Hello so my cavapoo 4 yr old named poppy(black one) , has been constantly chasing my cat and barking at her. She never did that before like when she was 1-2 1/2 years old. And then randomly out of the blue she just started getting aggressive towards her, not necessarily like biting and stuff, but chasing her and barking constantly. I’ve tried using a bark collar that plays a loud noise and it works. However only when it is on her after that she just goes back to the same behavior when taken off. Not to mention she literally trembles like I’m hitting her, or like it hurts her when putting it on.(i and anyone in my family has never ever hit her once, and we don’t use the shock or vibration only the loud noise) Then I researched how to fix this behavior and tried using treats and the look at me command to “distract her” and teach her to ignore the cat for treats. It’s not working. It’s driving me crazy and I don’t know how to fix this. I don’t want my dog to have to constantly wear the bark collar because it scares her but it’s the only thing that stops the behavior. Please does anyone have any advice to fix this.
Also side note she’s been playing a bit aggressive with my other dog (the tan one) every now and then, such as nipping at his ears and chasing him into his kennel. She was such an angel before, I don’t understand why she’s acting like this.