JOHANNESBURG, Nov. 17 (Xinhua) -- There is an outbreak of rabbit hemorrhagic disease (RHD) in the Western and Northern Cape provinces of South Africa, said the Department of Agriculture, Land Reform and Rural Development on Thursday.

State veterinary services did post-mortems on dead rabbits and confirmed that the die-offs of wild rabbits and hares were a result of RHD, the department said.

"The occurrence of RHD in the Karoo is therefore of great concern, as our indigenous Red Rock rabbit, endangered Riverine rabbit and hare species are highly susceptible to this disease. At this stage it is still unclear how the disease could have entered the country since the importation of rabbits and hares is not allowed," said Reggie Ngcobo, spokesperson of the department.

Investigations are underway to determine whether illegal importation could be the source, he said, adding that this is the first detection of the disease in the country.

"Control of RHD in rabbitries relies mainly on vaccination, but the vaccine is not available in South Africa. This increases the importance of biosecurity measures in rabbitries and anywhere where rabbits or hares are kept," Ngcobo said, who advises rabbit owners to ensure that their rabbits are secured and must prevent any contact with other rabbits or hares, either directly or indirectly through people or equipment.

RHD is a disease caused by Calicivirus which is highly resistant and stable, even when exposed to harsh environmental conditions. Ngcobo said the carcasses of RHD-infected rabbits may be a major source for viral spreading, urging people to report any dead or dying rabbit or hare to the nearest state veterinarian for investigation.