I've had Roscoe, my pup, about a month and he's 14 weeks old. Last Wednesday I pulled a stray cat out of a wooden electrical box on the side of my apartment building. I took her to the vet, no microchip, she's in good health, tested negative for leukemia/FIV and got her shots, just needs to gain some weight (she is very skinny atm). She has been fixed and her front claws were declawed. Obviously someone took care of her - I've checked around my complex and done some searching, and can't find anyone to claim her. At this point she's become my cat and I will most likely be keeping her unless her previous owner shows up. She's a flamepoint Siamese (most likely some kind of mix), and the vet said 1.5 -2 yrs old. She's very affectionate with people, very loving, and can be vocal.
Roscoe interacted with my brothers cats when we stayed at his place for a bit, he would try to play and they would be curious about him and swat him a little, but no rough play. He would bark at them outside. Now, with the new cat, he constantly barks at her. I have a one-bedroom townhome, and before Roscoe could climb the stairs, she would stay up there and he would hang downstairs. Now he chases her upstairs and will corner her somewhere and bark at her. Sometimes he'll dart in to lick and sniff her, but pretty much just barking. She cowers and growls, and will swat at him, but since she is declawed, it has no effect. I'm not worried about him hurting her or her hurting him (although she is still pretty skinny at this point, could get bad if he tries to play), but I'd like some advice on if there's anything I can do to get them used to each other. She's only been around a week or so. My boyfriend suggested just letting them go at it until they get tired of it, but I don't know if that's the best bet.
Roscoe starts puppy classes on Sunday - will this help me be able to better control him in this situation so they can quietly get used to each other?