	Organic Acids (VFAs or SCFAs) High Concentrate Diets Acetic, Butyric, Propionic, and Valeric Acids Byproducts of carbohydrate fermentation in the stomach Synergistic with HCl May lead to non-glandular ulcers Increased VFA’s with increased grain
35	Medical Management of EGUS Neutralizing agents Antacids Antisecretory agents Histamine H₂ receptor antagonists Prostaglandin analog Acid pump inhibitors Others (antibiotics, neutriceuticals)
36
37	GASTROGARD^® (Omeprazole) New oral-paste formulation of omeprazole developed specifically for horses Well-studied, effective, and safe therapy for EGUS Approved for use in horses, March 1999
38	Ulcer Treatments Act at Different Sites
39	GastroGard^® Allows Healing/Improvement of Ulcers
40	GastroGard^® Advantages Profound gastric acid suppression Prolonged duration of action Once-daily dosing Well studied in horses No reported treatment-related health problems in equine trials Prevents ulcer recurrence Can maintain training program Approved for use in horses (GASTROGARD^®)
41	GastroGard^®: Disadvantages No IV formulation available in US
42	UlcerGardÔ Prevention of ulcers Non-perscription strength of GastrogardÔ Sold through veterinarians
43	Histamine H₂ Receptor Antagonists Zantac® (ranitidine), Tagamet® (cimetidine) Competitive inhibition of the interaction of histamine with parietal cell Dose-dependent inhibition of gastric acid secretion
44	Histamine H₂ Receptor Antagonists: Advantages & Disadvantages Availability Low cost (generic) Zantac® has been shown to significantly inhibit gastric acid secretion in horses Must be administered 3X daily
45	Antibiotic Treatment Amoxicillin, metronidazole, clarithromycin, bismuth compounds, etc. Primarily used in humans with Helicobacter pylori H. pylori has been associated with the stomach of horses, but not EGUS Antimicrobials may be used in horses with resistant EGUS
46	Recent Studies on Helicobacter spp. Helicobacter specific DNA isolated from horse stomachs 2 horses with squamous erosions 1 horse with glandular erosions ACVIM Forum-Dallas (May 2002)
47	Feed Supplements (Neutriceuticals) NeighLox^®(Kentucky Performance Products) Antacid and Coating Agents: Aluminum Phosphate, Calcium Carbonate Dihydroxy-Aluminium Sodium Carbonate Labeled for prevention of heartburn No studies in horses to prove or disprove Probably does not cause any harm
48	Feed Supplements (Neutriceuticals) G.U.T (Uckele Health & Nutrition) Gastric ulcer transnutrient for horses with ulcers Ingredients Gelatin Lactobacillus acidophilus, L. lactis Feed 15 grams (1 scoop) twice daily in horses with ulcers No studies proving efficacy
49	Feed Supplements (Neutriceuticals) TractGard (Foxden Equine) Equine GI rehydrator, antacid, digestaid, and electrolyte salt Ingredients (1 to 2 scoops daily) Calcium carbonate, Sodium sequiscarbonate, KCl, MgSO₄, distiller’s grain, yeast, and linseed meal No studies on efficacy
50
51	Conclusions- General EGUS is a major cause of illness 60-93% of performance horses have EGUS Impacts health, performance, economics Occurs when aggressive factors overpower gastric defenses
52	Conclusions- General Diagnosis requires endoscopy Presumptive diagnosis made based on clinical signs following complete diagnostic evaluation Treatment: management and medical interventions
53	Conclusions- Treatment Zantac®-healing 3X daily treatment Dietary supplements-not tested GastroGard® (omeprazole) Only FDA approved treatment Provides potent, long-lasting gastric acid suppression in horses (once daily administration) 92% to 99% improvement in ulcer scores in trials and a wide safety margin UlcerGardÔ Prevention of Ulcers
54	Duodenal Ulcers/Stricture Part of EGUS (more commonly in foals) Similar pathogenesis Similar clinical signs Usually associated with bruxism, ptylism, and diarrhea (occurs most often in foals) Delayed gastric emptying Associated with esophageal ulcers
55	Duodenal Ulcers/Strictures Diagnosis Clinical signs Duodenoscopy Radiology gastric emptying with barium swallows (liquid meal=30 minutes) Necropsy
56	Duodenal Ulcers/Strictures Treatment Omeprazole (4 mg/kg, PO, Q24h, 28 days) Omeprazole (0.5 mg/kg, IV, Q24h) Ranitidine (6.6 mg/kg, PO, Q8h) Surgery-Gastrojejunostomy (foals only?)
57	Gastric Neoplasia Uncommon in older horses Squamous cell carcinoma, most common Others: lymphosarcoma, adenosarcoma Arises from squamous mucosa and metastasizes to the abdominal cavity and viscera and/or extends up the esophagus Clinical signs: Chronic weight loss Anemia Naso-gastric reflux Colic
58	Gastric Neoplasia Diagnosis Clinical Signs Endoscopy (definitive) Abdominal ultrasound Necropsy Treatment: None Prognosis: Grave
59	Gastric Impaction Infrequent cause of Colic in horses Dry feed material and decreased water intake May occur during winter when dry hay is fed and water intake is lower Diagnosed at surgery in horses with colic Endoscopic examination Treatment with dioctyl sodium succinate (DSS) 5% solution via NG tube in 4 to 6 L fluid Lavage at surgery, resolve in 24 – 48 hours