"I mostly see that people crop the ears of their Doberman dog. I asked many owners, but everyone told me different reasons."
If you asked this owner , I would give you only one reason: Our dogs all have had cropped ears, because.... Currently, in the US, the overwhelming percentage of breeders that I would consider buying a puppy from, send their pups home cropped, docked and with their dew claws removed. And while I actually prefer the look of a cropped Doberman, if and when reputable breeders start offering Dobe pups with natural ears, and if I end up with one, I would probably leave it that way. Tail and dew claws? Those, I would prefer "disappeared! LOL
John L
Portland OR