BTW, cats and dogs: I never realised this before, but that means Heinrich must have kept some at Rheinsberg, or people from his household did.

Evidently! I think I had raised an eyebrow at that when reading Ziebura, but then totally forgotten (has it really been almost a year? OMG), so thank you for the reminder! Since we don't hear about them from Lehndorff, I'm guessing they weren't nearly as important to Heinrich as the greyhounds were to Fritz.