Hi Pammy,
I saw your warning about "treat before leaving" and had to post. I'm on the opposite side, but it could be because my dog's neurosis came much later in life ;)
My Cocker mix had terrible anxiety anticipation after she hit a year old. She'd come down while I was putting on shoes, stare & moan. She'd moan (loudly) and then when I just left, run up to the window and "scream" after me. Very embarrassing & stressful for all of us. I tried pretty much everything to have her not focus on me leaving. Sneaking out, distractions, etc....but she's a very smart dog and my husband was louder in his leaving preparation than I was. About a year of various methods to stop this, I surrendered the war.
Everything is calm now. I fixed her anxiety ever since I started alternating between pig ears/ or basted chewies or dog biscuits. I gave her something to think about other than my departure. (which type depends on how long I'll be gone).
Now she waits and watches patiently while I get ready, but you can see the eagerness build up. She knows she'll get a "biscuit," "pigear," "chewie," or "ride"/"walk". And yes, they know what each word means (each understands somewhere around 50 words). When I finally ask "Would you like a biscuit?" They do happy dances all over the place. She still doesn't like that I leave, but she has something to do while I walk out that door. If she doesn't, her "buddy" will take it away. Then I just quietly leave & don't make a production.
If I return and then leave again, no extras. They accept the rule. I can leave without any upset on either part. Since I only feed them in the evening, leaving them with a little "something" helps out their tummies. They're at the correct weight, well muscled, and hey, everyone is happy.
When it gets really wierd is when I return sometimes hours later and she has protected her pig ear without eating any of it. This also happens when we've left them in the car together. She's hidden it away and immediately starts munching in happiness (because the pack is together? -- I have no idea why)
I guess this works for me & my little world. My life is much easier and she's less stressed. No more worries about a seizure being set off because her doggy psyche is overloaded. I don't advocate it for everyone, but it is an idea for some situations. :D
Good luck with your cute puppy
toodles