Changes

==Risk Factors==

==Risk Factors==

===Exercise===

====Exercise====

There appears to be a high prevalence of gastric ulcers in horses performing in most disciplines including racing, endurance, show jumping, dressage and western performance.<ref>Hartmann, A.M, Frankeny, R.L (2003) A preliminary investigation into the association between competition and gastric ulcer formation in non-racing performance horses.  ''J Equine Vet Sci'', 23:560-561.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref>  Although this may be related to exercise, other confounding factors associated with these disciplines such as travel, diet, feeding regime, NSAIDs and stress may be significant.  However, Vatistas and co-workers (1999) were able to induce and maintain EGUS in racehorses in fast work without the use of NSAIDs or fasting before exercise.<ref name="Vatistas 2">Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>  There is also evidence that training for just 8 days is suffcient to induce gastric ulcers.<ref>White, G, McClure, S.R, Siifferman, R, Holste, J.E, Fleishman, C, Murray, M.J, Cramer, L.G (2007) Effects of short-term light to heavy exercise on gastric ulcer development in horses and efficacy of omeprazole paste in preventing gastric ulceration.  ''J Am Vet Med Assoc'', 230(11):1680-2.</ref>  Furthermore, the higher prevalence of gastric ulcers at post mortem in racehorses in training compared to those in retirement adds weight to the hypothesis that exercise is an important risk factor for EGUS.<ref name="Hammond">Hammond, C.J, Mason, D.K, Watkins, K.L (1986) Gastric ulceration in mature Thoroughbred horses.  ''Equine Vet J'', 18(4):284-287.</ref>  Strenuous exercise is known to stimulate gastrin release which has effects on HCl secretion, gastric emptying and gastric blood flow.  It is also thought that exposure of the squamous mucosa to acid is increased as the stomach is compressed by the abdominal viscera and diaphragm during excercise.<ref>Lorenzo-Figueras, M, Merritt, A.M (2002) Effects of exercise on gastric volume and pH in the proximal portion of the stomach of horses.  ''Am J Vet Res'', 63:1481-1487.</ref>

There appears to be a high prevalence of gastric ulcers in horses performing in most disciplines including racing, endurance, show jumping, dressage and western performance.<ref>Hartmann, A.M, Frankeny, R.L (2003) A preliminary investigation into the association between competition and gastric ulcer formation in non-racing performance horses.  ''J Equine Vet Sci'', 23:560-561.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref>  Although this may be related to exercise, other confounding factors associated with these disciplines such as travel, diet, feeding regime, NSAIDs and stress may be significant.  However, Vatistas and co-workers (1999) were able to induce and maintain EGUS in racehorses in fast work without the use of NSAIDs or fasting before exercise.<ref name="Vatistas 2">Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>  There is also evidence that training for just 8 days is suffcient to induce gastric ulcers.<ref>White, G, McClure, S.R, Siifferman, R, Holste, J.E, Fleishman, C, Murray, M.J, Cramer, L.G (2007) Effects of short-term light to heavy exercise on gastric ulcer development in horses and efficacy of omeprazole paste in preventing gastric ulceration.  ''J Am Vet Med Assoc'', 230(11):1680-2.</ref>  Furthermore, the higher prevalence of gastric ulcers at post mortem in racehorses in training compared to those in retirement adds weight to the hypothesis that exercise is an important risk factor for EGUS.<ref name="Hammond">Hammond, C.J, Mason, D.K, Watkins, K.L (1986) Gastric ulceration in mature Thoroughbred horses.  ''Equine Vet J'', 18(4):284-287.</ref>  Strenuous exercise is known to stimulate gastrin release which has effects on HCl secretion, gastric emptying and gastric blood flow.  It is also thought that exposure of the squamous mucosa to acid is increased as the stomach is compressed by the abdominal viscera and diaphragm during excercise.<ref>Lorenzo-Figueras, M, Merritt, A.M (2002) Effects of exercise on gastric volume and pH in the proximal portion of the stomach of horses.  ''Am J Vet Res'', 63:1481-1487.</ref>

===Housing and Transport===

====Housing and Transport====

Housing in '''stables''' has been proposed as a risk factor for gastric ulcers, with more lesions being found in confined horses compared to those out at grass.<ref>Murray, M.J, Eichorn, E.S (1996) Effects of intermittent feed deprivation, intermittent feed deprivation with ranitidine administration, and stall

