I have had my dog for about 6 1/2 years. She has recently started using anyone and everyone's bed as a bathroom. There is a doggy door that she can use to go outside, but she never uses it for some reason. How can I get her to use the doggy door instead of a bed for the bathroom?

Has she had a vet check recently?
Sudden changes in behaviour are often caused by a medical problem. She may have a urinary tract infection or plain incontinence.

When does she do it? When you go out? Have you seen her actually squat down and pee or are there just 'surprises' for you to find?