Why does my cat have blood blisters in his ear?

Answer by  Sael (313)

The most likely reason is that your cat has been shaking its head (from irritation such as mites or an infection) and damaged the cartilage in the ears. When the cartilage is damaged, it bleeds, and the ear flaps get bubbles of blood in them.

Answer by  Skullwing (746)

The cat may be suffering from ear mites which live in the ear and feast on blood. Blood blisters indicate an allergy to the mites, black dirt-like residue also appears.