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 in Okla
Carly ~ AKC Champion, GCh pointed, HIC
Sage ~ AKC Ch. pointed (13 pts), HIC
Russell ~ the big dog
Mimi & Pi ~ the meezers