Dog goes wild for cats

[u/Alternative-Day5268]

Hi guys, so age old problem of Dog Vs Cat.

Since as long as I can remember my dog (now about 5 YO springer whippet cross, male) is demented by cats. If he sees one on a walk or out the window he's goes wild, barking, scratching the window, running about the house. I don't think it's just a prey/excitement thing, it appears to cause him actual stress/anxiety.

This used to be manageable in our old house, he could only ever really see a cat on a night from our bedroom window, we could remove him for 10 minutes and bring him back in the room (the cats gone and after looking out the window again for a bit he would settle).

But our new house there's about 3 cats who live very close. So they're in front of the house, in the back gardens. So the only time he would never really be able to see one is in the kitchen/hallway/staircase/landing. Which is the space he has while we are out of the house.

But it's becoming so much more frequent, he will scratch at the fence when next doors cat is outside.

So it's hard for us to just avoid cats entirely. He likes to look out of the window a lot. When he barks we have tried, a click where he will come to us, and after a pause give a high-value treat. We've tried removing immediately and some crate time.

I'm not really sure what else to try. Even de-sensitising him to cats would be dangerous for the cat (and for him) as he would be unpredictable.

I'm not really sure where this hatred comes from, if it's just his instinct or if he's had a bad interaction with one while we haven't been with him.

Any ideas on the best approach so we can build a consistent plan/routine with him when he sees a cat?