"When she comes over?" Your partner doesn't live with you? If that's the case, the solution is easy - she doesn't bring the dog when she visits.
If such a simple solution won't work, I know a lot of this forum will disagree with me, but in my experience the only way to make the Frenchie stop is aversives, and even then it sounds like you let your cat outside, so it has the opportunity and may be smart enough to rehome itself. I used a squirt bottle with water on rescues with some success (squirt right in the face), but in some cases it took something stronger, like a mixture of water and lemon juice (which stings - I squirted it in my own face to see how much). I imagine a citronella collar would work.
However, IMO all you do is if the prey drive isn't so high the dog kills the cat before you teach it anything, you teach them to behave around the cat in certain circumstances. Remove those circumstances and the cat is in trouble. Never, ever leave the dog loose in the house with the cat no matter how well you think you've got them getting along. Because I was once naive about canine prey drive, I had the miserable, guilt-provoking experience of one of my cats being killed by a rescue I thought I had convinced to co-exist with the cats. Don't let it happen to your cat.
If such a simple solution won't work, I know a lot of this forum will disagree with me, but in my experience the only way to make the Frenchie stop is aversives, and even then it sounds like you let your cat outside, so it has the opportunity and may be smart enough to rehome itself. I used a squirt bottle with water on rescues with some success (squirt right in the face), but in some cases it took something stronger, like a mixture of water and lemon juice (which stings - I squirted it in my own face to see how much). I imagine a citronella collar would work.
However, IMO all you do is if the prey drive isn't so high the dog kills the cat before you teach it anything, you teach them to behave around the cat in certain circumstances. Remove those circumstances and the cat is in trouble. Never, ever leave the dog loose in the house with the cat no matter how well you think you've got them getting along. Because I was once naive about canine prey drive, I had the miserable, guilt-provoking experience of one of my cats being killed by a rescue I thought I had convinced to co-exist with the cats. Don't let it happen to your cat.