Housing in '''stables''' has been proposed as a risk factor for gastric ulcers, with more lesions being found in confined horses compared to those out at grass.<ref>Murray, M.J, Eichorn, E.S (1996) Effects of intermittent feed deprivation, intermittent feed deprivation with ranitidine administration, and stall

confinement with ''ad libitum'' access to hay on gastric ulceration in horses.  ''Am J Vet Res'', 57:1599-1603.</ref>  However, when comparing solitary stable confinement with stabling next to a companion, and finally turn out in a paddock, Husted and colleagues (2008) found that the environmental situation had no effect on mucosal acid exposure in the equine stomach.<ref>Husted, L, Sanchex, L.C, Olsen, S.N, Baptiste, K.E, Merritt, A.M (2008) Effect of paddock vs. stall housing on 24 hour gastric pH within the proximal and ventral equine stomach.  ''Equine Vet J'', 40(4):337-41.</ref>  '''Transport''' has also been shown to induce squamous mucosal ulceration in horses.<ref>McClure, S.R, Carithers, D.S, Gross, S.J, Murray, M.J (2005) Gastric ulcer development in horses in a simulated show or training environment.  ''J Am Vet Med Assoc'', 227:775-777.</ref>

confinement with ''ad libitum'' access to hay on gastric ulceration in horses.  ''Am J Vet Res'', 57:1599-1603.</ref>  However, when comparing solitary stable confinement with stabling next to a companion, and finally turn out in a paddock, Husted and colleagues (2008) found that the environmental situation had no effect on mucosal acid exposure in the equine stomach.<ref>Husted, L, Sanchex, L.C, Olsen, S.N, Baptiste, K.E, Merritt, A.M (2008) Effect of paddock vs. stall housing on 24 hour gastric pH within the proximal and ventral equine stomach.  ''Equine Vet J'', 40(4):337-41.</ref>  '''Transport''' has also been shown to induce squamous mucosal ulceration in horses.<ref>McClure, S.R, Carithers, D.S, Gross, S.J, Murray, M.J (2005) Gastric ulcer development in horses in a simulated show or training environment.  ''J Am Vet Med Assoc'', 227:775-777.</ref>

===Diet===

====Diet====

'''Feed deprivation''' encourages gastric ulceration in two ways: (1) it precludes the buffering capacity of protein leading to a reduced gastric pH<ref>Murray, M.J, Schusser, G.F (1993) Measurement of 24-h gastric pH using an indwelling pH electrode in horses unfed, fed and treated with ranitidine.  ''Equine Vet J'', 25:417-421.  In: Sandin, A, Skidell, J, Haggstrom, J, Nilsson, G (2000) ''Postmortem'' findings of gastric ulcers in Swedish horses older than age one year: a retrospective study of 3715 horses (1924–1996).  ''Equine Vet J'', 32(1):36-42.</ref> and (2) it empties the stomach and exposes the squamous mucosa to the more mobile gastric juice.<ref name="Sandin">Sandin, A, Skidell, J, Haggstrom, J, Nilsson, G (2000) ''Postmortem'' findings of gastric ulcers in Swedish horses older than age one year: a retrospective study of 3715 horses (1924–1996).  ''Equine Vet J'', 32(1):36-42.</ref>  It is unsurprising, therefore, that an alternating feed-fast protocol would produce a consistent model of ulcer induction in the equine squamous mucosa.<ref>Murray, M.J, Schusser, G.F (1993) Measurement of 24-h gastric pH using an indwelling pH electrode in horses unfed, fed and treated with ranitidine.  ''Equine Vet J'', 25:417-421.  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><ref>Murray, M.J (1994) Equine model of inducing ulceration in alimentary squamous epithelial mucosa.  ''Dig Dis Sci'', 39:2530-2535.  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>  Despite this, feed deprivation is not a prerequisite for gastric ulceration in the horse.<ref name="Vatistas thesis">Vatistas, N.J (1998) Gastric Ulceration in the Racing Thoroughbred.  ''PhD Thesis''.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>  Diets that are plentiful in roughage prolong the mastication process and the production of salivary bicarbonate that protects the gastric mucosa.  A diet of '''high grain and low roughage''' thus predisposes to EGUS.<ref name="Nadeau"> In: 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 sort of diet is commonly fed to racehorses but dietary components have also been shown to influence EGUS risk in nonracehorses.<ref>Luthersson, N, Nielson, K.H, Harris, P, Parkin, T.D (2009) Risk factors associated with equine gastric ulceration syndrome (EGUS) in 201 horses in Denmark.  ''Equine Vet J'', 41(7):625-30.</ref>  Ponies fed a '''concentrate diet''' had a greater prevalence of gastric ulcers than ponies fed hay alone.<ref name="Vatistas 2">Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref> and this may be because grain and pelleted feeds are asssociated with increased serum gastrin.<ref>Smyth, G.B, Young, D.W, Hammond, L.S (1988) Effects of diet and feeding on post-prandial serum gastrin and insulin concentrations in adult horses.  ''Equine Vet J Suppl'' 7:56-59.</ref>  '''High starch meals''' are also a risk because they are fermented to volatile fatty acids (VFAs) and lactic acid and are emptied from the stomach relatively slowly.<ref>Mètayer, N, Lhôte, M, Bahr, A, Cohen, N.D, Kim, I, Rousell, A.J, Julliand, V (2004) Meal size and starch content affect gastric emptying in horses.  ''Equine Vet J'', 36:434-440.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref><ref>Taharaguchi, S, Okai, K, Orita, Y, Kuwano, M, Ueno, T, Taniyama, H (2004) Relation between amounts of concentrated feed given mares and gastric ulcers in foals.  ''J Japan Vet Med Ass'', 57:366-370.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref><ref>Boswinkel, A.M, Ellis, A.D, Sloet van Oldruitenborgh-Oosterbaan, M.M (2007) The influence of low versus high fibre haylage diets in combination with training or pasture rest on equine gastric ulceration syndrome (EGUS).  ''Pferdeheilkunde'', 23:123-130.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref>

