My daughter has just moved back in with us (UGH, love her but she's a slob) and this time she brought her dog with her. The dog is actually awesome, she is a 9 month old Besinji mix. She is pretty good when I bring her in for a little while the problem is my cat. He is the real owner of the house and is not fond of the dog at all. the dog is pretty mellow around the cat and ignores him or is friendly towards Meow Mix(cats nickname) but whenever the dog is in, Meow mix will hiss and try to go after her, luckily kitty is declawed so he hasnt actually hurt the dog. Is there any advice for what I can do. My hubby suggested locking them in a room together to get them used to each other but I am pretty sure my cat can beat the dog up (kitty is about 22 pounds) so I dont want to do that. Anyone else gone through this problem. My daughter says she is only going to be here a little while , just til she gets an apartment, but most of us know through experience that she may get an apartment but I will probably end up with the puppy for the rest of my life so I figure the cat and dog need to learn to co-exist. Thankns Ya'll. =)

Cin is right.  Introduce them slowly.  But, since they are already together, kitty will adjust.  I would not leave them alone together if no one is there to supervise.  The big concern is when the dog is the aggressor.  Kitty will calm down and they may become friends.  Puppy's are big goofy troublesome creatures to cats.  The hissing is just her way of claiming her territory. 

Put a leash on the puppy.  Put kitty up higher than the pup.  Let them sniff each other.  If the puppy gets too playful, pull him/her out of the room until calm and try again.  This will let your cat know the puppy is not a threat to her/him.

Like I said, as long as the dog is not being aggressive to the cat, that is 1/2 of the battle.  You should still not leave them together, unattended for a while.

Good luck!