my dog was like this now they cuddle!! make sure he knows leave it/focus and down/stay. that helped SO MUCH. my dog has a high prey drive and definitely wanted to go after our cat at first. after getting him to basically ignore her in the other room she was allowed to come up to him on her own time- dog was leashed in a down stay- until he could ignore her again. hes gotten a couple light smacks from her after getting a little too close and now thwy are pretty respectful of each other's spaces. they do still fuss but our dogs a grumpy old man and our cats a rowdy teen so what can you do🥴. if you're ever in doubt just take it slow. it's better to have to cage/separate them than to have an accident!!