'''Feed deprivation''' encourages gastric ulceration in two ways: (1) it precludes the buffering capacity of protein leading to a reduced gastric pH<ref>Murray, M.J, Schusser, G.F (1993) Measurement of 24-h gastric pH using an indwelling pH electrode in horses unfed, fed and treated with ranitidine.  ''Equine Vet J'', 25:417-421.  In: Sandin, A, Skidell, J, Haggstrom, J, Nilsson, G (2000) ''Postmortem'' findings of gastric ulcers in Swedish horses older than age one year: a retrospective study of 3715 horses (1924–1996).  ''Equine Vet J'', 32(1):36-42.</ref> and (2) it empties the stomach and exposes the squamous mucosa to the more mobile gastric juice.<ref name="Sandin">Sandin, A, Skidell, J, Haggstrom, J, Nilsson, G (2000) ''Postmortem'' findings of gastric ulcers in Swedish horses older than age one year: a retrospective study of 3715 horses (1924–1996).  ''Equine Vet J'', 32(1):36-42.</ref>  It is unsurprising, therefore, that an alternating feed-fast protocol would produce a consistent model of ulcer induction in the equine squamous mucosa.<ref>Murray, M.J, Schusser, G.F (1993) Measurement of 24-h gastric pH using an indwelling pH electrode in horses unfed, fed and treated with ranitidine.  ''Equine Vet J'', 25:417-421.  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><ref>Murray, M.J (1994) Equine model of inducing ulceration in alimentary squamous epithelial mucosa.  ''Dig Dis Sci'', 39:2530-2535.  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>  Despite this, feed deprivation is not a prerequisite for gastric ulceration in the horse.<ref name="Vatistas thesis">Vatistas, N.J (1998) Gastric Ulceration in the Racing Thoroughbred.  ''PhD Thesis''.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>  Diets that are plentiful in roughage prolong the mastication process and the production of salivary bicarbonate that protects the gastric mucosa.  A diet of '''high grain and low roughage''' thus predisposes to EGUS.<ref name="Nadeau"> In: 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 sort of diet is commonly fed to racehorses but dietary components have also been shown to influence EGUS risk in nonracehorses.<ref>Luthersson, N, Nielson, K.H, Harris, P, Parkin, T.D (2009) Risk factors associated with equine gastric ulceration syndrome (EGUS) in 201 horses in Denmark.  ''Equine Vet J'', 41(7):625-30.</ref>  Ponies fed a '''concentrate diet''' had a greater prevalence of gastric ulcers than ponies fed hay alone.<ref name="Vatistas 2">Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref> and this may be because grain and pelleted feeds are asssociated with increased serum gastrin.<ref>Smyth, G.B, Young, D.W, Hammond, L.S (1988) Effects of diet and feeding on post-prandial serum gastrin and insulin concentrations in adult horses.  ''Equine Vet J Suppl'' 7:56-59.</ref>  '''High starch meals''' are also a risk because they are fermented to volatile fatty acids (VFAs) and lactic acid and are emptied from the stomach relatively slowly.<ref>Mètayer, N, Lhôte, M, Bahr, A, Cohen, N.D, Kim, I, Rousell, A.J, Julliand, V (2004) Meal size and starch content affect gastric emptying in horses.  ''Equine Vet J'', 36:434-440.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref><ref>Taharaguchi, S, Okai, K, Orita, Y, Kuwano, M, Ueno, T, Taniyama, H (2004) Relation between amounts of concentrated feed given mares and gastric ulcers in foals.  ''J Japan Vet Med Ass'', 57:366-370.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref><ref>Boswinkel, A.M, Ellis, A.D, Sloet van Oldruitenborgh-Oosterbaan, M.M (2007) The influence of low versus high fibre haylage diets in combination with training or pasture rest on equine gastric ulceration syndrome (EGUS).  ''Pferdeheilkunde'', 23:123-130.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref>

