This is such an interesting topic and I am in the "emotions" camp. Behavior is one of my favorite specialties (and I think the human animal bond is SO ESSENTIAL to our field/as doctors) and I've started offering behavior consults at my practice. Separation anxiety, vet-visit related anxiety......it goes on. With pets who are really bonded, when I euthanize a pet, I express concerns to my owners about not just their own grief but other pets in the household. We'll never know if an animal "feels" depression but I think they definitely experience grief just as much as they experience joy. And the whole scale in between.
I think the other big issue for a lot of people is that mental health within the human field is still so limited (and under-recognized). So when I talk about anxiety (or depression) with my clients, they might scoff at first (these same people might say depression isn't a thing).
But then I have others who completely agree that their dog is anxious and after trying some other options, consider medication much more readily.
To
@eeeee723 - I agree with
@that redhead . Talk to your vet. Or someone else behaviorally inclined (not everyone loves behavior as much as I do
)