In the last 4 days my 16 month old bitch has for no apparent reason, started to wee in the house. She has done one poo indoors but all other poo's have been outside.  I can't think why she is doing this, we have had builders in the house for the last 6 weeks but up until now that has made no difference to her toilet habits.  My only thought is that maybe she is due to come into season, she has only had one season so I am not familiar with the timing of her seasons yet it has been 6 months since her last so it is possible, although there are not yet any other signs of this.  I have her 4 year old mum living with us as well and there has been no change in her toilet habits.

Has anyone experienced this before and maybe have an explanation.

A season is likely, but also disliking the rain and holding on too long, or perhaps you still have fireworks being set off as around here, just back from a walk where I had to keep telling the 2 1/2 year old that we were not being invaded.

I forgot to mention that these wees are full on emptying of the bladder not little scenting wees, I think that means it's less likely to be a urine infection, as from experience an infection usually makes a dog wee little and often.

Maybe a long shot but I'd take her to the vets and get her checked out.  I bumped into a friend of mine at the park today who told me he'd taken his labby to be checked for a similar problem.  His dog has been diagnosed with diabetes and is now on 2 injections per day to stabilise the condition.