Abnormal Heart Rhythms Found in Post-Surgical Horses

Abnormal heart rhythms (arrhythmias) have been found fairly commonly in horses that have undergone surgery for colic or other gastrointestinal problems. A study conducted at the University of Liverpool showed that horses having surgeries of other kinds also frequently showed abnormal heart rhythms.

In the study, heart monitors were put on 67 horses that were admitted to the university clinic for exploratory colic surgery and 37 horses admitted for orthopedic surgery. The average age of the horses was 11 years.

More than 80% of all horses had some type of irregular heartbeat after surgery. The incidence was no higher in the abdominal surgery group than among those horses having orthopedic surgery. All horses returned to a normal heartbeat pattern without treatment.

Abnormal heart action after colic surgery has been thought to be caused by electrolyte imbalances or infection, both of which can cause arrhythmias in humans. However, the results of this study suggest that the intrinsic nerve signals that cause the heart to beat are being affected by general anesthesia.