For no reason that we can see our 3yr old hitch has decided that she wants to poo at 3.30am every morning. She has gone all night for as long as we have had her, even as a pup. I suppose we should be glad that she cries till we let her out but not ideal for us having broken sleep. Her motions are not loose and she us in good health. Any ideas to get her back to her normal routine would be gratefully recieved.

You could try altering her feeding time(s). Earlier to make her poo earlier, or later so she will last until the next morning.

My two year old male has been doing this since the mornings began to get light so early.  Sun starts shining birds are singing etc so the brain says "must be time to go out".  Add to this the muggy nightime temperatures during this heatwave and I think they just get restless.  Hopefully it will pass but Im not holding my breath until the mornings get lighter a little later.

She only has one meal a day, usually at 6.30pm, so I tried feeding her at 5 but it made no difference. The birds do start singing here at 3.30am but I would presume that they always have done this. It just seems that she can no longer go more than 4hrs. She has never been desperate for the toilet, we used to show her and she would go all day before she would do even a wee, as she liked to go on familiar ground.

So she poos 9 hours after her meal.
Try feeding her at lunch time so she can poo at her last toilet before bed. Make sure that she gets a good opportunity to poo, maybe by offering the garden and a little potter down the road.
But I think you'll find that she goes back to the old routine when it cools down and goes darker later.

> My two year old male has been doing this since the mornings began to get light so early.  Sun starts shining birds are singing etc so the brain says "must be time to go out".  Add to this the muggy nightime temperatures during this heatwave and I think they just get restless.  Hopefully it will pass but Im not holding my breath until the mornings get lighter a little later.

One of mine too.   He's driving me nuts as he sleeps in my room and he's up with the lark, big time just now - the birds noise being more obvious as the windows are open.

To the OP - I'd feed two smaller meals a day (as I always have, living with a breed prone to GDV).  Mine are fed breakfast at around 7 am, and the second by 4.30 pm - I'm trying to delay the second feed as it's so hot during the pm at the moment.   This means they will either empty (BM) before bed, or first thing next morning.    As I understand it, digestion in the dog normally takes around 4 hours.

Her toilet habits are very irratic. As I say she has been out at 3.30am goes back to sleep and will poop again on her walk around 8am. Each time only a small amount but not hard, so she is not constipated. Hopefully she will return to normal when the weather cools down and we don't have windows open. She is a Shetland Sheepdog and a real Diva, the big ones were not half the trouble. Will try feeding her at lunchtime and see if that helps. Good job we are pensioners so can have a siesta in the afternoon.

Does sound very much like mine.  He will poo small amount in the early hours and then again when I walk him at 7.30ish.  I am convinced its nothing to do with feeding as he doesnt have a regular time for his evening meal (his choice) sometimes he will want it at 5.30ish but another day wont want it till 8pm. I really think that with mine at least, its all down to the light mornings and the hot weather.