Results have confrmed that Rigo's death was casued by sudden heart failure.
The Zoo’s Head of Veterinary Services, Dr. Michael Lynch, explains that Rigo’s heart tissue showed changes consistent with a degenerative condition known as hypertrophic cardiomyopathy, a disease which can only be managed, not cured.
Melbourne Zoo will collaborate with a USA-based research group investigating cardiac-related deaths within the world-wide gorilla breeding program population to further assess these findings.
Hypertrophic cardiomyopathy is not uncommon in male gorillas over the age of 30, and in many cases there is no sign of the disease until the individual suddenly collapses and dies, as was the case with Rigo.
Rigo had cardiac ultrasounds in 2007 and 2009 which showed no abnormalities, and he presented no clinical signs such as exercise intolerance or shortness of breath.