TL;DR: Yellow discharge from a cat's ear indicates a painful bacterial or yeast infection that requires veterinary attention within 24 to 48 hours to prevent permanent hearing loss or neurological damage.
What does yellow discharge from my cat's ear mean?
Yellow pus or discharge draining from a cat's ear is a significant indicator of an underlying health issue, most commonly a bacterial or yeast infection. This fluid is a collection of white blood cells and debris produced by the body while fighting off an infection. It often occurs alongside inflammation of the ear canal (otitis externa) and can be triggered by ear mites, allergies, or foreign objects trapped in the ear.
Is yellow ear discharge an emergency for my cat?
- Urgency Level: Medium. While rarely an immediate life-threatening crisis, it is extremely painful and uncomfortable.
- Action Required: Schedule a veterinary appointment within 24 to 48 hours.
- Risks of Delay: Infection can travel deeper into the middle or inner ear.
- Potential Complications: Permanent hearing loss, ruptured eardrums, or neurological issues like a persistent head tilt.
How does a photo of my cat's ear help the triage team?
- Allows professionals to assess the volume, color, and consistency of the discharge.
- Identifies the degree of swelling or redness in the visible ear canal.
- Helps the clinic determine how quickly your cat needs to be seen.
- Enables the team to prepare necessary diagnostic tools before you arrive.
Clinical Context (Merck Veterinary Manual)
Unilateral chronic otic discharge, which can be purulent, mucoid, or hemorrhagic, accompanied by a necrotic odor, head shaking, and ear scratching, can be a sign of an ear canal tumor, especially in middle-aged to older cats. A dark exudate in the ear canal can signal the presence of Malassezia species or a parasitic infection, but can also be seen with a bacterial or mixed infection. Cytologic evaluation and culture of the exudate should be performed to identify the causative agent. The exudate should also be examined for ear mites (Otodectes cynotis) or Demodex mites, especially in young cats where feline demodicosis can present as pruritic otitis.
Chapter: Oncology, Otolaryngology, Neurology
Source: The Merck Veterinary Manual, 11th Edition (Page 534)