1.
Illness. There
are a lot of
illnesses that
make dogs
aggressive.
The best way
to determine
what disease
may cause dog
aggression is
to talk to
veterinarian.
2.
Dominance.
Dogs often
show
aggression to
establish
their
dominance.
3.
Fear. If the
dog feels he
is in danger
and needs to
defend himself
he can show
his aggressive
behavior.
4.
Frustration.
It occurs when
a dog is
frustrated at
not being able
to get to
something.