Changes

==Description==

==Description==

The term ''''Equine gastric ulcer syndrome (EGUS)'''' encompasses a number of disease complexes<ref>Merritt, A M (2009) Appeal for proper usage of the term ʻEGUSʼ: Equine gastric

The term ''''Equine gastric ulcer syndrome (EGUS)'''' encompasses a number of disease complexes<ref name="Merritt">Merritt, A M (2009) Appeal for proper usage of the term ʻEGUSʼ: Equine gastric

ulcer syndrome.  ''Equine Vet J'', 41(7):616.</ref> associated with ulceration of the oesophageal, gastric or duodenal mucosa<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref> in horses.  When such damage is caused by acidic gastric juice, the defect is described as a ''''peptic ulcer''''.<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref>  Ulceration of either or both<ref>Andrews, F.M, Bernard, W.V, Byars, T.D ''et al.'' (1999) Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 1:122-134.  In: 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> regions of the gastric mucosa is one of the most important problems of the equine stomach as it may limit performance<ref name="Bell">Bell, R.J, Mogg, T, Kingston, J.K (2007) Equine gastric ulcer syndrome in adult horses: a review.  ''N Z Vet J'', 55(1):1-12).</ref> and compromise welfare.<ref name="Martineau">Martineau, H, Thompson, H, Taylor, D (2009) Pathology of gastritis and gastric ulceration in the horse.  Part 1: Range of lesions present in 21 mature individuals.  ''Equine Vet J'', 41(7):638-644.</ref>  The non-glandular (proximal or orad) region of the equine stomach is lined by stratified squamous mucosa and a glandular mucosa lines the distal (aborad) portion.  The two regions meet abruptly at the '''''margo plicatus'''''<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>, adjacent to where most ulcers occur.<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref>  Damage to these regions occurs via differing pathophysiological routes and varies in severity from inflammation, to cellular death and sloughing causing disruption of the superficial mucosa ('''erosion'''), penetration of the submucosa down to the level of the ''lamina propria''<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref>('''ulceration'''),  full thickness ulceration ('''perforation''')<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> and potentially duodenal stricture.<ref name="Merck">Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial</ref> The occult nature of the disease typically precludes the observation of clinical signs until severe ulceration has developed.<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref>

ulcer syndrome.  ''Equine Vet J'', 41(7):616.</ref> associated with ulceration of the oesophageal, gastric or duodenal mucosa<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref> in horses.  When such damage is caused by acidic gastric juice, the defect is described as a ''''peptic ulcer''''.<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref>  Ulceration of either or both<ref>Andrews, F.M, Bernard, W.V, Byars, T.D ''et al.'' (1999) Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 1:122-134.  In: 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> regions of the gastric mucosa is one of the most important problems of the equine stomach as it may limit performance<ref name="Bell">Bell, R.J, Mogg, T, Kingston, J.K (2007) Equine gastric ulcer syndrome in adult horses: a review.  ''N Z Vet J'', 55(1):1-12).</ref> and compromise welfare.<ref name="Martineau">Martineau, H, Thompson, H, Taylor, D (2009) Pathology of gastritis and gastric ulceration in the horse.  Part 1: Range of lesions present in 21 mature individuals.  ''Equine Vet J'', 41(7):638-644.</ref>  The non-glandular (proximal or orad) region of the equine stomach is lined by stratified squamous mucosa and a glandular mucosa lines the distal (aborad) portion.  The two regions meet abruptly at the '''''margo plicatus'''''<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>, adjacent to where most ulcers occur.<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref>  Damage to these regions occurs via differing pathophysiological routes and varies in severity from inflammation, to cellular death and sloughing causing disruption of the superficial mucosa ('''erosion'''), penetration of the submucosa down to the level of the ''lamina propria''<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref>('''ulceration'''),  full thickness ulceration ('''perforation''')<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> and potentially duodenal stricture.<ref name="Merck">Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial</ref> The occult nature of the disease typically precludes the observation of clinical signs until severe ulceration has developed.<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref>

==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)

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.<ref name="Nadeau">Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref>

''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)''

''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.''

===Endoscopy===

===Endoscopy===

Oesophagogastroscopy or duodenoscopy can be performed under mild sedation (e.g. 0.6-0.8mg/kg xylazine(Orsini)) in the standing horse.  Of these, duodenoscopy is the more specific but more technically demanding method(Sanchez).  Endoscopic examination requires preparatory starving of the patient for 6-8hours (Orsini), eliciting a certain degree of stress.  As such, it is preferable not to carry out this technique in foals.  In adult horses, a minimum endoscope length of two metres is essential to visualize the gastric body and fundus.(Sanchez)  A 2.8-3.0 metre endoscope is needed to observe the gastric antrum, pylorus and proximal dudoenum.(Sanchez)  In either case, fibreoptic or videoendoscopic equipment can be used.(EGUC)

