My puppy likes to bark at my rabbits, so I know what you mean about the high pitched bark. The rabbits are behind a gate, so he can't get to them, but when he gets excited enough he'll bark out of frustration. When he does this, I give him a two strikes rule. First, I ask him to "leave it" (or you could call your puppy back to you) and ask for a sit or a down. If he runs back and barks again, I remove him from the situation by gating him into a room far enough away that he doesn't bark. Sometimes, if I feel like actively working with him, I will let him back to see the bunnies when he's quiet, continuing to remove him when he barks. Other times I just remove him for a longer period of time until he's settled down.
If the cat keeps coming back, I would shut the cat into another room or part of the house, or shut the dog into another room. Don't make it like a punishment - I would go with the dog, to show him that he can't see the cat if he's going to bark, but it doesn't mean he'll be isolated either. You can then use access to the cat as a reward when he's being calm.
If the cat keeps coming back, I would shut the cat into another room or part of the house, or shut the dog into another room. Don't make it like a punishment - I would go with the dog, to show him that he can't see the cat if he's going to bark, but it doesn't mean he'll be isolated either. You can then use access to the cat as a reward when he's being calm.