I'm going to get a few splinters in my arse from this post, but here goes.
My DD1 was bitten, badly, on her leg when she was 4 years old, by a miniature poodle. This scared her, not just physically but emotionally. At the time we had two crossbreed dogs (staffy/JRT cross and a Doberman cross) they were the most docile, sweet, gentle dogs I have ever known. We had had the dogs for 8/9 years prior to having our DD's so our DD's had grown up with them from the moment we came home from the hospital.
DD1 was not at all scared of our two after this attack from a bloody poodle. However she developed PTSD regarding unknown dogs (Diagnosed by LA child therapist). She would suffer such bad panic attacks on just spotting a dog, even on a lead, while we were out that we became almost housebound.
After our two dogs had to be PTS within 16 mo of each other (they were old, 17 & 18, and both had cancer) DH and I obviously decided no more dogs due to DD1's pure, unadulterated fear of unknown dogs.
A few moths after loosing the dogs DD1 met a Doberman Pincsher who was so lovely, gentle and sweet with her that it was the first time in a long time that DH and I had seen her with an unknown dog and not suffer a panic attack. It didn't take DD1 long time to start asking for another dog, specifically a Doberman. After a lot of research, thinking time and a long search for a bred specific dog (DH and I always had cross breeds/heinz 57's prior to having the DD's).
Almost a year after losing our JRT/Staff cross we got our current dog, she is now 10mo and just as sweet, loving, gentle doberman as the one that DD1 met all those months ago. This crazy, excitable bundle of giant paws, floppy ears and lots of skin to grow into mended our DD1.