The best way to help the dog that is afraid of specific things, like strangers, other dogs or a vacuum cleaner use a technique know as desensitization. That means exposing the dog to things that frighten it. Example, the dog is afraid of the vacuum sound, try to vacuum when the dog is in the next room. Eventually you would work up to the dog being comfortable with the sound up close. Dogs do learn at their own pace.
Never push a dog over its threshold. Be sure you learn how to read the dog's body language. Dogs give subtle signals when they are afraid. Example, flattened ears and a tucked tail, but yawning, licking the lips, a tense, stiff body, scratching and sniffing the ground are also signs that a dog may be nervous. When you see these signs, back off to a distance that does not trigger the dog's reaction. In the event that a dog does react, leave the area as calmly as possible next time start at a greater distance.
When a dog does not spend much time around other dogs or people take the dog everywhere you can. Only do this if the dog level of stress is mild. Do not put the dog into crowds of people and don't allow strangers to approach it could make the dog uncomfortable. Take it slow and steady the dog will eventually get used to being around dogs and people.
When the dog is shy of people, allow the dog to approach the people in the dog's own time. When a person leans over it can be frightening to a dog. When the dog approaches a person, ask the person to pet the dog on the side of the dog's face. Do not stare or lean over the dog. The person can even turn their body to the side. This body language will make the dog more comfortable.
A professional trainer, can evaluate the dog's issues and pinpoint exactly what triggers the fear response. Fear issues are often at the root of these symptoms and should be taken seriously. Chronic stress can be very unhealthy for a dog and can even cause impairment of the immune system and eventually can turn into aggression issues if left untreated.
Professional Pet Sitting Services offered in the Upper to Mid-Pinellas County Area