walk vs walk with

I walked with her to the subway. -- You are both going to the subway and walked together.
I walked her to the subway. -- You escorted her to her destination, the subway.

Does the second imply that she's an animal? -- Not at all. It means you escorted her. Let me walk you to your car. I'll walk you to your door.

GG, If you want to talk to your boss but he's on his way to a meeting, do you 'walk with him' to use the walking time to talk with him even though your destination is different?

This is quite common nowadays. Ther 'person in charge' (boss) may want to talk with you further about something, but she has to go someplace. Rather than stop the conversation then and there, she may say, 'walk with me'.