My older dog hates the puppy. The puppy WANTS the old dog. I'm going insane
I'm a few weeks into a new puppy (my second post here, I'm guessing there will be more). She's 13 weeks old, 3 pounds, and an absolute terror, but we can handle that. What I'm going insane about is that my old dog (Luna - chiweenie, 14, Cushing's Disease) prefers to pretend the puppy doesn't exist, but the puppy barks and jumps and loses her whole mind anytime she sees her. The puppy does go up for enforced naps and spends most of her time in a pen because she can't be around Luna.
(Background on how I got into this situation: seven months ago we were told Luna had probably 6 months left because she has cushings and had a seizure. Our younger dog is inconsolable without her, so we started looking for a puppy. Now we're a few weeks into a puppy and Luna is going strong with no signs of going anywhere soon. We thought we'd be a 2 dog household, but now we have a very old and grumpy dog, her younger brother who she only now likes after a few years, and a puppy she wishes would leave her alone.)
I'm keeping them 100% separated for the time being, but it makes everything SO much harder. Life is simplest when I can put the old girl up in my bed and she sleeps for a couple hours. The puppy can run around to her little heart's content, explore, play with our middle dog (almost 5 and loves her), and everything is pretty chill.
Inevitably, the old lady wants to come out and the puppy goes wild. Once Luna settles, the puppy will forget about her, but give it a few minutes and Luna will want to move four inches on the couch to a new spot. I can't have the puppy out without running constant interference because she hops along the edge of the couch and barks and I am in no way confident that Luna wouldn't go after her if pushed too far. I would LOVE to just have the puppy on one side of a baby gate and Luna on the other, but Luna will whine and bark to be let back in, even though she doesn't actually want to be anywhere near the puppy.
I honestly don't know how to manage this. I want the puppy to be able to roam around safely, but I want Luna to be included in the family, and right now I don't see how I can do both. Does anyone have any suggestions?