Changes

==Prevalence==

==Prevalence==

Ileal impaction occurs most frequently in the southeastern USA, Germany and The Netherlands.<ref name="Merck">Merck & Co (2008) '''The Merck Veterinary Manual (Eighth Edition)''', ''Merial''.</ref>  In the southeastern USA, there appears to be an increased prevalence in the autumn which may relate to changing weather and feedng regimes at that time of year.<ref>Hanson, R.R, Wright, J.C, Schumacher, J, Baird, A.N, Humburg, J, Pugh, D.G (1998) Surgical reduction of ileal impactions in the horse: 28 cases.  ''Vet Surg'', 27(6):555-60.</ref>

Ileal impaction occurs most frequently in the southeastern USA, Germany and The Netherlands.<ref name="Merck">Merck & Co (2008) '''The Merck Veterinary Manual (Eighth Edition)''', ''Merial''.</ref>  In the southeastern USA, there appears to be an increased prevalence in the autumn which may relate to changing weather and feedng regimes at that time of year.<ref name="Hanson">Hanson, R.R, Wright, J.C, Schumacher, J, Baird, A.N, Humburg, J, Pugh, D.G (1998) Surgical reduction of ileal impactions in the horse: 28 cases.  ''Vet Surg'', 27(6):555-60.</ref>

==Aetiology==

==Aetiology==