A female white rhino calf born three days ago at Werribee Open Range Zoo has been euthanised after she contracted an “aggressive bacterial infection”.

The Zoo announced the sad news on its website, saying staff were “deeply distressed” by the loss.

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“Veterinary staff made the very difficult decision to euthanise the calf yesterday afternoon after an endoscopy revealed that an aggressive bacterial infection had caused irreparable damage to her stomach,” the Zoo said.

The calf contracted the illness from her mother at birth and was unable to recover despite antibiotic treatment.

“When we examined the rhino calf under anaesthetic we found that the damage to her stomach was so severe that any attempt at surgery would only prolong her pain” Senior Veterinarian Dr Sally Rourke said.

“This is when we made the heart-breaking decision to end her suffering.”

Director Sally Lewis said the death of the calf was a “huge blow” for the Zoo.

The calf was yet to receive a formal name, but zookeepers nicknamed her “Salt” as a nod to her sister, who was nicknamed “Peppa” after birth.

The calf’s mother, Si Si, and her sister are alive and well.