If it helps, I once had campylobacter - got it from chicken from Sainsbury's - I'd opened the packet the day before and wrapped it in cling film (before cooking it thoroughly). I was so ill I went to the doctors to get a blood test (and stool sample
) which was then rushed to hospital (I'd recently been in Africa, so it could've been malaria!). It turned out to be c'bacta and I was sick for about a week. Normally they give antibiotics but mine had already cleared up. If it was that unpleasant for me I imagine it would be very nasty for a poor dog. I had awful stomach cramps and lost weight - need to watch out for dehydration.
Hope the pup gets better soon.