What is up with my dog?

ok my dog is a male cairn terrier that has been deed. he is about 8 years old. latley he has started urinating in the house when he never used to do that before, he gets the same amount of walks every day and i can't think of anything that has changed. he also chewed thorough a quilt which is something he hasd never done before. any suggestions to stop this behaviour would be greatly appreciated