"Dogs" means plural. So the translation should be "Dia sangat takut pada beberapa anjing". Please someone help me to explain this.
The English expression is plural, but the plural is not actually relevant. It's not about some (specific) dogs, or several dogs as opposed to a single one. I think you don't use plural in Indonesian in such cases. (I'm really not an expert, though.)
"Dogs" in this sentence means generality. Maybe she is very afraid of golden retrievers, siberian huskies, pit bulls, german shepherds or other dogs. English uses plural for generalities, and I think Indonesian language uses singular (no need reduplication and "beberapa").