The advice was provided following a meeting of the chief veterinary officers from around Australia at which it was noted the AusVetPlan states any horse which has been confirmed with positive test results to Hendra must be destroyed.
The AusVetPlan is a nationally approved set of best practice policies for responding to emergency diseases.
The meeting also took advice from medical authorities and an expert group reviewed current scientific information about the risks associated with recovered horses.
Biosecurity Queensland's Chief Veterinary Officer, Dr Ron Glanville, said there is a real risk the horse could relapse with the disease in the future and pose a risk to other horses or humans.
"The AusVet plan is very clear on what is required, to prevent any further spread of this highly fatal disease. In these cases, human health and safety must come first," Dr Glanville said.
"In the interests of protecting people and horses from further infection, euthanasia is the most appropriate response," he said.
Biosecurity Queensland, a specialist unit within the Department of Primary Industries and Fisheries, has been managing the response to the latest Hendra Virus outbreaks, at Redlands and Proserpine, in cooperation with the owners of the animals involved, local veterinarians and a range of stakeholder organisations.