Why is it animals can feed on carrion, whereas we get sick so easily?

Buzzards and other carion feeders have different bacteria loads in their stomachs which allow them to break down the nasty stuff and kill any harmful bacteria.

They do sometimes become ill.... eg. if a mountain lion eats a prairie dog that has rabies, the lion will get rabies.

http://zoocrewkids.blogspot.com/

When humans started cooking their food we didn't need to have the special enzymes and and intestinal structure to break down bacterias and germs. When we started cooking the cooking killed the germs and the bacteria for us. Our body didn't need to produce special enzymes to kill the germs. So it stopped producing them. That trait moved on to other generations so we are very susceptible to food poisoning. The same goes for when shoes were invented. They protected our feet to where our feet didn't need to be so tough. So now are feet are soft and can be easily cut now. Cooking is like the invention of shoes. They made are lives easier but also made humans weaker. It would be very hard for us to go back to eating raw rotting carcasses. Our bodies have been so used to not producing the enzymes for so long that they might not recognize how to break down the germs in the food.

More the former I think. Some animals are adapted to eat food even if it is decomposed. Their chances of survival are enhanced that way, in times of scarcity. I suppose in extremis some humans could and would eat that stuff too.