A bear is quite the paradoxical symbol because of the multitude of different things that it can represent. On the one hand bears are thought of as being ferocious and territorial.
Dreaming of a dead bear means you do not have much to worry about anymore. You can get away with making sure that you do not have to think about bears anymore. Also bears are known for being fearsome and ferocious creatures; if you can get away from a bear at night then you should be able to get away from a bear during the day. Basically, bears are scary, but if you only have to deal with a dead one then you should be fine to live on outside of this. Have no more fear.
The bear is known for being fiercely territorial and thus to have a dream about a dead bear could mean that the territorial part of you is dying. In many cases this can be a good thing because it means you are more open to meeting new people and having new experiences but in the worst of cases this can also mean that you are losing a much needed part of yourself at a time when it is essential, such as motherhood where you must always be protective of your children from outside elements, or a relationship in which you need to make sure nobody tries to seduce your significant other away from you.