TL;DR: Dried blood on a cat's ear flap is usually caused by minor surface trauma or scratching and is typically a low-urgency issue unless accompanied by swelling or behavioral changes.
What does it mean if I find dried blood on my cat's ear flap?
Finding dried blood on the ear flap, or pinna, usually appears as small dark crusts or reddish-brown scabs. This is often the result of minor trauma to the skin's surface, frequently caused by:
- Self-trauma from scratching due to allergies or ear mites
- Small nicks from outdoor encounters
- Reactions to insect bites
Is finding dried blood on my cat's ear an emergency?
The urgency level for dried blood on the ear flap is generally low if your cat is behaving normally. However, you should seek professional advice more quickly if you notice:
- The ear flap becoming thick and pillow-like, which may indicate an aural hematoma
- Signs of extreme pain or distress
- A loss of balance or coordination
How can a photo of my cat's ear help with a veterinary triage?
Taking a clear, high-resolution photo of the affected area is one of the most helpful things you can do for your vet. A photo allows a professional to evaluate:
- The exact pattern of the blood and the condition of the surrounding skin
- The presence of any discharge coming from the ear canal itself
- Whether the issue is a simple surface scratch or a symptom of a deeper infection
Clinical Context (Merck Veterinary Manual)
In cats, dried blood on the ear flap may be caused by trauma, leading to hematoma development with blood and serum filling the space between the skin and cartilage. Feline solar dermatitis, common in white cats or those with white pinnae chronically exposed to sun, initially presents as erythema and scaling on the ear tips, potentially progressing to crusting, exudation, ulceration, and ultimately squamous cell carcinoma. Aural contact dermatitis, affecting the concave aspect of the pinna, can result from topical ear medications (especially those containing aminoglycosides or propylene glycol) or transdermal ointments, manifesting as erythema, edema, and scaling.
Chapter: Dermatology
Source: The Merck Veterinary Manual, 11th Edition (Page 525)