Behavior ChangesAny behavior changes that are not associated with a change in the household atmosphere, such as jealousy over a new pet or child may be an indication of an illness. Signs of behavioral changes may be:o Depressiono Anxietyo Fatigueo Sleepinesso Tremblingo Falling/StumblingIf your dog shows any of these signs, he/she needs to be kept under close watch for a few hours, or even a few days, until positive signs develop or he/she has returned to normal. Do not try to exercise the dog or put him/her in any situation that may cause stress. Most veterinarians will want for you to keep track of when the symptoms first appeared, whether they are getting better or worse, and also whether the symptoms are intermittent, continuous, or increasing in frequency.PainDogs that are in pain will likely indicate that they are suffering by giving you clues as to where the area of discomfort is. For instance, a dog that has abdominal pain will continually glance toward their belly, bite or lick the area, and will not want to leave his/her bed. The dog may stand hunched over, or take the ‘prayer position’ which is when a dog gets down on it’s forelegs with the hind legs still standing, because of the pain in her abdomen area.Dogs can not tell you that they are hurting or cry real tears but a dog may vocalize their pain in a different way. A dog that is hurt suddenly (such as being stepped on) will cry out or wimper in pain. This also happens when an external injury or internal injury (such as an organ) is touched. Whining or vocalization that is unprovoked may be caused from an internal injury as well. Some breeds of dogs (such as the American Pit Bull Terrier) have a higher pain threshold and need to be watched more closely for signs of pain. Breeds with a high pain tolerance are more likely to endure the pain without vocalization.Another clue to pain is a change in temperament. A dog that is in pain may show signs of aggression. Please take note of this before concluding that a dog has become vicious and let your veterinarian know so that the correct treatment can be administered. Also females in general (even humans!) have days when they are just in a bad mood for no obvious reason. Take note of days of times that these mood swings occur as well as any events that might have triggered them.