Is a little blood in my cat’s stool always an emergency?

Not always, but it always deserves a same-week vet call rather than a wait-and-see approach. A thin streak of bright red blood on the outside of an otherwise normal, formed stool is often just minor irritation from constipation or straining, similar to the human version of the same thing. Blood mixed through loose or watery stool, dark tarry stool or blood alongside vomiting, lethargy or a swollen abdomen is a different situation and does need urgent care. The color and how it is mixed in matter more than the amount.

When to call a vet: Any blood accompanied by lethargy, vomiting or a distended belly is an emergency-vet situation, not a next-available-appointment one.