Has the cat ever been around dogs? It will take time, patience, and some training. My GSD chases all 5 of my cats, but most of the cats start with her first, they really all get along well. The cat will determine when and if the dog may approach it, yes the cat is in control. When I got my first cat, he HATED my oldest dog..he arched his back, his tail blew up, he hissed, growled, etc. My dog was very patient, but persistent. It took about 3 months and I finally caught them sleeping together. They are partners in crime and its always those two getting into something. Since then I have brought in numerous other dogs and 4 cats...the original cat gave everyone except maybe the last three a hard time. Every time an animal came in it took him less time to get used to it. Now I can bring anything home and he just don't care, he takes to them pretty quick.
Misty- Samoyed Mix, Tannor- Golden Retriever CGC
Robyn- GSD CGC, TC, Midnite-GSD CGC,TC, Brennan-Golden Retriever CGC, Batman-Husky/Greyhound , Apollo-GSD