Not all dogs are potty trained as puppies, and those that are may develop inappropriate elimination issues later in life. Whether you've recently adopted an adult dog that isn't trained or your own dog requires a refresher course, you can potty train a dog of any age. Use positive reinforcement techniques and provide frequent trips outdoors to get your adult pooch consistently going potty when and where he's supposed to.
Establish a Routine
Establish a consistent routine for your dog that you follow every day. This includes when you take him out to go potty and when you feed him. The American Society for the Prevention of Cruelty to Animals recommends bringing your adult pooch outside a minimum of four times each day. To avoid accidents, bring your dog out first thing in the morning, an hour after meals, before you leave him alone and before bedtime. Choose a spot outdoors, about 10 square feet in size, that you bring Fido to, so that he learns this is the place he should eliminate.
Reward and Observe
Whenever your dog properly eliminates his designated potty area, give him plenty of praise and treats to positively reinforce this behavior. Between bathroom breaks, keep Fido on a leash indoors, attached to your wrist or belt, so that you can observe him for signs that he needs to eliminate. If you see him pacing, whining, circling or sniffing around, immediately head outside to the potty area. Give a command, like "Potty" to your pooch when you arrive at the potty spot; when he eliminates, reward him. Eventually, he'll learn to associate the command with the action of eliminating.
If you catch your pup in the act of eliminating indoors, simply interrupt him with a loud clap, gently grab his collar and quickly bring him outdoors to the potty area to finish. Once he finishes, praise and treat him. When you find accidents after the fact indoors, clean them with an enzymatic pet cleaner, found in pet supply stores, to eliminate the smell so it doesn't attract him back to the area. Don't punish your pooch during or after an accident, because it won't teach him anything and may actually encourage him to eliminate in hidden areas.
Potty training can take days or months, depending on your dog. If your previously potty-trained dog only recently started having accidents, a medical issue could be to blame. Visit the vet to rule out an illness before beginning potty training again. If you can't walk your pup during the day, have a dog walker come in and give him a chance to potty when you're not available, especially if he's an elderly dog that might not be able to control his bladder as well as a younger adult dog. In certain situations, you may consider training your dog to potty on pee-pads.