In chapter 21 the sheep break into a field of clover, which causes their bellies to expand. The flock is in danger of dying, so Gabriel Oak has to lance their stomachs at a certain point to let the gas out. Is too much clover or vetch dangerous to sheep? Does lancing their stomachs cure them? I would have thought pricking a hole in a sheep's stomach would cause perotinitis or blood poisoning.

