Congratulations on your baby. I've only had my Cav for a month after waiting more than 10 years, and I just can't tell you how much these babies get right to your heart. I'd already mortgage my house and car to get him anything he needs. :?
I've only been on this board for a couple of days, but boy oh boy do I have a ton of experience with cats (I have 11, tho not intentionally, ppl keep dumping cats out here.) And with introducing new dogs to cats.
My Cav, Rudy, was easilly frightened at first. All of my cats are very accustomed to dogs, so tho a couple of them hissed at Rudy for a couple of days, they really weren't a threat to him. But it scared him, nontheless.
I really don't want to cause you undue concern, but I think you are going to have to take this introduction seriously. Your cat is old enough to be very mad about the puppy. Unless your cat has had some prior interaction with dogs, it is not going to be easy. Puppy is likely to want to play with Kitty like he did with his littermates. First thing puppy will probably do is run at the kitty like a big dumb floppy puppy. First thing your cat will probably do is knock puppy on his behind. Hissing and lunging, with claws bared.
It would be much better to bring puppy in in his crate, leave him there, and let cat walk around and check him out. Kinda ignore puppy and give lots of attention to cat. Then if you can, put cat in another room and pay attention to puppy. Re-crate puppy, let cat back in to observe puppy some more. I would let this process go for a full day.
Second day, have a family member, but not cat's primary family member, hold puppy and let cat sniff him, etc. Don't let puppy charge at cat. I'd do this for this full day.
Third day, let puppy on floor with cat in room, but restrain puppy. Let cat come to him. If you observe some comfort level, you can let puppy go and see what happens. Bear in mind that the cat could actually attack the puppy and hurt him, scratch his eyes, ect. And puppy could be really frightened and feel insecure. If cat demonstrates seriously hostile behavior toward puppy, put the cat in another room, letting it know that this behavior is not acceptable.
Do not feed at same time and don't leave cat food where puppy can get it. I actually feed my cats outside on the deck, on my patio table. Or on my kitchen counter.
Now all of the above is worst case. It is possible that your kitty will immediately take to the little guy and mother him. You will get a feel for that the first day when puppy is in crate. Is kitty hissing or is kitty reaching paws into crate to try to "cuddle" or play with puppy.
But if kitty is very hostile, and is a danger to puppy, always remove cat from the room. Let him know you will not allow this behavior. And always keep puppy in a situation where he feels safe. You may even need to keep puppy in crate while kitty is in room for several days.
Basically, you know what to look for and you will know when it is safe to let the two of them "touch" one another.
Of course a lot of things are unknown to me, like how affectionate your kitty is and how much time he spends with his humans. Weather or not kitty goes outside or is strictly an inside cat. And, of course, what kitty's basic temprament is.
One of my cats, who was one of the most affectionate of the lot, simply walked out the door the day the puppy came, and never came back. She was really done with dogs, I guess. She moved in with one of the neighbors, and is doing fine. Since she was a beautiful 6-toed cat, she wasn't at a loss for people who wanted her.
I hope that you find this helpful.
