Emergency Dog & Cat Food Options – We recommend 1  8-oz bag for every 22 lbs of your pet’s body weight per 72-hour period.  For example, if your pet weighs 50 lbs, we recommend 3  8-oz bags of 5-year shelf life Mayday emergency food for one 72-hour period.  You know your pet, so if you have a very active animal you might want to add an extra bag of food.