Changes

*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses.  Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.   

*Enteroliths, stones consisting of magnesium ammonium phosphate around a central nidus (often a metallic foreign body) occur mostly in horses.  Typically, they lodge at the pelvic flexure or the transverse colon and affect horses greater than 4 years of age.   

====== Impaction ======

====== Impaction ======

*Impaction of the colon can occur in all species.   

Impaction of the colon can occur in all species.   

*In the dog and cat, dehydrated faecal material is the main cause of impaction.  

*In the dog and cat, dehydrated faecal material is the main cause of impaction.  

*In the horse, faeces, digesta, sand, or fibrous material can all contribute. Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility. *Antihelminthic administration or large parasite burdens can also lead to impaction.

*In the horse, faeces, digesta, sand, or fibrous material can all contribute to impaction Predisposing factors include poor dentition, water deprivation, a high roughage diet and general debility.  

*Antihelminthic administration or large parasite burdens can also lead to impaction.

====== Extrinsic ======

====== Extrinsic ======