TL;DR: Yellow or green eye discharge in dogs typically indicates an immune response or infection and warrants a veterinary appointment, though it is usually only an emergency if accompanied by pain, cloudiness, or squinting.
What does yellow eye discharge in my dog mean?
Finding yellow discharge, or "goo," in the corner of your dog's eye is a common occurrence that typically indicates an immune response. While clear or slightly reddish-brown discharge is often normal "sleep" crust, yellow or green mucus suggests that white blood cells are active. This is frequently caused by bacterial conjunctivitis, allergies, or a foreign irritant like dust or pollen trapped under the eyelid.
How urgent is yellow eye discharge in my dog?
- Monitor the condition and book a routine appointment if your dog is acting normally, eating well, and the eye itself does not appear red or painful.
- Move up your timeline for a veterinary visit if the discharge is accompanied by heavy squinting or cloudiness of the eye.
- Seek prompt care if your dog is frantically pawing at its face, as this suggests significant discomfort.
How does providing a photo help triage my dog's condition?
- Providing a clear, high-resolution photo helps a vet capture the exact color, consistency, and volume of the discharge at its peak.
- A photo documents the state of the surrounding tissues, which can change rapidly throughout the day.
- Visuals allow professionals to quickly differentiate between a simple case of "dry eye" and more serious issues like a corneal ulcer, ensuring the right level of care.
Clinical Context (Merck Veterinary Manual)
In young dogs, mucopurulent discharge can be associated with inflammation and prolapse of the gland of the nictitating membrane (cherry eye). In the acute stage, a red glandular mass swells and protrudes, accompanied by mucopurulent discharge. Yellow corneal changes due to leukocyte infiltration indicates severe infection. Radiographs of the skull after injection of contrast material into the duct (dacryocystorhinography) may be necessary to establish the site and cause of chronic obstructions.
Chapter: Ophthalmology
Source: The Merck Veterinary Manual, 11th Edition (Page 491)