My senior dog started panting at night for no obvious reason — what's going on?

Nighttime panting and restlessness in an 11-year-old Golden warrants a vet visit. The differential includes Canine Cognitive Dysfunction (dog dementia — disrupted sleep-wake cycles are a key symptom), pain (arthritis pain often peaks at night when dogs are still and can't distract themselves), Cushing's disease (your borderline kidney values make me want to check cortisol), or cardiac changes. A new blood panel plus a CCD behavioral questionnaire would be my starting point. Senilife, Anipryl, or gabapentin (if pain is contributing) can help depending on the diagnosis.

My older rescue had similar symptoms and it turned out to be arthritis pain at night. We added a heated orthopedic bed and a low dose of gabapentin (vet-prescribed) and it stopped almost immediately. The joint pain is much worse when they're lying still for hours.