How is possible to erase a phobia? Specially for dogs.

Erasing or extinguishing a phobia generally involves gradually desensitizing the person to the feared object by exposure to same. If you fear dogs, for instance, under controlled circumstances you would exposed to a dog(s), perhaps at first only by photos and discussion, then to contact with an actual dog, etc. This is only one example of course. In general terms it is a process of re-learning.

If you are in a position to obtain professional assistance there are many practitioners that deal with phobias. The process has a high success rate and is therefore rewarding to the phobic as well as the practitioner. If you have further questions in clarification please let us know.

I agree with DrBill -- gradual desensitization is probably the only way. Another technique is called "flooding" whereby the person who is afraid surrounds himself for a period with many dogs, say, in a small, closed room. The person will scream and cry and break out in hives, but the theory is that, after doing this probably more than once, he will be cured. (Research has shown that it doesn't work out this way, though.)

What seems to be the difficulty with dogs? Was this person perhaps once scared by a barking or big or too friendly dog?

(Both of my sons grew up scared of dogs, but love cats who don't move real fast and tend to stay in their own space. Dogs, or at least my sons' friends' dogs, moved fast, were yippy, and jumped all over anyone standing near them. My sons hated that, and so hated dogs -- and still do as adults. I would have been smart to adopt a dog from a shelter and add it to our family, but I too grew up without dogs because my parents didn't like dogs. So, in our family, the "no thanks to dogs" thing has come down through the generations.)