Originally Posted by germanshepowner
I’m home with her all day so she gets a ton of exercise and training all the time. But even when she’s just come in from a walk, she fixates on the cats immediately. Sigh.
This may sound a tad counterintuitive, so bear with me. Unless you drive
to and from the place where you talk your walks, she's coming in still excited by (wired from?) the walk. The walk may have taken some
of the edge off, but if it was enjoyable, it probably also was exciting. IOW, the engine's still running --- especially if she saw or encountered SQUIRRELS during the walk. So, of course she fixates on the cats when she comes in. You've warmed her up. [IMG class=inlineimg]/forum/images/Germanshepherds_2016/smilies/tango_face_wink.png[/IMG]
Consider crating her as soon as you come in from walkies. Don't unleash her, just take her to her water dish, then directly to the crate, and put her inside with a treat. You could say (in a happy voice), "Place or Nap Time!" Or some such thing. Leave her there to rest and remain quiet for 20-30 minutes. Your goal here is to teach her that exercise/training is followed by quiet periods (aka self-control) and that focussing on cats (excited or not) is a nonstarter.
Next, during your training sessions, work on teaching and proofing the "leave it" command. There are lots of good youtube videos on this. It's a handy tool to have and, over time and with consistency, generalizes well to a wide variety of temptations (including cats), at home and outside.
Finally, make sure that the cats have a good escape route in every room of the house. You may need to gate off several rooms (or floors) to limit the pup's access until she learns that cats aren't to be chased. Or, make sure that the cats have easy access to stable heights that the pup can't reach (e.g., secured bookcases). Worst case scenario, while the cat escapes, you can practice your "leave it" command with the pup. Best case scenario, you intervene with the "No! Leave It!" and "Come" commands the second before the pup starts her laser-like death stare. That's hard to do at first, but your best success will come from early interventions like that.
ETA: I've always had dogs and cats. The combo has worked (with one exception) because I insist
that the dogs NOT pay attention to the cats. It may seem like benign interest now, but it can quickly turn unfortunate until acceptable behaviors are firmly established. Even if the interest is playful, keep in mind that the size differential can lead to tragic consequences. Best to intervene/train now, before that disparity grows larger.