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.
Depression: Not all dogs will act depressed when they are sick. Loss of appetite: Some dogs will miss a meal at times, and you should be aware if you have the type of dog that misses meals. Vomiting and diarrhea: If your dog is healthy, one simple episode of vomitingis not too much to worry about.