Step 1: rule out a medical cause
If a reliably house-trained dog starts having accidents, assume a medical cause until a vet says otherwise. The usual suspects are a urinary tract infection, bladder stones, kidney disease, diabetes, Cushing's disease, and — in older spayed females — hormone-responsive incontinence. Signs that point medical: straining, more frequent small amounts, blood, licking at the genitals, accidents while asleep, or a sudden increase in thirst.
Note: a dog who cannot physically hold it is not being spiteful or forgetful. Punishment here is both useless and unfair.
Step 2: distinguish peeing from marking
A full bladder emptying is a large puddle, usually on a soft surface, often when the dog could not get outside. Marking is a small amount on a vertical surface or a new object, often repeated, and often triggered by a new person, pet, or piece of furniture. Marking is communication, not a bladder problem — and it responds to management and (in intact dogs) to neutering discussions with your vet, plus blocking access to the favorite spots.
Step 3: the plan that actually works
- Go back to a schedule. Out first thing, last thing, after every meal, after every nap, after every play session — and every 2–3 hours for an adult dog, more often for a puppy or a senior.
- Supervise or confine. If you cannot watch them, they are in a crate or a small puppy-proofed room. Freedom before reliability is how accidents become habits.
- Reward the outside toilet, every time. The moment they finish, treat and praise — outside, not when you get back in.
- Clean with an enzyme cleaner. Standard detergent does not remove the odour a dog can smell, and the scent of a previous accident invites the next one. Never clean with ammonia-based products.
- Never rub a nose in it and never shout after the fact. A dog cannot connect a past accident to a present telling-off; they learn only that toilets near humans are dangerous, which drives the behavior underground.
Why a trained dog suddenly starts again
The common causes, in rough order: a medical problem, a change in routine or household, a new pet or baby, reduced walks in bad weather, a move to a new house (the old house's rules do not transfer automatically), age-related incontinence, or anxiety. Work the list honestly — most regressions have an identifiable trigger.
Frequently asked questions
How do I stop my dog peeing in the house?
Rule out a medical cause first, then go back to a strict toilet schedule, supervise or confine when you cannot watch, reward every outdoor toilet, and clean old spots with an enzyme cleaner.
Why is my house-trained dog peeing inside all of a sudden?
Most often a urinary tract infection or another medical cause; after that, marking, a routine change, anxiety, or age-related incontinence. Sudden changes deserve a vet check.
How long can a dog hold their bladder?
Most healthy adult dogs manage 6–8 hours, but asking for that daily is unfair. Puppies roughly manage their age in months plus one hour; seniors and small breeds often need more frequent trips.
Should I rub my dog's nose in it?
No. It teaches nothing except that toileting near you is dangerous, which is why punished dogs often start hiding their accidents instead of stopping.