Evaluation is warranted when following is sudden, intense, or paired with physical or nighttime changes. A dog who won’t leave your side and also has vomiting, diarrhea, coughing, limping, new accidents, or a big appetite shift should be seen promptly. For behavior, urgent flags include self-injury at doors or windows, nonstop vocalizing when alone, or panic that does not improve with routine.
A helpful way to decide is to ask: is the dog seeking closeness and then settling, or seeking closeness and staying activated? If the dog cannot settle even when the owner is present, that leans toward pain, cognitive change, or high anxiety. If the dog settles only when touching the owner, that can still be workable—but it deserves a plan rather than a shrug.