"There is only a proportion of the animal population here that is susceptible to the disease, but it is not entirely clear how much of the animal collection would have to be culled should the outbreak reach Edinburgh Zoo, " he said.

BBC: Zoo reopens after disease scare

The World Organization for Animal Heath reported in January that Chinese authorities culled 948 pigs in southern Guangdong Province after an outbreak of foot and mouth disease there.

WSJ: Floating, Dead Pigs Repulse Shanghai