Management of caecal impactions

Caecal impaction is a rare form of surgical colic that constituted 0.45% of all horses that underwent exploratory celiotomy for colic at one university referral hospital. However, it is one of the most difficult colics to manage and can have a high mortality rate because of the risk of caecal rupture associated with impaction.
Despite previous attempts to classify this disease by type, there is no scientific or clinical evidence that such a classification is valid. In one proposed type of caecal impaction (type I), a dehydrated mass fills the caecum and usually causes moderate distention. In the second type (type II), a vague form of caecal dysfunction or motility disorder is reported, in which the caecum becomes markedly distended with ingesta that has a soft and fluid consistency. A proposed distinguishing feature between the 2 is a favourable response to medical treatment when the impaction is with dehydrated ingesta, whereas surgery is required for the caecum filled with liquid contents. If surgery is not performed promptly for this type of impaction, it will progress to rupture.
In the author’s experience, the same basic underlying pathophysiological changes probably apply to all manifestations of the disease, and the major difference between individual cases could relate to the degree of severity and possibly to the risk of recurrence. Risk factors are recognised but poorly understood for horses that are hospitalised for unrelated diseases; however, caecal impaction can also develop in horses that lack this risk factor. Another form of caecal impaction has been described in which only the cupola is involved and some of these horses can present with vague signs of recurrent colic. This lesion can be missed at surgery. Possibly, most if not all caecal impactions start in the cupola and caecal base where the impaction can obstruct caecal outflow and progressively lead to impaction throughout the remainder of the caecum. Caecal rupture is a rare catastrophic accident during parturition in mares, but is unrelated to the more typical forms of caecal impaction and associated rupture. […]