[header] How to treat ear haematomas in cats [title] Recognize swelling or tenderness as a potential sign of ear haematoma. [step] A cat's pricked (upright) ear is usually normally no more than 3-4 inches (76-102 mm) thick, and is shaped like a gentle concave cone. A newly formed ear haematoma looks like a large blood blister. 
The ear flap may be tender to the touch, and feel warm or hot. Applying pressure to the ear flap can create the impression of fluid beneath your fingertips.