It is 5am and your dog is awake, bright, and standing by the bedroom door. By 5.20am you are downstairs with the kettle on, which is roughly when you realise this is now the routine.
Rule out the physical reasons first
Take this to your veterinary practice before you change anything, particularly if it arrived out of nowhere. Sudden behaviour change warrants a veterinary examination, and pain frequently presents as a change in behaviour rather than as obvious lameness.
Ask about 3 things by name: bladder, gut and joints. A dog who needs to empty their bladder at 5am is answering a physical question, not a training one.
Why 5am and not 3am
Early waking is different from night waking, because 5am is close enough to morning that it works. Your dog gets a person, a door, a garden and often breakfast. There is usually a cue in front of it too. First light through a thin curtain, birds, the heating clicking on, or a neighbour's car.
Change the cue tonight
Black out the window properly. A lined curtain, a blind, or a cover over one side of the crate.
Move the bed away from the window and the front of the house, into the dullest corner of the room.
Leave a fan or a radio on low all night, so the neighbour's car is not the loudest thing your dog hears.
Put the last real toilet trip at 10pm or later, on a leash, in the dark, with no play. Two minutes out and straight back in.
Then change the payoff
Get up on your clock, not on the whine. If you must go down, wait for a quiet 30 seconds first, so the noise is not what opens the door.
Make the first 10 minutes of the day dull. No greeting, no conversation, no game. The toilet trip happens and nothing else does.
Delay breakfast by 20 minutes and vary the time, so waking early stops predicting food.
Leave a chew or a stuffed food toy where your dog sleeps, so there is something to do at 5am that is not fetching you.
Do not tell your dog off at 5am. It is attention, arriving at speed, in a house that was quiet a second ago, which is close to the opposite of what you want.
Shift it, rather than fighting it
If your dog now wakes at 5am, aim for 5.15am this week and 5.30am the week after. Small moves hold better than a jump straight to 7am.
Look at daytime rest at the same time. Relaxation is trained as a behaviour in its own right, in short repeatable sets below the point where your dog gets restless. If the waking is about being alone rather than about the morning, that is different work. Gradual, sub-threshold departure practice is the core of that, and it belongs in daylight.
Safety note
Speak to your veterinary practice the same day if your dog is drinking much more than usual or seems disoriented. Do the same if they pant at night, or wake in apparent discomfort. Get help now if the waking comes with panic, howling, destruction at the door or self-injury. That needs a veterinary examination and a qualified behaviour professional.
Today's version, in one line: black out the window tonight, and give the first 10 minutes of tomorrow nothing but a leashed toilet trip.