Скачать или смотреть High Quality Puppy Formula Recipe Used by Professional Breeders.

Reasons for tube feeding vary, commonly it's necessary due to an upper reparatory infection, or pneumonia due to inhaling fluids during the birthing process both are quite serious in the newborn puppy because they may not be able to nurse, and it requires intervention.
Recipe:
1/2Lb Beef liver
1ml liquid baby vitamins ex: Enfamil Poly.Vi.Sol(from the drugstore)
1C water
1C whole-fat yogurt
1Tbs canola oil or mayo
10oz evaporated goats milk (substitute: evaporated cows milk(regular not skim or low-fat variety)
2 raw egg yolks
1tsp Karo (corn)syrup

This is for informational purposes only. Refer to your breed and body weight for proper amount.
Great news I never had to use this, when I went to weigh the puppy to determine correct dosage I found him happily nursing and now he's gaining. It pays to be prepared in advance of a litter. Happy to have been able to show you.