Changes

*Gastric impaction is suspected if a [[Colic Diagnosis - Naso-gastric Intubation|'''nasogastric tube''']] cannot be passed or if poorly macerated or digested feed material is recovered from the tube when the horse has been starved for several hours.  With gastric distension, the gastoroesophageal junction can become distorted making it difficult to pass the tube.<ref name="Mair">Mair, T.S, Divers, T.J, Ducharme, N.G (2002) '''Manual of Equine Gastroenterology''', ''WB Saunders''.</ref>

*Gastric impaction is suspected if a [[Colic Diagnosis - Naso-gastric Intubation|'''nasogastric tube''']] cannot be passed or if poorly macerated or digested feed material is recovered from the tube when the horse has been starved for several hours.  With gastric distension, the gastoroesophageal junction can become distorted making it difficult to pass the tube.<ref name="Mair">Mair, T.S, Divers, T.J, Ducharme, N.G (2002) '''Manual of Equine Gastroenterology''', ''WB Saunders''.</ref>

*On [[Colic Diagnosis - Rectal Examination|'''rectal examination''']], the spleen may be displaced caudally and medially (but this is not specific for gastric impaction).<ref name="Mair">Mair, T.S, Divers, T.J, Ducharme, N.G (2002) '''Manual of Equine Gastroenterology''', ''WB Saunders''.</ref>

*On [[Colic Diagnosis - Rectal Examination|'''rectal examination''']], the spleen may be displaced caudally and medially (but this is not specific for gastric impaction).<ref name="Mair">Mair, T.S, Divers, T.J, Ducharme, N.G (2002) '''Manual of Equine Gastroenterology''', ''WB Saunders''.</ref>

*'''Endoscopy''' would be indicated in a chronic case(Mair, Blisk) and may show a full stomach after a fast of 18-24hrs.<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 it is not diagnostic for impaction as it is difficult to assess gastric distension by endoscopy.<ref name="Mair">Mair, T.S, Divers, T.J, Ducharme, N.G (2002) '''Manual of Equine Gastroenterology''', ''WB Saunders''.</ref>

*'''Endoscopy''' would be indicated in a chronic case<ref name="Bliks">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> and may show a full stomach after a fast of 18-24hrs.<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 it is not diagnostic for impaction as it is difficult to assess gastric distension by endoscopy.<ref name="Mair">Mair, T.S, Divers, T.J, Ducharme, N.G (2002) '''Manual of Equine Gastroenterology''', ''WB Saunders''.</ref>

*In a small horse or pony, a lateral '''radiograph''' of the cranial abdomen may show the diaphragm displaced cranially

*In a small horse or pony, a lateral '''radiograph''' of the cranial abdomen may show the diaphragm displaced cranially

*[[Colic Diagnosis - Abdominal Ultrasound|'''Ultrasonography''']] may reveal a markedly enlarged gastric echo extending over six or more intercostal spaces on the left side of the abdomen.  A marked increase in the thickness of the wall of the stomach may also be imaged.<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>

*[[Colic Diagnosis - Abdominal Ultrasound|'''Ultrasonography''']] may reveal a markedly enlarged gastric echo extending over six or more intercostal spaces on the left side of the abdomen.  A marked increase in the thickness of the wall of the stomach may also be imaged.<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>