Behavior problems in cats and dogs manifest themselves in many ways: excessive barking, destructive chewing or scratching furniture, inappropriate urination, aggressiveness, digging, and spraying are just some of the ways animals act out. Nervousness, separation anxiety, fear of loud noises such as fireworks and thunderstorms, stress and general anxiety are common in many pets and can lead to unwanted behavior.

In this survey, some demographical information (such as pet breed, sex, age, nutrition status, and...), some behavioral problems (such as inappropriate elimination, aggression, fear and anxiety, problems in activity patterns), and some predisposing risk factors (such as diet and sleeping problems, moving to a new place, changing the owner and introducing new pet to family) in 90 dogs (32 males and 58 females) referred to the Small Animal Teaching Hospital of Faculty of Veterinary Medicine, University of Tehran from Jan. 2010 to Oct. 2011 were recorded by questionnaire.

Terrier dogs were the breed most referred to our Hospital of Faculty of Veterinary Medicine, University of Tehran. Sixty-four dogs had at least one of four behavioral problems.

Thirty-six dogs had fear and anxiety, 17 dogs with aggression, 8 dogs showed inappropriate elimination and 3 dogs had inappropriate elimination. All patients showed anxiety and fear in different levels, so it could be the root of most behavioral problems.

Anxiety was the most frequent behavioral problem. So education and general learning for dog owners seem to be big, necessary challenges to reducing animal behavior problems. Treatment significantly depends on owner cooperation.