Introducing Puppy and Cats

I am heading to my parents house for the first time with Bella this weekend. My parents have two cats - one is a total scaredy cat and will surely run and hide at the sight of Bella. The other is a rough and tough cat who loves to hunt, will hiss, scratch, etc if you get on his bad side. He beats up on the other cat sometimes. I am very nervous to introduce Bella to Jasper as I'm afraid he will lash out at her. Any suggestions here for the best way to introduce them? We will be at my parents house Sat through Monday so I don't think there is a way to just keep them apart the whole time. Plus, we travel to my parents for weekend trips fairly often so they need to get used to each other at some point. Thanks in advance!

It depends really on the cat. We always used to allow next door's cat into our house until Daisy arrived.Unfortunately the moment the pup made a sudden move, the cat leaped upon her, grabbed her from my arms and tossed her up in the air and tried to kill her. He's made several attempts on her life since then and the poor cav is so friendly any time she sees him she races to him to play.I really think separate them and never trust a cat, even for one second.Cartainly never leave them on their own.Cats are very territorial and have no problem attacking a small dog.A cat loving friend of mine suggested getting a water pistol and any time the cat made a sinister move toward the dog, squirt it with the water gun and say "No".
The cat has now gone back home to his owners but we daren't leave our pup in the garden alone at any time.
Sins

Don't even consider introducing a puppy to a cat that may lash out in any situation where one can go for the other. All introductions need to be totally controlled -- the cat needs an escape route and the puppy should only be on a harness and lead and never allowed to chase. A puppy WILL think a cat is a toy and a running cat is something to pursue -- and it could end very badly. I would not even let them go very near each other. A cat can remove a dog's eyeball or blind it with a swipe -- there are two members here with dogs who had this happen -- so this is very important.

You could let the cat come investigate the puppy while the puppy is securely crated. This is a good way to do initial introductions so that the cat can feel safe and the puppy is kept safe. They need time to smell each other and get sued to each other.

Intriductions between cats and dogs always need to be very cautious, very controlled, and done over time with patience.

Cats and Cavaliers: how to do introductions between cats and dogs: http://board.cavaliertalk.com/showthread.php?t=8862

My three dogs live with four indoor cats though and the boys have been happy foster 'parents' to several litters of foster kittens so a lot depends on the dog, the cat/kitten, and taking the time to do introductions slowly and carefully. Some cats and dogs will never get along though and it is dangerous to allow them near each other.