Encouragement is all over the place for adopting a dog, especially a rescued dog who needs a second chance. I am the proud owner of a rescued dog, and it warms my heart to see how wonderfully he has filled out, his shiny coat, and most of all, his obedient, loving, loyal personality.

Still, that took much time, skill, and effort. I have had the opposite experience myself two other shelter dogs, and seen too many mistakes to play Holly-go-lightly. This is a very serious undertaking, and not to be engaged by the unknowing.

The problem is that many shelter dogs offered for adoption have serious psychological or other bad dog behavior problems, and even medical problems, which the frequently scanty screening methods did not detect or report. The reality is that a lot of those dogs were abandoned because the owners could not handle them. Most people who bring these dogs into their homes have little to no knowledge of dog body language and the silent symptoms of trouble that should be discerned in the first encounter.

Many of these shelter dogs have been abandoned for one reason or another. Some were neglected, some unwanted, some were pups of accident litters … Others were abused in horrific ways and are still emotionally scarred even though their physical bodies are healed. You need to ascertain the emotional scars to know what you are getting into.

Well-intentioned people often say: "Oh, I will pick the black one over there," then sign the papers and take him straight home. It was all because of the way he looked, be it sad, needy, pleading, sweet, eager, playful, whatever. They did not see the symptoms behind that look.

A few days later, the black dog is back at the shelter because the adopter could not handle his problems. Sometimes, people keep the rescued dogs with these severe issues because they feel the animal has been through enough trauma already. "Maybe love will change him over time…"

To avoid the heartache of having to return a dog and/or the stress of several years spent dealing with a rescued dog's bad dog behavior, do your homework. Study the key signs in dog body language that reveal dog dominance, dog aggression, obsessive dog behavior, dog chewing, and other unwanted dog behaviors.

If you want a quiet dog, do not choose the one who is about to leap through the cage to say "hi" to you. Pick the one who sniffs you slightly and stands or sits with her ears slightly back. Wiggling is fine, too. A sweet little wiggle is just too cute!

Before you adopt a dog, insist on taking the one you are considering on a walk. Make sure you can see firsthand how this dog is going to handle everyday situations. Be sure the walk is proper. The dog needs to see you as a leader right away. Walk her behind you for at least 20 to 30 minutes. Be sure she is well exercised before you bring her home.

If the shelter staff protests, stand your ground and invite one of the employees to come with you. You have a right to see how the shelter dog responds to all types of situations and how the dog will surrender to your individual touch prior to commitment. If you cannot see the dog's behavior in the outside world, don't take it!

So adopt a rescued dog if you like. But if you are set on a certain breed or color, wait until you are absolutely sure this dog is the right one. Don't cave in to appearances. You want to avoid the heartache of bad dog behavior or dog psychological problems you are not equipped to handle. If you do not know how to read the subtle signals of dog body language, take a professional with you to evaluate the dog. A shelter dog can be a wonderful pet, just as my obedient Gatsby, but it all starts with choosing wisely.