Cat pooping outside the liter box

Question
my 9 year old female cat just started pooping outside her liter box about 3 months ago. She poops on the floor right next to her boxes. She has 2 liter boxes. She uses her boxes for urination 100% of the time and poops on the floor 100% of the time.  She has privacy from our 2 dogs that have been with her all her life and they are very good friends.  The boxes are cleaned daily and often immediately after use.  I have put newspapers where she poops and she will use them and try to hide her business under the papers.  She doesn't appear to have a medical problem but has not been to the vet. Is there a way to turn this back around again.  She is very social and friendly.  She does not seemed to be stressed for any reason.  And she is not left alone.  She always poops during the night time and never during the day.  please help me.  Thank you

Answer
Hi
well there are many reasons why a cat may start this behavior known as middening, however it is basically scent marking.

I have written a web page about the problem it also contains details of a process for retraining them to break the habit and to help them re build their confidence.

here is the web page

/cat-poo.html

best wishes Kate