Gastric Ulceration - Horse
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This article is still under construction. |
| Also known as: | Gastroduodenal ulceration Equine Gastric Ulcer Syndrome |
Description
Prevalence
Racehorses 80-100% (Hammond et al 1986, Vatistas et al 1994 and 1997, Murray et al 1996) Show horses 60% (McClure et al 1999) Ponies 78% (MacAllister et al 1982) Endurance 67% (Pieto et al 2004)
Signalment
Foals and young horses in training
Pathophysiology
NOT associated with Helicobacter pylori and not typically associated with Gasterophilus
Risk Factors
Housing, stress, boredom, training, diet Feeding practices:
- Grain and pelleted feed asssociated with increased serum gastrin (Smyth et al 1988)
- Eating behaviour (grazing vs feeds)
- Feed constituents (alfalfa)
- Individual variability
Exercise and training
- Strenuous exercise stimulates gastrin release which has effects on HCL secretion, gastric emptying, gastric blood flow
Clinical syndrome
Often asymptomatic, may see:
- Poor appetite
- Dullness
- Change in attitude
- Reduced performance
- Reluctance to train
- Poor condition
- Weight loss
- Diarrhoea
- Low-grade colic
- Excessive recumbency
- Bruxism (in foals only and almost pathognomonic)
Foals with outflwo obstruction will dveelop reflux after suckling or marked reflux even with limited to no sukcling if the duodenal obstruction is distal to the common biel duct.(Sanhcez)
Diagnosis
Presumptive on clinical signs and response to treatment (Sanchez) Definitive diagnosis requires endoscopy (cannot do in foals as need to starve prior to exam)
Laboratory tests
No known laboratory markers, attempts to detect occult blood in faeces unreliable in horse. Other tests need further evaulationfor senstivty and sepcificity (Sanchez): Urine (93) and blood (94) sucrose absorption testing have been evauated a sameasure of gastric mucosal permeability (Sanchez) Serum alpha1-antitrypsin was detectable more frequnetly infoals with gastrci ulceration (95 in Sanchez)
Endoscopy
Performed under mild sedation in standing horse or foal (Sanchez) Duodenoscopy is most specific diagnostic method but is technically me chanllenegng than gastrocopy EGUS Lesion Scoring System publsihed based on consens by Equine Gastric Ulcer Council(2 in Sanchez)
| Lesion Grade | Description |
| Grade 0 | Intact epithelium with no appearance of hyperaemia or hyperkeratosis |
| Grade 1 | Intact mucosa with areas of reddening or hyperkeratosis (squamous) |
| Grade 2 | Small single of multifocal lesions |
| Grade 3 | Large single or multifocal lesions or extensive superficial lesions |
| Grade 4 | Extensive lesions with areas of deep ulceration |
Diffuse reddeing or inflammation may be only lesion seen in cases of early duodenal disease In older foals with GDUD, detection ofgastrci outflow obsturction is critical to therapeutic plan and appropriate prognosis (Sanchez)
Minimum endoscope length of two metres and 2.8-3.0 metre instruments are required for duodenoscopy A 3 mtre endoscope allows visualization of stomach, pyrlorus and proximal duodenum (Sanchez) Shorter scopes permit investigation fo gastric body and fundus only (Sanchez) Maximum external diameter of 9mm for neonates (Sanchez) Foals - lesions mainly in glandular epithelium Adults - margo plicatus and squamous epithelium
Abdominal radiography without contrast in foals with outflow obsturction typically rveeals very disticnt enlarged, gas-filled stomach. Liquid barium contrast will either have markedly delayed (with incomplete obstruction) oir no (complete onsbtruction) outflow. (Sanchez)
Pathology
Treatment
Proton pump inhibitors: only omeprazole (Gastroguard) is licensed for horses. Given PO once daily (4mg/kg) for 3-4 wks, most effective drug at controlling HCl secretion (decreases basal and stimulated release). Expensive and not absorbed in foas with diarrhoea Histamine H2 receptor antagonists:
- ranitidine 7mg/kg TID for 3-4wks
- cimetidine 25mg/kg QID for 3-4wks (cheaper but less effective so must be given more frequently)
Gastric protectants: sucralfate 10-20mg/kg TID for 2-4wks Antacids: magnesium and aluminium hydroxides (NOT recommended as have massive rebound effect)
Prognosis
Complications:
- Recurrence if management not altered
- Perforation and peritonitis (rare - foals)
- Pyloric stenosis (rare - foals)
Prevention
Gastroguard at lower dose (1-2mg/kg) daily for 3-4wks (100, 107-109 in Sanchez) Prophylaxis in foals controversial as gastric acidity may be protective against bacterial translocation (Sanchez). It may be beneficial in foals receiving substantial doses of NSAIDs for orthopaedic pain (Sanchez) Management: diet, training, exercise, stress (company, toys) Pasture turnout and continuous access to high quality forage especially alfalfa (Sanchez)
References
Gastric Ulceration - all species
- Affects the pars oesophagea (margo plicatus) in adults and foals.
- Due to parasites - Gasterophilus (Bots).
- Bots are not as common as they once were.
- Look like big pink maggots.
- Killed by Ivermectin.
- Gasterophilus leave large ulcers in glandular regions of the stomach.
- Ulcers / erosions are quite deep.
- The parasites are believed to be non-pathogenic, but in large numbers they probably produce some discomfort and poor growth.
- Carcinoma can also produce ulceration in the stomach of the horse as, in other species.
- In foals, the glandular area may sometimes be affected.
- This may be e.g. stress-related, or due to used of NSAIDs.