Best Answer: The pupil size limits the the amount of light that enters the eye. There are also day-time photoreceptors, the cones, which occur with three kinds of photo-sensitive pigments, for red, yellow-green, and blue.
Those âdevotedâ dogs lying on their mastersâ graves? Theyâre depressed. âMany dogs are simply depressed for their whole lives because theyâre deprived of the normal amount of attention, exercise, and stimulation they need from day one. These humans wonât know they have a problem and wonât want the dog any livelier as that wouldnât fit in with their lifestyle,â says Tamara.
Common Signs of Depression in Dogs . The signs of depression in dogs are actually similar to those experienced by people. Dogs have down days and bad moods just like people. When your pet seems particularly lethargic or appears to be moping around the house or yard, it's possible that she feels depressed. According to Bonnie Beaver, DVM, symptoms of canine depression typically include: