Mirtazapine worked better for my dog than Entyce. Two vets separately told me that it was okay for the dog to be on both but, of course, see what this dog’s vet recommends.
One vet prescribed CBD pills, then a water-based liquid (he didn’t want small dogs on the oil), for several months, but more for old-dog arthritis; other vet was not a believer in it. Think it helped – until it didn’t – with aches, but didn’t see an increase in appetite that could be attributed to it.
Other than that, rotisserie chicken (skin removed) was sometimes scarfed down.
Don’t know if you want to do this, but we were most successful getting our old boy to eat through hand-feeding, either morsels or, if the food was of a mousse or pate consistency (most popular with him late in life, even though no dental issues), from a fingertip or one of those rubbery spoons designed for toddlers (use the back of the spoon to pick up a bit of the food, then smear it into the mouth).
Once he had some food in him, he’d brighten up and sometimes eat on his own. We kept up with this because, other than the loss of appetite, he was his same self – same personality, attitude, desire to go for walks, engagement in life, a lap dog par excellence.
Like your dog, he’d never been a morning type; he never had a great appetite even with excellent lab work results, and advancing age exacerbated that.