Changes

==Aetiology==

==Aetiology==

The specific cause of the impaction is not always apparent<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> but the obstruction typically consists of excessive dry, coarse ingesta such as straw bedding or poor quality forage.<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>  It may also be composed of foreign bodies, ingested materials that form a mass (such as persimmon seeds or mesquite beans<ref>Kellam, L.L, Johnson, P.J, Kramer, J, Keegan, K.G (2000) Gastric impaction and obstruction of the small intestine associated with persimmon phytobezoar in a horse.  ''J Am Vet Med Assoc'', 216:1279-1281.  In: Blikslager, A.T (2005) Treatment of Gastrointestinal Obstruction - Stomach Impaction, Ileal Impaction and Caecal Impaction, ''American Association of Equine Practitioners (AAEP)'', reproduced at www.ivis.org.</ref><ref>Cummings, C.A, Copedge, K.J, Confer, A.W (1997) Equine gastric impaction, ulceration, and perforation due to persimmon (''Diospyros virginiana'') ingestion.  ''J Vet Diagn Invest'', 9:311-313.  In: Blikslager, A.T (2005) Treatment of Gastrointestinal Obstruction - Stomach Impaction, Ileal Impaction and Caecal Impaction, ''American Association of Equine Practitioners (AAEP)'', reproduced at www.ivis.org.</ref><ref>Honnas, C.M, Schumacher, J (1985) Primary gastric impaction in a pony.  ''J Am Vet Med Assoc'', 187:501-502.  In: Blikslager, A.T (2005) Treatment of Gastrointestinal Obstruction - Stomach Impaction, Ileal Impaction and Caecal Impaction, ''American Association of Equine Practitioners (AAEP)'', reproduced at www.ivis.org.</ref>) or feeds that tend to swell after ingestion.(151-4 in Sanchez) Gastric impaction may be the result of an gastric atony or defective secretion.<ref name="Edwards">Edwards, G.B (2003) 'Gastric Pathology' in Chuit, P, Kuffer, A, Montavon, S (2003) ''Congress on Equine Medicine and Surgery'', International Veterinary Information Service (www.ivis.org), Ithaca, New York, USA.</ref>

The specific cause of the impaction is not always apparent<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> but the obstruction typically consists of excessive dry, coarse ingesta such as straw bedding or poor quality forage.<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>  It may also be composed of foreign bodies, ingested materials that form a mass (such as persimmon seeds or mesquite beans<ref>Kellam, L.L, Johnson, P.J, Kramer, J, Keegan, K.G (2000) Gastric impaction and obstruction of the small intestine associated with persimmon phytobezoar in a horse.  ''J Am Vet Med Assoc'', 216:1279-1281.  In: Blikslager, A.T (2005) Treatment of Gastrointestinal Obstruction - Stomach Impaction, Ileal Impaction and Caecal Impaction, ''American Association of Equine Practitioners (AAEP)'', reproduced at www.ivis.org.</ref><ref>Cummings, C.A, Copedge, K.J, Confer, A.W (1997) Equine gastric impaction, ulceration, and perforation due to persimmon (''Diospyros virginiana'') ingestion.  ''J Vet Diagn Invest'', 9:311-313.  In: Blikslager, A.T (2005) Treatment of Gastrointestinal Obstruction - Stomach Impaction, Ileal Impaction and Caecal Impaction, ''American Association of Equine Practitioners (AAEP)'', reproduced at www.ivis.org.</ref><ref>Honnas, C.M, Schumacher, J (1985) Primary gastric impaction in a pony.  ''J Am Vet Med Assoc'', 187:501-502.  In: Blikslager, A.T (2005) Treatment of Gastrointestinal Obstruction - Stomach Impaction, Ileal Impaction and Caecal Impaction, ''American Association of Equine Practitioners (AAEP)'', reproduced at www.ivis.org.</ref>) or feeds that tend to swell after ingestion.  Gastric impaction may be the result of a gastric atony or defective secretion.<ref name="Edwards">Edwards, G.B (2003) 'Gastric Pathology' in Chuit, P, Kuffer, A, Montavon, S (2003) ''Congress on Equine Medicine and Surgery'', International Veterinary Information Service (www.ivis.org), Ithaca, New York, USA.</ref>

===Predisposing factors===

===Predisposing factors===