I thought that this would work in a pinch for our canine friends:
1/3 Boiled rice.
1/3 Vegetables (I’ve found green beans to work well.
1/3 Meat or eggs. Easy to but away extra powdered eggs of SHTF.
Liver, fish oil, bone meal and un-cooked bones should be added.
Alfalfa pellets and sprouts when you can find them. Fozen Blueberries...chopped or pureed...2-3 tablespoons (1 teaspoon for a chihuahua) at least twice per week.
Access to the great outdoors for the other stuff.
Cod Liver oil, meat, and bone meal are almost a complete diet if they can roam the woods.