Yes take her to the vet.By the way what does "scrungie thing" mean. I don't understand.It could be ringworm from what I understand. Fungus treated with anti-fungal cream, which is also contagious and can spread to humans.
It was a scrungie type of thing that girls put around their hair to make a ponytail
Like this?
Do you know where it came from or what she was doing before in was on her neck? Maybe how it got on her neck?
How could you not notice when something appeared around your dogs neck? and for 5 loving days? why wouldn't you take it off?