I'm not so sure i know that animals can sense fear........but death?!
Yes, animals can sense the death of someone they are loyal too. I've seen it with my own eyes. When my uncle was passing on his dog wouldn't leave his side even when the nurses and doctor would come the dog would refuse to move and would grow. if he was pushed to the side. The dog didn't mind someone helping his master, but he was there up until the time my uncle died. After my uncle died the dog would disappear for a day or two and my father followed the dog one day and found the dog laying across my uncle's grave. This went on for several months so my father and the rest of our family would simply bring food and water up to the dog every evening. We knew better than to remove the dog from his master's grave site. Dogs and cats can grieve as well as many other animals.
Humans are ego maniacal and those that prefer to think they are of greater intelligence than their counterparts generally are so full of themselves they miss the point entirely. When you become your own biggest star and forget there is much to learn you have ceased to be intelligent. We should learn from animals and so far from what I can see the pets are winning!