when i got the puppy, Zack, in january, my cat Fluffy was over 13 years old. There was no expectation that Fluffy would like Zack. The question was, how bad would it be? A few months before, my daughter's cavalier Belle was here to visit and she left Fluffy completely alone, so that worked out fine. Fluffy is not aggressive. She is kind of a shrinking violet, and will run away rather than fight.
But Zack wasn't like my daughter's cavallier about Fluffy. He is much more sociable with other animals than Bellle. He just wants to play. So, he would jump at Fluffy, the way puppies do with each other. Now, 4 months later, he still has the impulse to jump at Fluffy and try to get her to act like another puppy--and that is never going to happen. I have corrected him consistently the entire time, but while he is very compliant about most things and responsive to correction, he has seemed just overwhelmed by his urge to play with Fluffy.
But now there has been an improvement. A few days ago, instead of just verbally correcting him while blocking him from lunging at Fluffy, i escalated the correction by getting up, growling, snapping at him, and then when he laid down on his back, i bit his muzzle--softly, not to cause pain, but to make a dramatic point. I had never done that before but had read it in a book which recommends taking on the role of the mother dog. It worked. He has been much better, dramatically better, not lunging at all, though still appearing to want to, but so much calmer. the difference is undeniable.
Fluffy sees the difference and she has begun to actually show a lot more comfort with him, for example, i looked up a couple of days ago and they were laying on the floor about a foot apart. Previously the only time they'd stay near each other was if they were sitting with me on my reclining chair. The difference was that Zack wasn't lunging or overly excited, so Fluffy didn't retreat to her little hidling spot behind another chair. then, i saw them laying near each other on another spot and Fluffy was playing with one of Zack's toys. This has never happened before, and Zack was watching intently. If this had been another puppy, he would've wanted to play tug o war with the toy, but instead he just watched, containing his excitment. I have been praising him a lot when i see him acting this way.
Another thing in the last few days is that Fluffy has allowed Zack to lick her, including affectionately giving her a few licks on the ear yesterday. This is really radical. Before this, Fluffy was very uptight if Zack made any contact with her except when part of his body would be laying on her when the three of us were sitting together. And then, twice now when we were sitting that way in the past couple of days, Fluffy licked Zack!!!! wow! she licked his fur, on two separate occasions.
From the beginning, Fluffy would try to avoid Zack when he was harrassing her playfully, but if he went too far, she would swat at him, and if necessary, she would chase him and would hiss and make an angry cat noise and would bite at him. he would act completely intimidated, would run away and would then leave her along for the time being. She did not appear to be trying to hurt him, her claws didn't seem to be open, but fortunately this was always effective and he would always stop right away when she did this. If he were to keep going at her, i think she would attack more seriously and hurt him, but i've seen no sign that he would do anything but run away as soon as she swats him or tries to chase him. Fluffy is not very agile. She is a small cat, she was once 9 pounds as an adult, but in the past year, she has become obese and more recently she limps in a stiff arthritic way off and on and i am trying to learn what to do about it.
when i got Zack i placed a baby gate on the stairs and for a lot of the time, i kept them separated. When i wasn't home, Zack has been first crated, then penned, then loose in the kitchen, and now, he has the run of the downstairs of the apartment when im not home. I keep Fluffy upstairs. I've started leaving the baby gate open when i am home. This is such a gradual process but after i saw the mutual licking between the two and how they laid quietly near each other on the floor, i am wondering what the possibilities might be.
I still think that Fluffy could hurt Zack if he was lunging at her so i don't want to leave them both loose in the house when i'm not home, but i feel bad about Fluffy having to be confined for so many hours, i think she gets even less exercise when she stays upstairs, there's nowhere for her to go up there, jsut her little cat bed and her dishes and her catbox. Fortunately they sleep a lot.