PROSPECTIVE-STUDY OF EQUINE COLIC INCIDENCE AND MORTALITY

A prospective study of one year was conducted on 31 horse farms to obt ain population based estimates of incidence, morbidity and mortality r ates of equine colic Farms with greater than 20 horses were enrolled b y randomly selecting horse owners from 2 adjacent counties of Virginia and Maryland. Descriptive information for 1427 horses was collected a t the initiation of the study and updated at 3 month intervals, Time o n the farm during the study was tabulated for each horse, When colic w as reported by the owner, investigators visited the farm to obtain inf ormation about the colic, The crude incidence density rate of colic wa s 10.6 colic cases/100 horse-years, based on 104 cases/358,991 horse-d ays, The median farm specific incidence density rate was 7 cases/100 h orse-years, and the range for individual farms varied from 0 to 30 col ic cases/100 horse-years, A specific diagnosis was not made for 84 (81 %) of colic episodes, Seventy colic episodes (67%) were treated by a v eterinarian, Drugs were used in 83 (80%) colic episodes, and 78 (75%) of colic cases were mild, requiring no treatment or resolving after on ly one treatment, Four horses required colic surgery, Fourteen (13%) h orses had more than one episode of colic during the year, Mortality fr om all causes of death was 2.5 deaths/100 horse-years, mortality rate for colic was 0.7 deaths/100 horse-years, Proportional mortality rate of colic, 28%, was higher than for any other cause of death, Horses le ss than age 2 years or greater than age 10 years had lower incidence t han horses age 2 10 years. No difference in cone risk between genders was identified, Arabian horses had the lowest and Thoroughbreds the hi ghest breed specific incidence rates, Horses used for eventing, or in training had a statistically significant higher incidence rate of coli c compared to mature horses with no use (pets, retired, an pasture wit h no stated purpose), Horses used for lessons or with no use had the l owest incidence rates.