Your other dog is a male, so that is a plus.
The cat thing might be problem. I had my two GSD girls and then bought a kitten. I've resigned myself to keeping the cat separate from the shepherds. Sage loses her mind when she sees the cat, and the cat isn't afraid of her. She's a delicate little Siamese kitty, and I just can't trust Sage not to run her down. I love them all, so I'm willing to put up with a little inconvenience to make it work.
~ Diane ~
RUSSELL .... Lauremi's Paix
CARLY ........ Ch. Lauremi's No Reservations (AKC GCh pointed, HIC)
and absent friends... SAGE ~ 2010-2015