Short answer: call your vet first, then reset the routine. Dogs Trust says accidents in adult dogs are often due to a medical issue, a change in routine, stress, or scent marking.
Rule out health first
A vet check can rule out medical causes. Changes to watch for: peeing more often, larger or smaller amounts, being unable to hold it, or leaking. Common causes include urinary tract infections, bladder stones, and kidney disease. A change in poop that you cannot explain is worth a call too. These are symptoms, not a diagnosis, so book an appointment. For more on this, see Why Is My House-Trained Dog Peeing Inside.
If your dog is healthy: a fresh start
Set up a predictable toilet schedule for the next few weeks. Take your dog out after meals, after sleep, and after play or walks, and often through the day. Reward every time your dog pees or poops outside, right as they finish. If you reward too early, your dog may stop before finishing.
Clean well, stay calm
Use an enzymatic cleaner, often labeled pet odor remover, so the spot does not smell like a toilet. Do not scold your dog for accidents. Dogs Trust warns that making a fuss or telling a dog off can make the problem worse. Clean up calmly while your dog is busy elsewhere.
Think about why
New home, new schedule, or a stressful change? Rescue dogs may have no history of house training, or an old one that does not fit your home. Give your dog a small, predictable world while they settle. For marking, ask your vet about neutering, though some dogs still mark.
Get the right help
Sudden accidents in a dog who was house trained are a reason to call your vet. If your dog also seems anxious when alone, or accidents only happen when you are out, ask a qualified behavior professional.
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Frequently asked questions
What do I do first?
Call your vet. In adult dogs, accidents are often due to a medical issue, a change in routine, stress, or scent marking.
What changes should I watch for?
Peeing more often, larger or smaller amounts, being unable to hold it, or leaking. Mention all of it to your vet.
How do we reset the routine?
A predictable toilet schedule for a few weeks: out after meals, sleep and play, and reward every outdoor success.
What about cleaning?
Use an enzymatic cleaner so the spot does not smell like a toilet, and do not scold. Telling a dog off can make hiding worse.
