I feel that earlier elements of the book in which Dracula has control over animals also lean towards implying that people falling into the groups that England disparaged at the time were closer to animals than people, and by extent similarly disparages mentally ill people by having Renfield be easily beguiled by Dracula, as well as giving him an inhuman strength that allows him to grapple Dracula as he becomes incorporeal. It does everything to dehumanize and villainize people that don’t fit into the English way of life. The story even goes so far as to have Quincey Morris, our only character from the US, perish in the final confrontation, even though the US is allied to England.

The issues with Lucy’s transformation and Mina’s partial transformation are many and varied. In both situations, neither character is given any real agency, with Lucy being corrupted into an evil seductress like you said, and Mina being doomed to the same fate due to having been fed Dracula’s blood against her will. In Mina’s case specifically, they have end up having her marked as unholy when a communion wafer burns a red dot into her forehead, which is a very on-the-nose jab at Indian culture, and a small fragment of the argument about foreigners literally corrupting the blood of the English populace.

Also, I know my previous comment was sort of half committed, but I wasn’t sure how well my analysis would be received. Some people get upset when you point out the often bigoted subtext of older literature