I have a 4 year old golden retriever and he nearly always has a certain amount of diarrhoea. He gets walked at least once a day, and on each walk I will need about 5 poop bags, and by the end I just can't pick it up as it's too watery. About once a month, he gets it so bad he ends up pooping in the house overnight so there's a huge mess to clean up the next day. I always let him out just before we go to bed and first thing in the morning, so he's never indoors for too long and he has opportunity to go. I would be happy to let him out if he was desperate in the night but he never asks, he just goes! I feed him standard dog food, have stopped all treats as that does make him worse. I've varied the types of dog food but nothing makes a difference. I have asked a vet about it but they don't seem bothered or know the answer to it, other than to suggest changing his food which I already have tried. Are there any reasons for him being like this? He is a purebred retriever so maybe it's a pedigree problem?