
Hi Diane,
I think maybe a trip to the vet would be my first port of call. Runny poos that don't firm up in a couple of days when action is taken need investigating. Also, at 17 months, puppy food of any kind is not really an appropriate diet - it will be too rich for him probably.
Keep him on the chicken and rice with no added treats, titbits etc until you can get a vet appointment.
Good luck, and perhaps think of joining the forum so you can let us all know how he's doing ;)
Regards, Teri