Reddit mentions of Comfort Zone Adaptil Spray for Dogs, 60 mL, for Dog Calming

Does your dog get Xanax 24x7 or only one dose per day, before you leave? If it's just one dose, there might be room to increase your dog's dose based on the information I've seen - speak with your vet before trying it, however.

Are you finding it helps at least somewhat? Xanax is in a class of drugs called Benzodiazepines that are effective for short-term anxiety relief, but there is individual variation, and sometimes they even have the opposite effect. We tried our dog on a different Benzo (Clonazepam), and instead of relaxing him it just made him hyper!

I also just re-read your original notes and I'm wondering, did anything happen back in February or March which could have triggered this new behavior? Any construction noises or building cleaners which may have spooked your dog?

My experience with veterinary behaviorists in moderate cost-of-living locales is that they charge about $150-$200 per hour, with the first appointment typically lasting 1.5-2 hours (the first appointment might be a flat fee.) This usually includes prescriptions and email follow-up for three months. Subsequent appointments are an hour, and similarly include three months of follow-up.

After our first behaviorist appointment, we received three new prescriptions, and we then tweaked the dosage via email back-and-forth over the next three months. It seemed like a small fortune to us before our first appointment, but we left feeling it was money well spent.

Beyond the medications you are trying, in the "couldn't hurt to try" department, you could try putting a dog-appeasing-pheromone (DAP) diffuser near where you want your dog to feel comfortable hanging out, and you could also use a DAP spray on his bedding and any other location where you want him to feel relaxed.

Usually I'm not a fan of products that might not have been rigorously tested (I was worried DAP was pseudoscience), but our behaviorist said there is some evidence to show that they help, and they can't hurt.

Final thoughts:

Is your dog a good eater overall? Is your frozen kong full of high-value food that your dog loves? If he loves it ordinarily but isn't always eating it when you leave, that could be a sign he's too anxious to eat. If so, then he probably needs more or a different medication. He needs to be relaxed enough to realize that you leaving isn't a big deal, and then he realizes he also gets an awesome kong to eat, it should build some positive associations with you leaving.

One tip from our behaviorist that helped us: when our dog is very nervous, the frozen kong isn't rewarding enough to distract him, especially straight out of the freezer. Her suggestion was to partially fill the kong (say 3/4 or even just 1/2 full) when freezing it, then fill the top 1/4 with something unfrozen and yummy (peanut butter, yoghurt, etc.) The unfrozen food is easier to eat and more rewarding, and then by the time he gets to the frozen part his anxiety level has improved so he'll continue eating the kong (plus it might have defrosted slightly by this point, which makes it more attractive).

The downside to this is he'll eat a kong faster, so a variation on this is to leave TWO partially frozen kongs. (Adjust meal size as appropriate so he doesn't get fat!)

This could also help with the door issue - if your dog is eagerly eating his kong he can't try and follow you out the door. In addition to the kong, you could also try throwing high value treats away from the door and then slip out while your dog is distracted by them.

Sorry for the essay; hope some of this is helpful!