Changes

*Western performance horses 40%<ref>Bertone, J (2000) Prevalence of gastric ulcers in elite, heavy use western performance horses.  ''Proc Am Assoc Equine Pract'', 46:256-259.</ref>

*Western performance horses 40%<ref>Bertone, J (2000) Prevalence of gastric ulcers in elite, heavy use western performance horses.  ''Proc Am Assoc Equine Pract'', 46:256-259.</ref>

*Thoroughbred broodmares (67-77%)<ref>Jeune, S.S, Nieto, J.E, Dechant, J.E, Snyder, J.R (2009) Prevalence of gastric ulcers in Thoroughbred broodmares in pasture: a preliminary report.  ''Vet J'', 181(3):251-5.</ref>

*Thoroughbred broodmares (67-77%)<ref>Jeune, S.S, Nieto, J.E, Dechant, J.E, Snyder, J.R (2009) Prevalence of gastric ulcers in Thoroughbred broodmares in pasture: a preliminary report.  ''Vet J'', 181(3):251-5.</ref>

*Nonracing performance horses (17 % precompetition, 56% postcompetition)

*Nonracing performance horses (17% prec-ompetition, 56% post-competition)<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:</ref>

*Pleasure horses in full work ~ 60%<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>   

*Pleasure horses in full work ~ 60%<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>   

*Pleasure, riding lessons, showing 37%<ref>Murray, M.J, Grodinsky, C, Anderson, C.W, Radue, P.F, Schmidt, G.R (1989) Gastric ulcers in horses: a comparison of endoscopic findings in horses with and without clinical signs.  ''Equine Vet J Suppl'', 7:68-72.</ref>

*Pleasure, riding lessons, showing 37%<ref>Murray, M.J, Grodinsky, C, Anderson, C.W, Radue, P.F, Schmidt, G.R (1989) Gastric ulcers in horses: a comparison of endoscopic findings in horses with and without clinical signs.  ''Equine Vet J Suppl'', 7:68-72.</ref>

*Foals – 25-57%<ref>Wilson, J.H (1986) Gastric and duodenal ulcers in foals: a retrospective study.  ''Proc Equine Colic Res Symp 2nd:126-128.</ref><ref>Murray, M.J, Grodinsky, C, Cowles, R.R, ''et al.''(1990) Endoscopic evaluation of changes in gastric lesions of Thoroughbred foals.  ''J Am Vet Med Assoc'', 196:1623-1627.</ref><ref>Murray, M.J (1989) Endoscopic appearance of gastric lesions in foals: 94 cases (1987-1988).  J Am Vet Med Assoc, 195:1135-1141.</ref> unknown, probably common, increasing or diagnosing more? Overall, the currently accepted prevalence estimates is 30-50%, increasing sharply in foals demonstrating signs of disease, especially gastrointestinal signs.<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>

*Foals – 25-57%<ref>Wilson, J.H (1986) Gastric and duodenal ulcers in foals: a retrospective study.  ''Proc Equine Colic Res Symp 2nd:126-128.</ref><ref>Murray, M.J, Grodinsky, C, Cowles, R.R, ''et al.''(1990) Endoscopic evaluation of changes in gastric lesions of Thoroughbred foals.  ''J Am Vet Med Assoc'', 196:1623-1627.</ref><ref>Murray, M.J (1989) Endoscopic appearance of gastric lesions in foals: 94 cases (1987-1988).  J Am Vet Med Assoc, 195:1135-1141.</ref> unknown, probably common, increasing or diagnosing more? Overall, the currently accepted prevalence estimates is 30-50%, increasing sharply in foals demonstrating signs of disease, especially gastrointestinal signs.<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 prevalence and severity of ulcers increases with work intensity<ref name="Merck">Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial</ref> and duration(Murray 1994; Orsini and Pipers 1997 in Orsini),  thus racehorses in active training are more often affected (Hammond et al. 1986; Johnson et al. 1994) and in half of these,  the lesions are moderate to severe.<ref name="Merck">Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial</ref>  In one study, all horses developed gastric ulcers within 2 weeks of entering simulated race training. (Vatistas 2 1999).  Lesions are thought to be chronically progressive during race training, but to regress during retirement.(Hammond 1986). Horses with signs of gastrointestinal distress also demonstrate an increased frequency and severity of ulcerative lesions.(EGUC)Among show horses, 82% of those with signs of abdominal discomfort had gastric ulcers (Murray 1992a).<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>  Around 30% of adult horses and about 50% of foals have mild gastric erosions which heal without treatment or clinical signs.<ref name="Merck">Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial</ref>  In 201 clinically normal horses in Denmark, 53% had EGUS with severity score >2 and older horses were more likely to have lesions in both regions of the stomach (Luthersson, N, Nielsen, K.H, Harris, P, Parkin, T.D (2009) The prevalence and anatomical distribution of equine gastric ulcer syndrome (EGUS) in 201 horses in Denmark.  Equine Vet J, 41(7):619-24.

The prevalence and severity of ulcers increases with work intensity<ref name="Merck">Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial</ref> and duration(Murray 1994; Orsini and Pipers 1997 in Orsini),  thus racehorses in active training are more often affected<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> (Johnson et al. 1994) and in half of these,  the lesions are moderate to severe.<ref name="Merck">Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial</ref>  In one study, all horses developed gastric ulcers within 2 weeks of entering simulated race training.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> Lesions are thought to be chronically progressive during race training, but to regress during retirement.<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>  Horses with signs of gastrointestinal distress also demonstrate an increased frequency and severity of ulcerative lesions.(EGUC)Among show horses, 82% of those with signs of abdominal discomfort had gastric ulcers (Murray 1992a).<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>  Around 30% of adult horses and about 50% of foals have mild gastric erosions which heal without treatment or clinical signs.<ref name="Merck">Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial</ref>  In 201 clinically normal horses in Denmark, 53% had EGUS with severity score >2 and older horses were more likely to have lesions in both regions of the stomach (Luthersson, N, Nielsen, K.H, Harris, P, Parkin, T.D (2009) The prevalence and anatomical distribution of equine gastric ulcer syndrome (EGUS) in 201 horses in Denmark.  Equine Vet J, 41(7):619-24.

==Signalment==

==Signalment==