If your dog truly was house-trained and starts having accidents, there's an underlying cause.

Here are a few possible explanations and steps to take.

But First

Are you sure your dog was fully trained in the first place? Do you ever find yourself explaining away accidents with statements like, “She only peed on my shoes because she was upset with me.” Or, “He’s mad about fill-in-the-blank, so he pooped in the kitchen.” If you find yourself creating explanations for finding accidents in the house, you probably should refresh your dog’s house-training skills first. If none of those apply, and your rock-solid, never-has-accidents dog starts having accidents…

Timing

A common—but oddly often-overlooked explanation—is that your dog is left alone for too long. Sure, she might be able to hold it like a champ for your eight-hour workday, but if you head out to happy hour or a work dinner afterwards, she might not be able to make it. If your schedule is steady, it’s likely that your dog didn’t fully “empty” before you left home. Either way, try getting her a little bit of a longer walk in the morning before you go and coming home before after-work functions for a little quality (and bathroom) time.

Stress

Often, dog owners suspect their pet has an accident out of spite or some other emotional reason. That isn’t exactly true, though the root of the problem is usually simple: your dog is experiencing stress. Maybe you have a new boyfriend or you moved apartments. Maybe your neighbors are having their house repainted or you just had a baby. Whatever the cause, a dog experiencing stress can start having accidents. Try to identify the stressor and figure out a plan to mitigate it, or consider doggy daycare if it’s something that can’t be changed.

Diet

Have you changed your dog’s food? Is her nutrition whole, complete and balanced? If your dog is eating well, is she eating on a regular schedule? A routine can help prevent accidents because you can “set” your dog’s bathroom clock by figuring out when she needs to go after a meal, then adjust feeding times to fit.

Disease

A number of health issues can cause your dog to have issues. The most obvious, of course, is anything GI-related. But other problems like urinary tract infections, Cushing’s disease, kidney disease and more can cause your previously house-trained dog to have accidents.

Medication

Some medications might cause your dog to have to go more frequently. Hopefully your vet warned you of that potential, but do a quick web search for any medications your pet is on to see if that’s a potential explanation.

What NOT to Do

Never scold, correct or yell at your dog, and don't rub her nose in the accident. All that that accomplishes is scaring your dog, and if she’s not properly house-trained or is experiencing one of the problems mentioned above, it won’t keep her from having accidents. Instead, she’ll sneak off to find a place to hide her accidents.

What to Do

There are many possibilities for explaining accidents. The first and most important step is to call your vet. Schedule an appointment, and while you’re waiting for it to roll around, track your dog’s accidents. Is it a certain time of day? In a specific location in the house? Note anything that could be relevant so that your vet can help you figure it out—and, most importantly, implement a solution.