Why is my dog scared of a cardboard box

Desensitization

Begin by exposing your dog to a very low level or small amount of whatever it is that's causing his fear. For example, if he is afraid of bicycles, start with a bicycle placed at a distance of 100 feet from your dog.

Reward him for calm, non-fearful behavior in the presence of the bicycle. Gradually move the bicycle closer to him. As long as your dog remains relaxed, reward him with treats and praise. If at any point he becomes anxious, move the bicycle further away and proceed at a slower pace.

When your dog can remain relaxed in the presence of a stationary bicycle, move the bicycle 100 feet away again, but have someone ride it slowly by him. Again, gradually increase the proximity of the slowly moving bicycle, rewarding your dog for remaining calm and relaxed. Repeat this procedure as many times as necessary, gradually increasing the speed of the moving bicycle.

This process may take several days, weeks or even months. You must proceed at a slow enough pace that your dog never becomes fearful during the desensitization process.

Counter Conditioning

Counter conditioning works best when used along with desensitization and involves pairing the fear stimulus with an activity or behavior incompatible with the fear behavior.

Using the desensitization technique example described previously, while your dog is exposed to the bicycle, ask him to perform some obedience exercises, such as "sit" and "down." Reward him for obeying and continue to have him obey commands as the bicycle is moved closer to him.