TL;DR: Green eye mucus in cats usually indicates a bacterial infection or injury and requires a veterinary evaluation within 24 to 48 hours to prevent pain or permanent damage.
What does green mucus in my cat's eye mean?
Green mucus, also known as purulent discharge, is a common sign of a secondary bacterial infection. It occurs when the immune system sends white blood cells to fight off invaders like bacteria, viruses, or foreign bodies. In cats, this is frequently associated with Feline Upper Respiratory Infection (URI) or damage to the surface of the eye, such as a scratch or corneal ulcer.
How quickly does my cat need to see a vet for green eye discharge?
- The urgency level for green discharge is Medium, as eye issues can become painful and cause permanent damage very quickly.
- You should aim to have your cat evaluated by a veterinarian within 24 to 48 hours.
- Seek care as soon as possible if your cat is squinting, pawing at the eye, or if the eye surface looks cloudy.
How can a photo of my cat's eye help with the triage process?
- A high-quality image helps veterinary professionals distinguish between simple discharge and more serious structural changes, such as a protruding third eyelid or visible trauma to the cornea.
- Photos serve as a vital baseline to monitor whether the condition improves or worsens while you wait for your appointment.
Clinical Context (Merck Veterinary Manual)
In cats, mucopurulent ocular discharge, often indicative of secondary bacterial infection, can be a manifestation of several underlying conditions. Specifically, green mucus can be associated with conjunctivitis caused by feline herpesvirus-1, Chlamydia, or Mycoplasma. Diagnosis of the underlying cause requires differentiation from other infectious agents and is best confirmed using PCR for chlamydial DNA on conjunctival swabs. While broad-spectrum antibiotics are useful against secondary bacterial invaders, treatment is largely symptomatic and supportive.
Chapter: Infectious Disease, Ophthalmology
Source: The Merck Veterinary Manual, 11th Edition (Page 1482)