===Other ailments===

====Other ailments====

    

    

Conditions that produce abdominal pain and/or inappetance are likely to reduce food intake and predipose to gastric ulcers.<ref name="Sandin">Sandin, A, Skidell, J, Haggstrom, J, Nilsson, G (2000) ''Postmortem'' findings of gastric ulcers in Swedish horses older than age one year: a retrospective study of 3715 horses (1924–1996).  ''Equine Vet J'', 32(1):36-42.</ref>  This may be the reason that '''colic''' and other gastrointestinal disorders have been associated with EGUS.<ref>Furr, M.O, Murray, M.J (1989) Treatment of gastric ulcers in horses with histamine type 2 receptor antagonists.  ''Equine Vet J Suppl'', 7:77-79.</ref>  Alternatively, EGUS may be part of a more general gastrointestinal disease complex.<ref name="Vatistas 2">Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>  '''Stress''' induced by other clinical disorders has been reported to increase the prevalence of EGUS in neonatal foals<ref name="Furr">Furr, M.O, Murray, M.J, Ferguson, D.C (1992) The effects of stress on gastric ulceration, T3, T4, reverse T3 and cortisol in neonatal foals.  ''Equine Vet J'', 24:37-40.</ref> and a similar mechanism may exist for adult animals.<ref name="Vatistas 2">Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>

Conditions that produce abdominal pain and/or inappetance are likely to reduce food intake and predipose to gastric ulcers.<ref name="Sandin">Sandin, A, Skidell, J, Haggstrom, J, Nilsson, G (2000) ''Postmortem'' findings of gastric ulcers in Swedish horses older than age one year: a retrospective study of 3715 horses (1924–1996).  ''Equine Vet J'', 32(1):36-42.</ref>  This may be the reason that '''colic''' and other gastrointestinal disorders have been associated with EGUS.<ref>Furr, M.O, Murray, M.J (1989) Treatment of gastric ulcers in horses with histamine type 2 receptor antagonists.  ''Equine Vet J Suppl'', 7:77-79.</ref>  Alternatively, EGUS may be part of a more general gastrointestinal disease complex.<ref name="Vatistas 2">Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>  '''Stress''' induced by other clinical disorders has been reported to increase the prevalence of EGUS in neonatal foals<ref name="Furr">Furr, M.O, Murray, M.J, Ferguson, D.C (1992) The effects of stress on gastric ulceration, T3, T4, reverse T3 and cortisol in neonatal foals.  ''Equine Vet J'', 24:37-40.</ref> and a similar mechanism may exist for adult animals.<ref name="Vatistas 2">Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>

