The last few mornings I've been coming down to find that one of our two dogs (working cockers) have had an accident on the kitchen floor. But rather than be a typical poo that they may do during the day, its dry and bitty. Does anybody know what can cause that? Thanks (and apologies for the subject matter just before lunch).

Sounds like constipation, I would try changing diet a little first but if it doesn't help I a day or so a trip to the vet to get some help.

It does sound like constipation through to me it seems like a contradiction in terms - ie if my dog had an accident in the night I would associate with tummy troubles and the result would be soft not dry
Have you changed the diet or timing of meals recently?
What's their last meal/snack?
If this just started out of the blue, I think it would be worth checking it out with the vet.
Note sometimes vets prescribe lactulose for constipation. It's the same lactulose that is available OTC (and much cheaper!) for humans. My last vet was one of those who would even suggest the latter and advise on the dosage. But never tell the pharmacist it's for the dog - even on the vet's recommendation - as then they are not supposed to sell it to you.

Are you, by any chance, leaving their dinners for them to eat at their leisure?

It doesn't take long for dogs to develop new "habits" and they might've simply decided to leave some of their food for a late-night snack, rather than scoffing it all at meal-time, and that's causing them to need to go during the night.

If that's the case, give them until a certain time to eat their food and then pick the bowls up.
Within a couple of days they'll get the message and know they need to eat as much as they want within a certain time.

Thanks all. Their dinners are usually scoffed down by about 6pm...not a thing left. It happened again last night, a small pile of very dry poo compared to the humongosly sticky piles they've each just done on the evening walk.

You need to take him to a vet, sounds like some really bad constipation or blockage, the really sticky poo is making it past the obstacle I would imagine and then the dry is passing a bit too later on. But a vet is only one who can tell properly.