my 16 months old staffie bitch has for the past few months been wetting herself when she is asleep, she did it the other day whilst asleep in the front room, she did not even know she had done it. She has been spayed and i have heard this could be a side effect. Anyone have any advice or other suggestions as to what it could be. It is getting quite regular now about 3/4 times a week, but only at night not during the day.

Thanks