===NSAIDs===

====NSAIDs====

As in [[Gastric Ulceration - all species|other species]], nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to cause gastric ulcers in horses. Typicaly this is associated with high doses or frequent administration of phenylbutazone or flunixin meglumine.  However, although there is evidence to the contrary,<ref>Andrews, F.M, Reinemeyer, C.R, Longhofer, S.L (2009) Effects of top-dress formulations of suxibuzone and phenylbutazone on development of gastric ulcers in horses. ''Vet Ther'', 10(3):113-20.</ref>therapeutic doses of NSAIDs may be sufficient to induce EGUS.  Other studies have suggested that suxibuzone causes significantly less ulcerogenic effects than phenylbutazone when administered orally<ref>Monreal, L, Sabatè, D, Segura, D, Mayós, I, Homedes, J (2004) Lower gastric ulcerogenic effect of suxibuzone compared to phenylbutazone when administered orally to horses.  ''Res Vet Sci'', 76:145-149.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref>and that combination treatment with phenylbutazone and flunixin meglumine may be more risky than phenylbutazone alone.<ref>Reed, S.K, Messer, N.T, Tessman, R.K, Keegan, K.G (2006) Effects of phenylbutazone alone or in combination with flunixin meglumine on blood protein concentrations in horses.  ''Am J Vet Res'', 67:398-402.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref> The ulcers produced by NSAIDs are unusual in that they have a predilection for the glandular mucosa<ref>MacAllister, C.G, Morgan, S.J, Borne, A.T, Pollet, R.A, (1993) Comparison of adverse effects of phenylbutazone, flunixin meglumine, and ketoprofen in horses.  ''J Am Vet Med Ass'', 202:71-77.  In: Jonsson, H, Egenvall, A (2006) Prevalence of gastric ulceration in Swedish Standardbreds in race training.  ''Equine Vet J'', 38(3):209-213.</ref><ref>Furr, M.O, Murray, M.J (1989) Treatment of gastric ulcers in horses with histamine type 2 receptor antagonists.  ''Equine Vet J Suppl'', 7:77-79.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref><ref>Kumaran, D, Bhuvanakumar, C.K (1994) Gastro duodenal ulceration in foals - a discussion.  ''Cenfaur Mylapore'', 10:83-86. In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>, they may look different endoscopically from ulcers that occur naturally,<ref name="Jonsson">Jonsson, H, Egenvall, A (2006) Prevalence of gastric ulceration in Swedish Standardbreds in race training.  ''Equine Vet J'', 38(3):209-213.</ref> and they appear to heal spontaneously.<ref>Jones, W.E (1983) Gastrointestinal ulcers [foal].  ''Equine Vet Data'', 4:305-308.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref><ref>MacAllister, C.G, Sangiah, S (1993) Effect of ranitidine (in healing of experimentally induced gastric ulcers in ponies.  ''Am J Vet Res'', 54:1103-1107.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref> Despite the well-established link bewteen NSAIDs and ulcers, NSAIDs are rarely responsible for the lesions in horses in race training.<ref>Vatistas N.J, Snyder, J.R, Carlson, G.P, Johnson, B, Arther, R.M, Thurmiind, M, Lloyd, K.C.K (1994) Epidemiology study of gastric ulcerarion in the Thoroughbred race horse: 202 horses.  ''Proc Am Ass Equine Pract'', 39:125-126.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref><ref>Murray, M.J, Schusser, G.F, Pipers, F.S, Gro:ss, S.J (1996) Factors associated with gastric lesions in Thoroughbred racehorses.  ''Equine Vet J'', 28:368-374.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref><ref name="Vatistas thesis">Vatistas, N.J (1998) Gastric Ulceration in the Racing Thoroughbred.  ''PhD Thesis''.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>

