I have two cats. At first they were a little jealous but then they turned around and became even more friendly and they will even play with the puppies which is hard for them at times since the puppies or so full of energy and don't know when to stop. I have always had cats and dogs at the same time and have had no problems with them. Just let your cat know that you will still love him the same and spend the same amount of time with him. I don't think you should worry about it.
