Equine Colic: a Real Pain in the Gut - Prevalence

Prevalence
Determining the incidence of colic can help determine if colic on farms or in stables is excessive. Out of 100 horses in the general population 4-10 cases of colic is expected during one year (1,2). The annual number of colic cases, however, may vary greatly between farms, ranging from 0 to 25 or 30 cases per 100 horses (3,4,5). Approximately 10-15% of colic cases occur in horses that have experienced previous episodes of abdominal pain with 2 to 4 colic episodes per year in some horses (1). Most colic, 80-85 % of cases, can be designated as simple colic or ileus because no specific diagnosis identified and most horses respond to medical treatment or resolve spontaneously. In one cohort study approximately 30% of horses with colic were identified by owners but never seen or examined by a veterinarian because the colic was transient or resolved by with owner treatment (1). Studies of horses with colic that present to veterinary practices have also reported predominance of simple obstruction or spasmodic colic with impactions diagnosed in approximately 10% of affected horses (6). Obstructing or strangulating diseases which require surgery represent only 2-4% of colic cases though some risk factors in certain populations may increase this rate (7).

Colic is responsible for more deaths in horses than any other disease. In the normal farm population, horse mortality from all types of colic was 0.7 deaths per 100 horse-years with a colic case fatality rate of 6.7% (1). The predominant reasons for death were stomach rupture, strangulating lesions or enteritis (8). The true incidence of specific intestinal diseases causing colic in the general equine population is not known. Studies of horses presenting to veterinary teaching hospitals or practices for evaluation of colic rank simple colic and impaction colic as the most common diseases. The large colon is the most commonly affected followed by the small intestine, cecum and small colon, respectively (7). Large colon volvulus is the most common cause of strangulation obstruction, with strangulating diseases of the small intestine causing the highest case fatality rate (7,9,10). [...]