Oesophagogastroscopy or duodenoscopy can be performed under mild sedation (e.g. 0.6-0.8mg/kg xylazine<ref name="Orsini">Orsini, J (2000) Tutorial Article Gastric ulceration in the mature horse: a review. ''Equine Vet Educ'', 12(1):24-27.</ref>) in the standing horse.  Of these, duodenoscopy is the more specific but more technically demanding method.<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> Endoscopic examination requires preparatory starving of the patient for 6-8hours,<ref name="Orsini">Orsini, J (2000) Tutorial Article Gastric ulceration in the mature horse: a review. ''Equine Vet Educ'', 12(1):24-27.</ref> eliciting a certain degree of stress.  As such, it is preferable not to carry out this technique in foals.  In adult horses, a minimum endoscope length of two metres is essential to visualize the gastric body and fundus.<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> A 2.8-3.0 metre endoscope is needed to observe the gastric antrum, pylorus and proximal dudoenum.<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> In either case, fibreoptic or videoendoscopic equipment can be used.<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref>

Based on a consensus, the Equine Gastric Ulcer Council (EGUC) published an EGUS Lesion Scoring System which they claimed to be simple and applicable to both regions of the equine gastric mucosa(EGUC).  This last point has been debated, since most of the acquired data on gastric lesions refers only to the squamous mucosa(Merritt).  At the time of writing however, the EGUC system appears to be the most well established and useful in practice:  

Based on a consensus, the Equine Gastric Ulcer Council (EGUC) published an EGUS Lesion Scoring System which they claimed to be simple and applicable to both regions of the equine gastric mucosa.<ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS).  ''Equine Vet Educ'', 11(5):262-272.</ref> This last point has been debated, since most of the acquired data on gastric lesions refers only to the squamous mucosa.<ref name="Merritt">Merritt, A M (2009) Appeal for proper usage of the term ʻEGUSʼ: Equine gastric

ulcer syndrome.  ''Equine Vet J'', 41(7):616.</ref> At the time of writing however, the EGUC system appears to be the most well established and useful in practice:  

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Diffuse inflammation may be the only lesion observed in foals with early GDUD.(Sanchez)  In contrast to other scoring systems(MacAllistaer et al 1997), the EGUC approach does not include bleeding when assigning lesion grades.  The justification is that the 'snapshot' provided by endoscopy may by chance identify bleeding of superficial erosions whilst missing the intermittent haemorrhage of more severe lesions.(EGUC)  Endoscopy may assist in understanding the severity of the disease and assessing the therapeutic response, but it is not without disadvantages.  Ulcer severity may be underestimated, particularly in the squamous region and glandular ulcers may be missed altogether(Andrews 2002).  Lesions that appear grossly similar may have different grades on histopathology(Martineau 2009).  This is important as varying lesions may have different causes, requiring a range of treatment approaches.

Diffuse inflammation may be the only lesion observed in foals with early GDUD.<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> In contrast to other scoring systems(MacAllistaer et al 1997), the EGUC approach does not include bleeding when assigning lesion grades.  The justification is that the 'snapshot' provided by endoscopy may by chance identify bleeding of superficial erosions whilst missing the intermittent haemorrhage of more severe lesions. <ref name="EGUC">The Equine Gastric Ulcer Council (1999) Tutorial Article: Recommendations for the diagnosis and treatment of equine gastric ulcer syndrome (EGUS). ''Equine Vet Educ'', 11(5):262-272.</ref> Endoscopy may assist in understanding the severity of the disease and assessing the therapeutic response, but it is not without disadvantages.  Ulcer severity may be underestimated, particularly in the squamous region and glandular ulcers may be missed altogether(Andrews 2002).  Lesions that appear grossly similar may have different grades on histopathology.<ref name="Nadeau">Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref> This is important as varying lesions may have different causes, requiring a range of treatment approaches.

===Radiography===

===Radiography===

In older foals with GDUD, detection of gastric outflow obstruction via abdominal radiography is essential to treatment and prognosis.(Sanchez)  Liquid barium will demonstrate very delayed or no outflow depending on the degree of obstruction.  Without contrast medium, a large, gas filled stomach will be obvious.<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>.  The need to perform contrast radiography must be weighed against the stress it would place upon the foal.

In older foals with GDUD, detection of gastric outflow obstruction via abdominal radiography is essential to treatment and prognosis.<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> Liquid barium will demonstrate very delayed or no outflow depending on the degree of obstruction.  Without contrast medium, a large, gas filled stomach will be obvious.<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>.  The need to perform contrast radiography must be weighed against the stress it would place upon the foal.

===Biopsy===

===Biopsy===

 

* Due to '''parasites''' - [[Gasterophilus spp.|''Gasterophilus'' (Bots)]].

* Due to '''parasites''' - [[Gasterophilus spp.|''Gasterophilus'' (Bots)]].

* Bots are not as common as they once were.

* Bots are not as common as they once were.

* The parasites are believed to be non-pathogenic, but in large numbers they probably produce some discomfort and poor growth.

* 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 [[Forestomach - Anatomy & Physiology|stomach]] of the horse as, in other species.

* Carcinoma can also produce ulceration in the [[Forestomach - Anatomy & Physiology|stomach]] of the horse as, in other species.