I have a whole chapter in my book about pets dealing with people's and other pets' deaths! So there are a lot of rumors/pop culture ideas that a dog or cat will eat an owner's dead body, but research has shown that doesn't happen nearly as often as people think. If an animal is starving and trapped in the house for weeks, maybe, or sometimes a dog will become distressed and try to "wake" an owner up and then chewing/gnawing can happen, but mostly it seems that pets seem to understand death in their own way. If an animal gets to view their owner's body, they seem to get that the owner is not coming back. The most heartbreaking stories for me are the ones where a pet doesn't understand the owner is dead and keeps waiting/hoping, like Hachiko in Tokyo: https://en.wikipedia.org/wiki/Hachik%C5%8D.