Black and red toe?

I got a new chinchilla about a month and a half ago. Soon after I noticed there was something wrong with her toe. It started to get worse and turn more black and her hind toe is starting to turn red. I don't know what to do or how to treat it. Can somebody help?

Most recent: http://ift.tt/2unenC1
More recent: http://ift.tt/2tpqxNL
Begining: http://ift.tt/2umWjYR