A sign in honour of Charlie at a candlelight vigil in late October. © Coalition to Ban Horse-Drawn Carriages
Charlie, a 15-year-old draft horse, collapsed suddenly and died on October 23.
The Cornell University College of Veterinary Medicine was asked to conduct a complete gross necropsy and histopathology of all body tissues, special stains of the liver, heart and brain as well as a parasitology analysis.
None of these indicated a direct cause of death.
The necropsy revealed a significant amount of tissue breakdown after death.
Though the visual examination of the stomach showed gastritis (inflammation of the stomach), much of what was seen visually may have been the result of tissue breakdown after death.
There was no evidence of gastritis in the microscopic sections of the stomach, though tissue breakdown may have obscured subtle abnormalities. A firm area of the stomach noted visually was a result of muscular enlargement rather than scarring.
The presence of inflammation in the small intestine and a nodule in the large intestine both indicated parasites. However, these findings were not severe and, given the good nutritional condition of the horse, were not causing significant problems.
The liver had evidence of scarring but the cause of this is unknown. However, it has been reported in cases involving heart conditions. No abnormalities were seen in the heart.
In this case, the liver scarring was chronic and of unknown clinical significance.
The cause of death in the horse remained unknown and there was no evidence of a sudden onset of any abnormalities to account for the collapse.
It is possible that the horse had some degree of a heart condition, those performing the necropsy found, but this could not be conclusively demonstrated.
They could not rule out recent toxin exposure, abnormal heartbeat or allergic reaction as the development of changes in tissue requires that the animal remain alive for at least 12 hours after the event or exposure.
The preserved sections of heart were examined microscopically and no abnormalities were found. No additional microscopic examination is necessary.
The ASPCA said the case was now closed.
The case has been surrounded by controversy over early findings around the horse's health, which fueled ongoing debate around the carriage horse trade.