behavior of my dog

Question
i adopted a dog and now he growls at us when we try to train on him, why

Answer
A poorly trained dog can embarrass its owner and offend other people--or even make them feel threatened. To raise a well-behaved dog, enroll him or her in an obedience class at a young age. Here are some pointers on how to handle common dog problems. Many of these instructions encourage the use of a shake can, a soda can filled with dry beans, coins or pebbles that you rattle sharply when a dog misbehaves.

Begging   Natural instinct; improper socialization; boredom; desire for your attention   Feed dog on regular schedule with no snacks between meals.      
     Never feed dog from dinner table.      
     Ignore dog while he's begging, or say "no" firmly.      
Biting   Natural instinct; improper socialization; puppy is teething; dog feels threatened; dog is injured; dog has been abused; dog is in heat   If puppy bites or nips, say "no" firmly and use shake can.      
     Provide chew toys for teething puppy.      
     If child teases dog, teach child to treat dog kindly. Do not leave child unattended with dog.      
     Put muzzle on dog that is injured and in pain to prevent biting.      
     If dog is over 10 months old, have dog trainer or vet evaluate her to determine whether it's safe to keep her.      
Chasing cars   Natural hunting instinct; dog is protecting territory; dog dislikes cars; dog wants to follow owner   Keep dog in secured yard where street is not accessible.      
     On walks, keep dog on leash. When he chases car, yank firmly on leash as it becomes taut and say "no."      
     Lavish praise on dog when he resists chasing cars.      
     Exercise dog regularly to reduce pent-up energy.      
Chewing   Natural teething process in puppies; boredom; separation anxiety; undernourishment; lack of exercise; thunderstorms   Provide plenty of chew toys as alternate chewing outlet, especially for puppies. Vary chew toys for older dogs.      
     Spray bitter apple (available at pet stores) on items dog likes to chew. Home remedies include hot pepper sauce, vinegar and hot mustard, as well as alum mixed with water.      
     Say "no" firmly and use shake can if you catch dog in act.      
     Exercise dog daily to relieve excess energy and anxiety.      
     Consult veterinarian if diet is problem.      
     Don't leave dog alone during thunderstorms.      
Digging through trash can   Hunger; boredom; attracted to odor   Store trash can in area inaccessible to dog, or use can with sealed lid      
     Spray bitter apple (available at pet stores) on trash can. Home remedies include hot pepper sauce, vinegar and hot mustard, as well as alum mixed with water.      
     Or place shake cans on top of trash can to startle snooping dog and to alert you if you are in hearing range.      
Digging up lawn   Natural sheltering instinct; desire to escape yard; boredom; separation anxiety; moles or rabbits; desire to cool off in hot weather   Discourage it early on; it's tough habit to break, especially in terriers      
     Provide doggy toys to entertain dog in your absence.      
     Provide kiddie pool if dog is digging hole to cool off in hot weather.      
     Exercise dog daily to burn off excess energy and anxiety.      
     Confine dog to area of yard where digging is acceptable if you can't stop her.      
Eating stools   Undernourishment; stress; boredom; poor hygienic conditions   Clean up stool as soon as dog has eliminated it.      
     Feed dog special food (available through vets) that makes feces undesirable.      
     Exercise and play with dog daily to relieve stress and boredom.      
     Keep dog on leash during walks. Yank at leash and say "no" firmly if he tries to eat stools.      
     Consult veterinarian if you suspect malnourishment.      
Excessive barking   Separation anxiety; boredom; fear; frustration; territorial aggression; hunger or thirst; thunderstorms   Treat underlying problem (see "Separation anxiety," next page.)      
     Exercise and play with dog daily to reduce excess anxiety and energy.      
     Train dog to know boundaries of yard and narrow area she feels territorial about.      
     Do not leave dog alone during thunderstorms.      
Fighting with other dogs   Natural territorial instinct; instinct to dominate pack; improper socialization   Enroll dog in obedience courses.      
     Keep dog on leash during walk. Yank leash and say "no" firmly if he growls at another dog.      
     Never try to break up dog fight with your hands. Hose dogs off, throw jacket on them or try to distract them with loud noise.      
Jumping on people   Improper socialization; dog is eager to greet person with a kiss   Consistently discourage at early age with firm "no."      
     Ignore dog and avoid eye contact when she jumps on you to discourage such behavior.      
     Tell dog to "sit" and reward her with affection and treats when she obeys.      
     Exercise dog daily to reduce excess energy.    

REGARDS
PATT