TL;DR: Black tarry stool in cats, known as melena, is a high-priority medical emergency indicating digested blood from the upper gastrointestinal tract. Contact a veterinarian immediately, as this often signals life-threatening internal bleeding or toxin ingestion.
What is black tarry stool in cats and what does it mean?
Black, tarry stool in cats is medically known as melena. Unlike bright red blood, which typically comes from the lower digestive tract, melena indicates that blood has been digested. This usually originates from the stomach or the upper small intestine. The digestive process changes the blood from red to a dark, sticky, and foul-smelling substance that often resembles motor oil or coffee grounds.
Is it a medical emergency if my cat has black tarry stool?
- The urgency level for black tarry stool is High, requiring immediate veterinary intervention.
- Melena is often a sign of significant internal bleeding, severe gastrointestinal ulceration, or ingestion of toxins like rat poison.
- Because cats are experts at masking pain, this visible sign may indicate a life-threatening situation.
- Immediate stabilization and diagnostic testing by a veterinarian are typically necessary to address the underlying cause.
How can taking a photo of the stool help with my cat's triage?
- Take a clear photo of the stool safely to help the triage team confirm the presence of melena versus dark food pigments.
- Use the photo to help the clinic prioritize your cat's care and prepare the necessary diagnostic tools before you arrive.
- Provide the medical staff with an accurate visual record of the stool's consistency and appearance.
Clinical Context (Merck Veterinary Manual)
In cats, black, tarry feces (melena) indicate hemorrhage in the stomach or upper part of the small intestine and can be associated with hemorrhagic, fibrinonecrotic enteritis of the small or large intestine.
Chapter: Gastroenterology, Infectious Disease
Source: The Merck Veterinary Manual, 11th Edition (Page 156)