Hi Carol M, i have never had a “newfie” only a mix that the father was newfie and chow and her mother was a golden retriever. Maya was a pup the owners insisted i take 23 yrs ago when i rescued the adults from excaping their back yard because of kids leaving the gate open! and they wandered 2 miles without tags! it took 2 days to find the owners and they had thought someone had stolen them because the female was pregnant and a beauty! Maya was my only puppy since i was younger and she grew up to about 80 lbs and loved to eat! she passed at almost 16 yrs with never a food issue or diarrhea. i rotated mostly dry kibble with some canned dog food, some fresh meat and carrots (raw) and (steamed veggies) broccoli, string beans or butternut squash…yum!
sorry about that long dialogue above but i was reminiscing… i do think you need to check out the list of recommended foods for Large Breed Puppies in the forums and especially read the info hound dog mom provides about large breed puppies. i know that the 3 dogs that run my life now love castor and pollux ultramix! (check out the prices on chewy.com very reasonable.) i have been rotating or mixing both the grain free duck 38% protein and 17% fat with glucosomine and the grain free and poutry free salmon 30% protein, 15% fat and high in omega 3’s (i am a little concerned about the mercury level in the salmon which has been questioned on this site…) neither of these have ever caused diarrhea in my border collie/flat coat ret. mix 14 yrs 50 lbs or my husky/shepherd 12 yrs 80 lbs. My 80 lb lab has a very sensitive stomach and for some reason has not had a problem with these 2 kibbles in the 2-3 months she has eaten them, but as you know any changes in food always needs to be done slowly…7-10 days depending on the dog. you can add some pumpkin puree to help with initial introduction and slight problems. i assume your puppy has been checked out by a vet for any issues that would cause diarrhea …but most vets know nothing about good food recommendations!
.
