Thanks for all the replies. I wouldn't have waited till the 21st if it persisted. Luckily it only lasted 24 hours and he is eating again and was always drinking. I think I spoiled him on the moist puppy food, although he does eat the dry Science Diet for puppies <1 year for small or toy puppies. I prefer he eat the dry food which he does pick at as I see it going down.
Thanks again all.
