Originally Posted by Andy75

It must first be defined what we mean for EGO.
If for an EGO we define as a "mask" that we wear for dealing certain circumstance and, we pretend the others consider us as that EGO, and sometime we believe to be that EGO, so yes, animals have EGO for my point of view.
A lioness, on top of predator pyramid in certain environment, will consider all other animals like preys, so they behave in according to the EGO with other animals, but when it comes to deal with a lion, they have another EGO as they know that the boss is the lion and they cannot expect to eat before the lion.

Some dogs have huge ego and they can attack huge animals, like bulls or bear, even thought they are (partially) aware about they are weaker.