As in [[Gastric Ulceration - all species|other species]], nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to cause gastric ulcers in horses. Typicaly this is associated with high doses or frequent administration of phenylbutazone or flunixin meglumine.  However, although there is evidence to the contrary,<ref>Andrews, F.M, Reinemeyer, C.R, Longhofer, S.L (2009) Effects of top-dress formulations of suxibuzone and phenylbutazone on development of gastric ulcers in horses. ''Vet Ther'', 10(3):113-20.</ref>therapeutic doses of NSAIDs may be sufficient to induce EGUS.  Other studies have suggested that suxibuzone causes significantly less ulcerogenic effects than phenylbutazone when administered orally<ref>Monreal, L, Sabatè, D, Segura, D, Mayós, I, Homedes, J (2004) Lower gastric ulcerogenic effect of suxibuzone compared to phenylbutazone when administered orally to horses.  ''Res Vet Sci'', 76:145-149.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref>and that combination treatment with phenylbutazone and flunixin meglumine may be more risky than phenylbutazone alone.<ref>Reed, S.K, Messer, N.T, Tessman, R.K, Keegan, K.G (2006) Effects of phenylbutazone alone or in combination with flunixin meglumine on blood protein concentrations in horses.  ''Am J Vet Res'', 67:398-402.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref> The ulcers produced by NSAIDs are unusual in that they have a predilection for the glandular mucosa<ref>MacAllister, C.G, Morgan, S.J, Borne, A.T, Pollet, R.A, (1993) Comparison of adverse effects of phenylbutazone, flunixin meglumine, and ketoprofen in horses.  ''J Am Vet Med Ass'', 202:71-77.  In: Jonsson, H, Egenvall, A (2006) Prevalence of gastric ulceration in Swedish Standardbreds in race training.  ''Equine Vet J'', 38(3):209-213.</ref><ref>Furr, M.O, Murray, M.J (1989) Treatment of gastric ulcers in horses with histamine type 2 receptor antagonists.  ''Equine Vet J Suppl'', 7:77-79.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref><ref>Kumaran, D, Bhuvanakumar, C.K (1994) Gastro duodenal ulceration in foals - a discussion.  ''Cenfaur Mylapore'', 10:83-86. In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>, they may look different endoscopically from ulcers that occur naturally,<ref name="Jonsson">Jonsson, H, Egenvall, A (2006) Prevalence of gastric ulceration in Swedish Standardbreds in race training.  ''Equine Vet J'', 38(3):209-213.</ref> and they appear to heal spontaneously.<ref>Jones, W.E (1983) Gastrointestinal ulcers [foal].  ''Equine Vet Data'', 4:305-308.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref><ref>MacAllister, C.G, Sangiah, S (1993) Effect of ranitidine (in healing of experimentally induced gastric ulcers in ponies.  ''Am J Vet Res'', 54:1103-1107.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref> Despite the well-established link bewteen NSAIDs and ulcers, NSAIDs are rarely responsible for the lesions in horses in race training.<ref>Vatistas N.J, Snyder, J.R, Carlson, G.P, Johnson, B, Arther, R.M, Thurmiind, M, Lloyd, K.C.K (1994) Epidemiology study of gastric ulcerarion in the Thoroughbred race horse: 202 horses.  ''Proc Am Ass Equine Pract'', 39:125-126.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref><ref>Murray, M.J, Schusser, G.F, Pipers, F.S, Gro:ss, S.J (1996) Factors associated with gastric lesions in Thoroughbred racehorses.  ''Equine Vet J'', 28:368-374.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref><ref name="Vatistas thesis">Vatistas, N.J (1998) Gastric Ulceration in the Racing Thoroughbred.  ''PhD Thesis''.  In: Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref>

===Temperament===

====Temperament====

A nervous disposition has been linked with gastric ulcers<ref>McClure, S.R, Glickman, L.T, Glickman, N.W (1999) Prevalence of gastric ulcers in show horses.  ''J Am Vet Med Ass 215:1130-1133.  In: In: Jonsson, H, Egenvall, A (2006) Prevalence of gastric ulceration in Swedish Standardbreds in race training.  ''Equine Vet J'', 38(3):209-213.</ref>but the same association was not seen in another study.<ref>Vatistas, N.J, Snyder, J.R, Carlson, G, Johnson, B, Arthur, R.M, Thurmond, M, Zhou, H, Lloyd, L.K (1999) Cross-sectional study of gastric ulcers of the squamous mucosa in Thoroughbred racehorses.  ''Equine Vet J Suppl'', 29:34-39.  In: Jonsson, H, Egenvall, A (2006) Prevalence of gastric ulceration in Swedish Standardbreds in race training.  ''Equine Vet J'', 38(3):209-213.</ref>  The physiological and psychological stresses of training, housing, boredom, travel, mixing, hospitalisation and entering new environments<ref name="Vatistas 2">Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref> may increase the risk of developing EGUS.  In foals hypoxia may also be a risk factor.

A nervous disposition has been linked with gastric ulcers<ref>McClure, S.R, Glickman, L.T, Glickman, N.W (1999) Prevalence of gastric ulcers in show horses.  ''J Am Vet Med Ass 215:1130-1133.  In: In: Jonsson, H, Egenvall, A (2006) Prevalence of gastric ulceration in Swedish Standardbreds in race training.  ''Equine Vet J'', 38(3):209-213.</ref>but the same association was not seen in another study.<ref>Vatistas, N.J, Snyder, J.R, Carlson, G, Johnson, B, Arthur, R.M, Thurmond, M, Zhou, H, Lloyd, L.K (1999) Cross-sectional study of gastric ulcers of the squamous mucosa in Thoroughbred racehorses.  ''Equine Vet J Suppl'', 29:34-39.  In: Jonsson, H, Egenvall, A (2006) Prevalence of gastric ulceration in Swedish Standardbreds in race training.  ''Equine Vet J'', 38(3):209-213.</ref>  The physiological and psychological stresses of training, housing, boredom, travel, mixing, hospitalisation and entering new environments<ref name="Vatistas 2">Vatistas, N.J, Sifferman, R.L, Holste, J, Cox, J.L, Pinalto, G, Schultz, K.T (1999) Induction and maintenance of gastric ulceration in horses in simulated race training.  ''Equine Vet J Suppl'', 29:40-44</ref> may increase the risk of developing EGUS.  In foals hypoxia may also be a risk factor.

