Right ventricular hypertrophy with heart failure in Holstein heifers at elevation of 1,600 meters.

A syndrome of progressive right-sided heart failure occurred among yearling Holsteins at a heifer-raising facility and 2 dairies on the Colorado Front Range between 2007 and 2011. Most cases were seen at the heifer-raising facility, where the disease ranked second only to pneumonia as a major cause of death in animals aged <1.5 years.