Summarize:

You need to take your dog out to relieve itself at the same time each day. For example, you may take your dog out after you get up, at lunch, right after work, and in the evening before you get ready for bed. Dogs should be taken out 3 to 5 times a day. Smaller and younger dogs require more walks then larger breeds. However, since your dog has been abused, it may require more trips outside. Just make sure to keep the dog on a leash while outside of a fenced yard. It’s normal to come home to accidents, but there’s no point in punishing the dog for them. Once the dog has walked away from the accident, it won’t understand why you are upset with it. If you do yell or put the dog’s nose in it, you will only risk triggering the dog.  Clean up any messes quickly. Make sure to use an enzymatic cleaning agent (available at most pet stores) to remove the smell so that the dog does not return to the spot. Remember that you should never yell at or punish an abused dog. If you catch the dog in the middle of an accident, make a noise like “whoops” to get the dog’s attention. Then take the dog outside to finish.  Be careful when you do this, however, since you don't want to trigger the dog. Use a calm tone of voice and choose one non-threatening word to use every time it happens. Be aware that you may get urine or feces on you when you do this. When the dog successfully waits to go outside, give it a treat for waiting. You should also praise it with statements like, “Good dog” and “Awesome job, buddy.”
Follow a schedule. Avoid punishing the dog for accidents. Interrupt accidents you catch and take the dog outside. Reward the dog for not having accidents.