What happens if a dog goes without food for a day?

For a small puppy, going without food for a day can cause low blood sugar, shock, lethargy, and a drop in body temperature, and in severe cases may even be fatal. Puppies store very little energy and are physically weak, so they cannot endure long periods without food; if you cannot feed the puppy yourself, consider temporarily boarding it at a pet shop.

For a larger adult dog, skipping a day of food usually has little effect, but it can still lead to abdominal pain, lethargy, and a short temper. Resume feeding in small, frequent meals, and consider giving some pet probiotics to support digestive health.