In the late 70's we got a dog that was Newfie/Shepherd/hound mix. He went 125 lbs. on s slim day. He ate and was fed everything. He ate corn flake and milk for breakfast most morning. He was fed coffee and donuts on my stepfathers construction sites. He ate lunch meat and all forms of table scraps (onions and garlic and all). On weekends he got bacon and eggs or pancakes and sausage with the family. He was feed what ever dog food that was popular back then (prob Purina dog chow).
He survived Parvo (our vets first case). It was a very severe case but, the vet pulled him through.
My mom bathed him with her human shampoo and conditioner (it really made him so soft).
With the exception of the puppy parvo he never had health issues. He never needed his teeth cleaned. He got soup bones often. He only went to the vet to get his rabies shot or if he had an injury.
By todays standards that dog was poorly fed. He should of had all sorts of health issues related to his supposed poor diet.
Sam lived to 17 years.