1.) Observe the expression. If a dog has a lively, alert, and happy expression, chances are good that he's a happy, intelligent dog. If he looks slightly cowed, doesn't want to make eye contact, and is reluctant to interact with you, he's probably timid and fearful.
2.) Watch the ears. Ears that lift (or prick up) at the slightest noise or motion tell you that you have a very alert and aware dog. That's a plus. Ears held low and drooping (this also applies to droopy-eared dogs, such as spaniels) are indicators of apprehension or fear and may be a signal that this is a frightened or timid dog.
3.) Look into the eyes. Just as with people, bright, wide-open eyes are indicative of intelligence, alertness, and curiosity. An eager expression in her eyes is a good sign that she's open or playful. If the dog avoids eye contact or slightly lowers her lids, that shows a fearful, timid disposition.
4.) Check the body language. An upright body posture, with head held high, ears pricked, and tail up and wagging, shows a positive, extroverted personality. A cowering body, with tail held between the legs, ears low and drooping, and eyes averted is a sign of a scared and possibly problematic dog.
5.) Listen to the voice. By nature, all dogs have a spectrum of sound: whine, whimper, yip, bark, and growl. Whining and whimpering indicate anxiety or fear. A yip indicates excitement, eagerness, or curiosity. A bark is generally for attention or to alert to danger, and a growl is a warning of aggression and dominance.
Bash Dibra, author of Your Dream Dog: A Guide to Choosing the Right Breed for You, is an internationally acclaimed animal behaviorist and trainer. His celebrity clients include Martin Scorsese, Jennifer Lopez, Sarah Jessica Parker, Mariah Carey, Kim Basinger, Alec Baldwin and Naomi Campbell, among others. He is a member of the Bronx County Kennel Club, as well as the Animal Behavior Society, the ASPCA and the Humane Society of New York, and is on the board of directors of New York SAVE, a nonprofit organization devoted to saving animals in veterinary emergency. Bash is a recipient of the New York State Humane Association Award and the New York City Veterinary Medical Association Unsung Hero Award. He resides in Riverdale, New York, with six dogs, four cats and a bird.
Reprinted from Your Dream Dog: A Guide to Choosing the Right Breed for You by Bash Dibra © 2003 Permission granted by New American Library