Livers of predators are generally not safe, herbivores are fine as long as not eaten to great excess. Polar bear liver is known to be poisonous to humans in relatively small quantities (~10 grams), Eskimo would bury the livers when on a Polar bear hunt to stop their dogs from eating it.
Lorenzo the Magnificent wrote:
Try to find some stuff on Australian explorer Douglas Mawson and his ill-fated mapping trip in Antarctica. His story is fascinating. He ate dog liver, and the results were disastrous.
True. However the toxins are stored in the fatty part of the liver. You will eat some of the toxins if you eat liver, and they are not good for you.
The liver is basically a waste treatment plant....lots of toxins.