My 8 year old mix - ****zu/Pitbull had not been eating for approx 4 days. She is drinking fine and is energetic. She deficated 2 days ago - not solid and not liquid very dark. My 14 year old ****zu/poodle had the same and is now eating and drinking just fine. Would the 8 year olds lack of sooner recovery have anything to do with her breed?