Red Blood or Black, Tarry Stool in a Cat

Call your veterinary team if you see blood in your cat’s stool. Say whether it looks like a bright red streak or the whole stool is unusually black, sticky and tarry. Black, tarry stool can contain digested blood and warrants urgent advice. If your cat is weak, collapses, repeatedly vomits, or is passing a lot of blood, seek emergency care.

Describe the stool before you scoop it out

Use ordinary light and take a photo if you can do so without delaying the call. Tell the clinic whether the red material is streaked on the surface, mixed in, or in separate drops. For a dark stool, describe whether it was simply dark brown or looked sticky and tar-like. PDSA’s guide to blood in cat stool explains why either appearance should be discussed with a vet. A photo helps document the change, but color on its own doesn't locate the problem.

Add appetite, energy and recent changes

Report how much your cat has eaten, whether there is vomiting or straining, and any medication, food change or possible exposure. If you cannot tell which cat produced the stool, say so. Cornell’s feline parasite guide describes some conditions that can affect stool and why a veterinarian may ask for testing. Other causes need different evaluation, so avoid choosing a remedy based on color.

If the clinic requests a sample, ask what size, container and timing it wants. Our stool collection guide can help with that handoff. If another episode occurs before the visit, note the time and update the clinic if the amount of blood or the cat’s behavior changes.

Written by PARTNER Editorial Team for general education. Contact your veterinary team for advice about your pet’s individual health and feeding needs.