The woman said the horse was found covered in blood. A small group of wild or feral horses is known to frequent the forestry area behind Kaitangata.
Since the death of the young horse, the larger group of horses had not been seen, despite searches for them.
The woman was worried some of the other horses in the group may have been shot or injured as well.
Earlier in the year, another horse was intentionally run down by a vehicle and its back leg was injured. The horse was put down.
Although this incident was unrelated, the woman said this sort of treatment was unnecessary and cruel.
"It needs to stop. Enough is enough."
The horses were not for target practice and needed to be seen as living animals, she said.
The Kaitangata Wild Horse committee had been informed of the incident.
- Otago Daily Times