''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.''

''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<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>

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>

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,<ref>MacAllister, C.G, Andrews F.M, Deegan E, Ruoff, W, Olovson, S.G (1997) A scoring system for gastric ulcers in horses.  ''Equine Vet J'', 29:430-433.</ref> 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.<ref>Andrews, F.M, Reinmeyers, C.R, McCracken, M.D, Blackford, J.T, Nadeau, J.A, Saabye, L, Sotell, M, Saxton, A (2002) Comparison of endoscopic, necropsy and histology scoring of equine gastric ulcers.  ''Equine Vet J'',34(5):475-478.</ref>  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.

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,<ref>MacAllister, C.G, Andrews F.M, Deegan E, Ruoff, W, Olovson, S.G (1997) A scoring system for gastric ulcers in horses.  ''Equine Vet J'', 29:430-433.</ref> 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.<ref>Andrews, F.M, Reinmeyers, C.R, McCracken, M.D, Blackford, J.T, Nadeau, J.A, Saabye, L, Sotell, M, Saxton, A (2002) Comparison of endoscopic, necropsy and histology scoring of equine gastric ulcers.  ''Equine Vet J'',34(5):475-478.</ref>  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.<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.

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====

A transendoscopic gastric biopsy technique was recently validated for obtaining samples from the gastric glandular mucosa in the live horse.<ref>Rodrigues, N.L, Dore, M, Doucet, M.Y (2009) Validation of a transendoscopic glandular and nonglandular gastric biopsy technique in horses.  ''Equine Vet J'', 41(7):631-5.</ref>Unfortunately this technique failed to produce samples of squamous mucosa that would be suitable for histopathological analysis.  

A transendoscopic gastric biopsy technique was recently validated for obtaining samples from the gastric glandular mucosa in the live horse.<ref>Rodrigues, N.L, Dore, M, Doucet, M.Y (2009) Validation of a transendoscopic glandular and nonglandular gastric biopsy technique in horses.  ''Equine Vet J'', 41(7):631-5.</ref>Unfortunately this technique failed to produce samples of squamous mucosa that would be suitable for histopathological analysis.  

===Laboratory tests===

====Laboratory tests====

Currently, useful and reliable markers for EGUS are lacking.<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>  The SUCCEED® Equine Fecal Blood Test™ uses specific equine monoclonal antibodies to albumin and haemoglobin to detect occult blood in faeces.<ref>Carter, S, Pellegrini, F.A (2006) The use of novel antibody tools to detect the presence of blood in equine feces.  ''Company Bulletin Freedom Health LLC'' 1-3.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref><ref>Pellegrini, F.L, Carter, S.D (2007) An equine necroscopic study to determine the

Currently, useful and reliable markers for EGUS are lacking.<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>  The SUCCEED® Equine Fecal Blood Test™ uses specific equine monoclonal antibodies to albumin and haemoglobin to detect occult blood in faeces.<ref>Carter, S, Pellegrini, F.A (2006) The use of novel antibody tools to detect the presence of blood in equine feces.  ''Company Bulletin Freedom Health LLC'' 1-3.  In: Nadeau, J.A, Andrews, F.M (2009) ''Science: Overviews'' Equine gastric ulcer syndrome: The continuing conundrum.  ''Equine Vet J'', 41(7):611-615.</ref><ref>Pellegrini, F.L, Carter, S.D (2007) An equine necroscopic study to determine the

*Serum alpha1-antitrypsin may be released from damaged gastric tissue<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> and has been detected more frequently in foals with gastric ulceration<ref>Taharaguchi, S, Nagano, A, Okai, K, ''et al.'' (2007) Detection of an isoform of alpha(1)-antitrypsin in serum samples from foals with gastric ulcers.  ''Vet Rec'', 161:338-342.  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>

*Serum alpha1-antitrypsin may be released from damaged gastric tissue<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> and has been detected more frequently in foals with gastric ulceration<ref>Taharaguchi, S, Nagano, A, Okai, K, ''et al.'' (2007) Detection of an isoform of alpha(1)-antitrypsin in serum samples from foals with gastric ulcers.  ''Vet Rec'', 161:338-342.  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>

