The dog does not know it is Ekadashi
Dogs are obligate opportunists. They eat what is placed in front of them, and their digestive system has no mechanism to flag that sabudana khichdi or singhara atta roti is nutritionally mismatched for their biology. A dog's gut is designed to process animal protein efficiently, the small intestine of a domestic dog (Canis lupus familiaris) is proportionally shorter than a human's relative to body length, which means food transits faster and relies heavily on dense, bioavailable protein to extract adequate nutrition. When that protein disappears from a meal and is replaced with starchy fasting foods, the gut does not adapt overnight. It simply under-delivers.