The snot-like blood at the end of the cat's poop may be caused by the cat's gastrointestinal discomfort caused by the recent change of food. It may also be caused by parasites or feline distemper. It is best to take it to the hospital for examination. If it is due to a food change, it is best to add new food in small amounts and multiple times to allow the cat to adapt slowly. Give the cat more water at ordinary times, occasionally feed some probiotics to help the cat regulate its gastrointestinal condition, and perform deworming regularly.