I have a 2 and 1/2 year old cocker spaniel. He was well trained when he first got home, when he was about 2 months old. He learned to "go" in a newspaper that we have for him in a corner of the apartment. Lately he´s been having problems with this. He still goes on the newspaper, but whenever he feels like it, he´s pooping or peeing everywhere, on the floor, on the carpet, even on my bed. I don't know what to do!! I live in an apartment so I can't just let him out whenever he wants to. What can I do??

Claud, your dog's urinating and defecating on your bed is a clear signal from him that he believes he is in charge, or feels he can challenge your leadership. You need to brush up on your leadership with him. Labman has some wonderful information regarding that and I am sure he will post it when he sees your question. In the meantime, even though it is a link he uses in his responses, it is the same one that I have used for a while and you can read it while you wait for labman to respond with more information. Establishing and Keeping Alpha Position, Letting your dog know you are the boss

The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at Raising Your Dog with the Monks of New Skete For more on being top dog, see Establishing and Keeping Alpha Position, Letting your dog know you are the boss