Hamster has fur loss and bleeding ear HELP

[Mary_wilson]

About a month ago I noticed one of my hamsters ears had dry blood coming out of it and was loosing fur around her ear. I googled it and initially thought it could be mites as I live on a farm and have cats so they tend to bring things in from outside. I bought some mite drops and applied them and initially I thought it was growing back but tonight (2 weeks after using the drops) I’ve noticed another bald path behind her other ear and the furs fallen out again with blood reappearing. She’s only 13 months so I don’t think it’s old age. Could it be stress? Ear infection? Or mites?