Dogs certainly experience bouts of sadness, but can they suffer from major / clinical depression?
The highly acclaimed veterinarian, Dr. Nicholas Dodman, believes they can not. Dr. Dodman differentiates between two types of depression:
Regardless of classification, the symptoms of dog depression include: sad mood, loss of interest or pleasure in activities that were once enjoyed, change in appetite or weight, difficulty sleeping or oversleeping, physical slowing or agitation, and energy loss.