Separate them for as long as possible, letting them sniff through doors. Keep one in the bedroom for awhile, with the run of the house, then switch off. Do this as long as possible, so the older cat can acclimate to the smells and sounds.

Do not let him ever get at your 10 year old cat.

Add some focused play, chasing toys, etc., with the kitten, because he is after all a rambunctious kid. I think aging will eventually help some.

Also try putting a dab of cologne that someone in your family wears a lot, on the forehead of each cat. Sometimes, when the odor is not as different, it dials down the hostilities a bit.

The neutering was the good idea, the declawing not so much. Does he bite? Is the older cat declawed also?

He is a kitten. My cats "attack" each other all the time. Sometimes they scream bloody murder and then we intercede.

You brought a young cat into a house with an old cat. They don't get along. It's one of the oldest pet issue stories around. Amputating his toes doesn't stop this.

The neutering was the good idea, the declawing not so much. Does he bite? Is the older cat declawed also?
Thank you Sue for saying this. This was my immediate reaction when I first read the post, but I did not want to raise this 'hot' topic again, as it was too late anyway.

It does take time and patience to introduce a new cat. The age difference will make it MUCH more difficult as your little kitten is full of energy and wants to play. Unfortunately older cats prefer their peace and quiet.. So Bob may need more interactive games and attention to keep him looking for this in your older Lizzie. As others said, protect her and go slowly.

Anne-Marie

I think the size of your home is also a consideration. A long time ago we had 4 cats in a very big house. Two were kittens and 2 were old. The kittens would gang up on the old timers occasionally, but there was so much room that they all could find their own space. It's important to let each animal have their own "turf" but the battles will probably continue to erupt occasionally until the kitty matures and settles down.