From Ralf Hartemink's International
Civic Arms website: The new arms were granted on November 22, 1974.
The new arms show still the crosier from the old arms. The deer's head
is replaced by the antler, and the torch is added. The torch symbolises
the industrial area around Ingolstadt in the
county. The base is also added and shows the lozenges of the arms
of Bavaria. A large part of the new county belongs to Bavaria already
for many centuries.
Literature: [presumably Linder and Olzog
1996].