TL;DR: Green eye discharge indicates a likely infection that requires veterinary attention within 24 hours to prevent potential permanent eye damage or vision loss.
What does green discharge from my dog's eye mean?
Green pus, or mucopurulent discharge, is typically a sign that your dog's immune system is fighting off an infection. Unlike clear tearing, which might be caused by allergies or simple irritation, thick green or yellow fluid is a collection of white blood cells and debris. Common causes include:
- Bacterial conjunctivitis
- Foreign bodies trapped under the eyelid
- Corneal ulcers that have become infected
Is green eye discharge in dogs considered a veterinary emergency?
The urgency level for green eye discharge is classified as Medium. While it is rarely a life-threatening emergency in the immediate sense, eye conditions can deteriorate very quickly. Seek veterinary care within 24 hours if you notice the following:
- Squinting or keeping the eye closed
- Pawing or rubbing at the eye
- The eye surface looks cloudy or opaque
Delaying treatment can lead to permanent scarring or even loss of the eye.
How does taking a photo of my dog's eye help with veterinary triage?
Providing your veterinarian or triage assistant with a clear, well-lit photo of the eye is incredibly beneficial. A photo helps professional staff prioritize your dog's appointment by capturing:
- The exact color and volume of the discharge
- The degree of inflammation in the surrounding tissues before the area is cleaned
- The overall severity of the irritation
Clinical Context (Merck Veterinary Manual)
In dogs, mucopurulent ocular discharge (green pus) can be associated with several conditions. Prolapse of the gland of the nictitating membrane ("cherry eye"), common in young dogs, presents with a mucopurulent discharge. Dacryocystorhinography, involving skull radiographs after contrast injection into the nasolacrimal duct, may be necessary to identify the site, cause, and prognosis of chronic obstructions of the tear drainage system. Treatment involves maintaining duct patency and instilling topical antibiotic solutions. Less frequently, imperforate lacrimal puncta may cause epiphora in young dogs. Swelling behind the last molar may also cause discharge and requires drainage, warm compresses, and topical lubricants.
Chapter: Ophthalmology
Source: The Merck Veterinary Manual, 11th Edition (Page 491)