Concern over potential effect of rabies on Western Cape marine ecosystem

After a third seal tested positive for rabies in the Mossel Bay area, the Western Cape Department of Agriculture says it is concerned about the potential impact of rabies on the marine ecosystem and seal population.

Dr Greg Hofmeyr, who is the curator for marine mammals at Bayworld in Gqeberha and a seal biologist, told the Mossel Bay Advertiser there is a theoretical chance whales and dolphins could contract rabies if bitten by rabid seals.

The third seal, found on the beach at Tergniet, east of Mossel Bay, on August 25, was picked up by Stranded Marine Animal Rescue Team (S.M.A.R.T.) after the organisation received a call about the animal behaving strangely.

S.M.A.R.T. spokesperson Val Marsh says she and a volunteer responded to the call and went to the beach.

Once the seal was safely captured in a crate, it became very aggressive. It was then taken to Hartenbos Animal Hospital.

Dr Anthony Creighton, a veterinarian there, says the seal was monitored, then darted using injectable anaesthetics, and humanely euthanised. He says this was after a joint decision by himself and veterinarian Dr Frans de Graaff.

Dr Creighton said: “The decision was based on the clinical signs observed which, unfortunately, closely related to rabies infection. The seal displayed signs of aggression, especially towards humans (very abnormal behaviour) or fearless behaviour, attacking humans and inanimate objects, vocalisation through barking and growling, and showed neurological signs: head shaking, restlessness, continuous swallowing and uncoordinated movements of the flippers, neck and body.”

Department of Agriculture spokesperson Mary James says multiple seals have tested positive for rabies in several locations in the Western Cape since the outbreak was first detected in June. She says there is a concern about the unknown impacts on the marine ecosystem and the seal population.