Cat Hair

I am a transporter and I leave my cats home for 2-8 days at a time. They have adjusted to this and are just fine. However, I was gone about 10 days this past time and when I came home I found that one of my cats back is terribly matted! I don't understand what could have happened. I think it will brush out ok... I just don't get it. It seems to have a bit of dandruf look to it too. Can anyone give me any advise on what this is??