If your dog treats the couch like an upholstered toilet, his problem is either medical, hormonal, or behavioral. Sometimes when it seems like a dog is wetting himself on the furniture, it has nothing to do with his bathroom habits and everything to do with his desire to be the dominant animal in your home. Making him stop is first a question of determining why he does it, then eliminating the motivation for the behavior or teaching him otherwise.
Tip 1: Monitor your dog's behavior to learn his furniture-related bathroom habits. When he eliminates, does he drain his entire bladder, or simply spray a stream of urine and move on? If it is the latter, your dog is likely marking his territory, which he is compelled to do by both his hormones and your behavior.
Tip 2: Spay or neuter your dog. This is a simple solution to a whole host of behavioral problems, not the least of which is urinating in improper areas, like your furniture.
Tip 3: If you are trying to keep your dog off of furniture when you're not home, it's best to keep your dog on the floor at ALL times. While it may be pleasant to have your pooch next to you when you're relaxing on the sofa, it also teaches him that he's allowed up there, which can lead to him going up when you aren't around and eliminating all over the microsuede.
Tip 4: Take your dog out for adequate walks and exercise every day. Without adequate opportunity to eliminate outside, your dog will look for other venues, like the recliner.
Tip 5: Give your dog an alternative place for indoor elimination, like a pee pad. This way, if he is going to have an accident inside, he can go to the pee pad and eliminate instead of doing so on the couch. Make a pee pad available at all times and show your dog where it is -- instincts often guide your dog to use it, but if you catch your dog eliminating elsewhere, quickly take him to the pad so that he sees where he should be doing it.
Tip 6: Take your dog to the vet if he continues to have accidents on the furniture. He may be dealing with incontinence-related health issues, like kidney or neurological problems.
Warning: Never punish a dog after the fact. If you catch your dog urinating on the furniture, scolding may be effective, but once the deed is done, he won't understand the reason for any punishment you administer.