===Pathology===

====Pathology====

Martineau and co-workers (2009) demonstrated that in a mixed population of horses, a wide range of lesions associated with EGUS could be found at post-mortem.<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):638-44.</ref>  These included hyperkeratosis, punctate scars, diffuse erosions or ulcerations and ''margo injuria'' in the squamous region and hyperaemia, focal erosions and ulcerations in the glandular region.  A novel finding was glandular metaplasia which may be evidence of a protective mechanism developing in response to acid exposure.<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):638-44.</ref>  The authors then devised a pathological scoring system - the '''Equine Gastritis Grading (EGG) system''' - which uses 5 samples of gastric mucosa taken from specific regions of the equine stomach.  For each of these, the inflammatory infiltrate is graded by type, density and location, reactive changes are classified in both squamous and glandular samples and the presence or absence of infectious agents and lymphoid follicles is noted.<ref>Martineau, H, Thompson, H, Taylor, D (2009) Pathology of gastritis and gastric ulceration in the horse. Part 2: a scoring system.  ''Equine Vet J'',41(7):646-51.</ref>  From their findings, a pathogenesis for the development of lesions in the squamous region was proposed:

Martineau and co-workers (2009) demonstrated that in a mixed population of horses, a wide range of lesions associated with EGUS could be found at post-mortem.<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):638-44.</ref>  These included hyperkeratosis, punctate scars, diffuse erosions or ulcerations and ''margo injuria'' in the squamous region and hyperaemia, focal erosions and ulcerations in the glandular region.  A novel finding was glandular metaplasia which may be evidence of a protective mechanism developing in response to acid exposure.<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):638-44.</ref>  The authors then devised a pathological scoring system - the '''Equine Gastritis Grading (EGG) system''' - which uses 5 samples of gastric mucosa taken from specific regions of the equine stomach.  For each of these, the inflammatory infiltrate is graded by type, density and location, reactive changes are classified in both squamous and glandular samples and the presence or absence of infectious agents and lymphoid follicles is noted.<ref>Martineau, H, Thompson, H, Taylor, D (2009) Pathology of gastritis and gastric ulceration in the horse. Part 2: a scoring system.  ''Equine Vet J'',41(7):646-51.</ref>  From their findings, a pathogenesis for the development of lesions in the squamous region was proposed:

==Prevention==

==Prevention==

===Management===

====Management====

*'''Diet:''' ideally turnout to good quality grass.(Murray 1994)  Stabled horses should have continuous access to hay and should be offered this before calorifc needs are met by concentrates.(Orsini)  Alfalfa, or another high calcium or high protein forage may be preventative by increasing gastric pH.(Nadeau et al. 2000; Lybbert et al. 2007; Ralston 2007)  Concentrates should be fed at no more than 0.5kg per 100kg body weight and not more frequently than every 6 hours.(Andrews 2006)  Horses prone to, or at risk of, EGUS should be fed the minimum amount of concentrates necessary.(Nadeau 2009)  

*'''Diet:''' ideally turnout to good quality grass.(Murray 1994)  Stabled horses should have continuous access to hay and should be offered this before calorifc needs are met by concentrates.(Orsini)  Alfalfa, or another high calcium or high protein forage may be preventative by increasing gastric pH.(Nadeau et al. 2000; Lybbert et al. 2007; Ralston 2007)  Concentrates should be fed at no more than 0.5kg per 100kg body weight and not more frequently than every 6 hours.(Andrews 2006)  Horses prone to, or at risk of, EGUS should be fed the minimum amount of concentrates necessary.(Nadeau 2009)  

Most of these suggestions would be difficult if not impossible to achieve for horses in race training, thus prophylactic medication should be considered.(Orsini)

Most of these suggestions would be difficult if not impossible to achieve for horses in race training, thus prophylactic medication should be considered.(Orsini)

===Prophylaxis===

====Prophylaxis====

Omeprazole paste at a lower dose (1-2mg/kg) daily for 3-4 weeks.(100, 107-109 in Sanchez)

Omeprazole paste at a lower dose (1-2mg/kg) daily for 3-4 weeks.(100, 107-109 in Sanchez)

*Prevented ulcers in horses maintained under ulcerogenic conditions (White et al. 2003; McClure et al. 2005a,b,c;White et al. 2007).

*Prevented ulcers in horses maintained under ulcerogenic conditions (White et al. 2003; McClure et al. 2005a,b,c;White et al. 2007).