my dog poops on the couch

Question
I have a shuipoo, (small dog) he goes in the couch to do his business.
It is soft and smell awfull, I give him pedigree puppy hard food, I tried black pepper in the sofa to see if it turns him off from it but no such luck HELP ME!! my husband said the dog in on his wayout how do I get him to stop?
Is there any tupe of food I couldd give to him to help it smell better?
NEED HELP QUICK.

Answer
Sam, first of all,  check your dog food ingredients. If corn is one of the first 5 ingredients, then switch to something else. Corn goes right through a dog and is not good for them. Second, why do you let your dog on the couch? If he is going in the same place every time, then you need to clean it with half water and half vineger. It is the only thing that dogs can not smell through. If he is going to the same spot on the couch, chances are he is just smelling it there. Do you have a crate for the dog? How old is he? Does he go anywhere else in the house? Let me know so i can help further.
thanks
Nancy