Cat using house as bathroom

Question
Hello there,

I have a 10 year old tabby female and recently she's been really using my house as her own personal bathroom.

I have a catbox for her, but it's almost like she can't be bothered to use it, she used to tell me when she needed to go out, but she hasn't done that in a long while.

I have considered putting the catbox in a location nearer to her, but my roomie has a dog and I know the dog will try to eat the droppings.

My roomie is quite protective of his dog and very annoyed by my cat, the last thing I want to do is get rid of my cat and this behaviour has me worried.

Is there a way to retrain her to use the catbox and keep it where I have (out of the dog's reach)?

Thank you for your help

Answer
If it were me, I'd get a new room mate.  The dog is probably scaring her and she is afraid to go to where her litter box is.  How far away is the litterbox anyway?  

You could confine your cat in a small room with her litterbox, food, water and bed, for a couple of days.  She will probably use the litter box there.  But, if you turn her loose in a house with a dog, and put her litter box way far away, it might not do any good to retrain her.  As far as the positioning of the cat box, you can use a covered one and turn it towards the wall, giving the cat about a foot to get in and out of it.  

Also, please don't let her out unless you are with her.  They can be in so much danger outdoors.  Good luck and write again if I can help.

Barb