Is there a way to keep my dog from being jealous of my new cat?
Give then time to get used to one another and give each attention out of view of the other if possible. They'll make friends, or at least tolerate each other at some point.
Kill the cat :3
Get rid of the cat
First of all, dogs cant get jealous. However, they can be threatened. Your dog may think the cat is taking over its turf. :P
<----- Keep it that way :)