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==Diagnosis==
==Diagnosis==
A presumptive diagnosis can be based on clinical signs and response to therapy,<ref name="Sanchez">Sanchez, L.C (2010) 'Diseases Of The Stomach' in Reed, S.M, Bayly, W.M. and Sellon, D.C (2010) '''Equine Internal Medicine''' (Third Edition), Saunders, Chapter 15.</ref> however, a definitive diagnosis requires visualisation of the stomach. This can be achieved in the live horse using endsocopy or, alternatively, at post-mortem.(Nadeau 2009)
''EGUS was recently discussed at the 2010 Annual meeting between the Equine Insurers Forum (EIF) and the British Equine Veterinary Association (BEVA). The EIF maintained that in order to support claims for the long term costs associated with treatment of EGUS, there would be a requirement for veterinary surgeons to make a definitive diagnosis prior to prescribing omeprazole.(BEVA)''
(Nadeau 2009)
''EGUS was recently discussed at the 2010 Annual meeting between the Equine Insurers Forum (EIF) and the British Equine Veterinary Association (BEVA). The EIF maintained that in order to support claims for the long term costs associated with treatment of EGUS, there would be a requirement for veterinary surgeons to make a definitive diagnosis prior to prescribing omeprazole.(BEVA)''
===Endoscopy===
===Endoscopy===
(cannot do in foals as need to starve prior to exam)
ante mortem using a 2.5–3.0 m endoscope and utilising an established scoring system (Nadeau 2009)
Endoscopic equipment can be grouped into 2 categories: fibreoptic and video.
Flexible endoscopes: for mature equine gastric endoscopy, a minimum working length of 200 cm is required. However, a 280-300 cm long endoscope is required to perform duodenoscopy in mature individuals. A working length of 110 cm with an outer diameter of 10 mm (human gastroscope) is sufficient to reach the stomach of foals up to age 30-40 days.
Flexible endoscopes: for mature equine gastric endoscopy, a minimum working length of 200 cm is required. However, a 280-300 cm long endoscope is required to perform duodenoscopy in mature individuals. A working length of 110 cm with an outer diameter of 10 mm (human gastroscope) is sufficient to reach the stomach of foals up to age 30-40 days.
Fibreoptic endoscopic equipment uses glass-fibre bundles to transmit light to the area to be viewed and transmit this image to an eyepiece. The image is magnified by a lens system within the eyepiece. This is important in alimentary endoscopy, since 150 W lamps used in most portable light sources provide poor illumination of a horse’s stomach. More powerful light sources are available (up to 300 W) but become larger and less portable as the lamp intensity increases. The quality of the fibreoptic instrument is determined largely by its image resolution, which is related directly to the number of optical fibres.
Fibreoptic endoscopic equipment uses glass-fibre bundles to transmit light to the area to be viewed and transmit this image to an eyepiece. The image is magnified by a lens system within the eyepiece. This is important in alimentary endoscopy, since 150 W lamps used in most portable light sources provide poor illumination of a horse’s stomach. More powerful light sources are available (up to 300 W) but become larger and less portable as the lamp intensity increases. The quality of the fibreoptic instrument is determined largely by its image resolution, which is related directly to the number of optical fibres.
Videoendoscopic systems use glass-fibre bundles to transmit light, but use a charge-coupled device (CCD) chip to transmit the image. Generation of the light source (300 W) and processing of the CCD-generated electronic signal occurs in the endoscope’s processor.
Videoendoscopic systems use glass-fibre bundles to transmit light, but use a charge-coupled device (CCD) chip to transmit the image. Generation of the light source (300 W) and processing of the CCD-generated electronic signal occurs in the endoscope’s processor.
Oesophagogastroscopy may be performed at the facility where the horse is normally housed. The horse must be held off feed for 6-8 h before oesophagogastroscopy to allow time for the stomach to empty and permit visualisation of the mucosa. The procedure is usually performed approximately 5 min after i.v. sedation with xylazine (Rompun), 0.6-0.8 mgkg bwt. (Orsini)
Oesophagogastroscopy may be performed at the facility where the horse is normally housed. The horse must be held off feed for 6-8 h before oesophagogastroscopy to allow time for the stomach to empty and permit visualisation of the mucosa. The procedure is usually performed approximately 5 min after i.v. sedation with xylazine (Rompun), 0.6-0.8 mgkg bwt. (Orsini)
Minimum endoscope length of two metres and 2.8-3.0 metre instruments are required for duodenoscopy A 3 metre endoscope allows visualization of stomach, pylorus and proximal duodenum (Sanchez) Shorter scopes permit investigation of 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
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
Performed under mild sedation in standing horse or foal (Sanchez)
Performed under mild sedation in standing horse or foal (Sanchez)
Duodenoscopy is most specific diagnostic method but is technically me chanllenegng than gastrocopy
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)
EGUS Lesion Scoring System publsihed based on consens by Equine Gastric Ulcer Council(2 in Sanchez)
The EGUS Council has adopted a lesion grading system that:
Is simple and straightforward
Can be applied to the squamous and glandular mucosal linings of the equine stomach
Note that no mention of bleeding is made in assigning lesion grades, because bleeding does not determine lesion severity. Small superficial erosions (Fig 3) may bleed, whereas deep ulcers may not have active haemorrhage at the time of endoscopic examination.(EGUC)
|-
|-
|Grade 0
|Grade 0
|Intact epithelium with no appearance of hyperaemia or hyperkeratosis
|Intact epithelium with no appearance of hyperaemia (reddening) or hyperkeratosis (yellowing of the squamous mucosa)
|-
|-
|Grade 1
|Grade 1
|Extensive lesions with areas of deep ulceration
|Extensive lesions with areas of deep ulceration
|}
|}
While these systems are useful for assessing the extent of disease and monitoring response to treatment, little work has been done to correlate gross observations with the histological picture. Lesions that appear alike grossly and receive similar numerical scores may have dissimilar histological appearances and underlying pathogeneses.(Martineau 2009)
The endoscopist may underestimate the n u m b e r of gastric ulcers and may not be able accurately to p redict the severity or depth of those ulcers present in the n o n g l a n d u l a r equine stomach. Furt h e r m o re, the endoscopist may miss glandular gastric ulcers. (Andrews 2002
Diffuse reddeing or inflammation may be only lesion seen in cases of early duodenal disease
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)
In older foals with GDUD, detection ofgastrci outflow obsturction is critical to therapeutic plan and appropriate prognosis (Sanchez)
===Radiography===
===Radiography===
Furthermore, serum 1-antitrypsin was present in 44/47 foals with gastric ulcers compared to only 3/22 healthy foals (Taharaguchi et al. 2007). 1-antitrypsin may be released into serum from damaged gastric tissue, but more research is needed to validate this serum marker as a diagnostic test for EGUS.(Nadeau 2009)
Furthermore, serum 1-antitrypsin was present in 44/47 foals with gastric ulcers compared to only 3/22 healthy foals (Taharaguchi et al. 2007). 1-antitrypsin may be released into serum from damaged gastric tissue, but more research is needed to validate this serum marker as a diagnostic test for EGUS.(Nadeau 2009)
Other diagnostic methods include measuring urine and plasma sucrose concentration (sucrose permeability tests) (O’Conner et al. 2004; Hewetson et al. 2006). However, methods for measuring sucrose require sophisticated analysis equipment, which may not be practical for clinicians in the field.
(Nadeau 2009)
===Pathology===
===Pathology===