Redness, discharge, squinting, and pawing at an eye can all signal that something is wrong. People often call these signs an “eye infection,” but an injury, corneal ulcer, dry eye, eyelid problem, or foreign body can look similar. Some eye conditions can threaten vision quickly, so deciding when to seek an examination matters more than guessing which germ is involved.
Signs that your dog’s eye needs attention
- Redness: the white of the eye or tissue under the eyelid looks pink or inflamed.
- Discharge: more tears than usual, sticky mucus, or yellow-green material.
- Squinting or blinking: your dog partly closes the eye or keeps it shut.
- Pawing or rubbing: repeated attempts to rub the eye against a paw or furniture.
- Cloudiness: a blue, gray, or white change to the clear surface of the eye.
- Swelling: a puffy eyelid or swollen tissue around the eye.
- Behavior change: avoiding light, acting unusually quiet, or seeming unable to see normally.
Discharge color alone does not prove a bacterial infection. Some dogs have tearing from irritation or tear-duct problems; others have a corneal injury that needs immediate care.
When should you see an emergency veterinarian?
Arrange an urgent, same-day in-person examination for squinting, a closed or painful eye, new cloudiness, apparent vision loss, a bulging eye, visible trauma, or a chemical exposure. Severe injury, sudden vision loss, or a protruding eyeball is an emergency. Do not wait for a remote appointment to replace an eye examination.
If there is mild discharge without pain, call your regular veterinarian for advice and an appointment. If your dog starts squinting or the eye changes appearance, escalate promptly.
Common causes of red or runny eyes
Conjunctivitis is inflammation of the tissue lining the eyelids and part of the eyeball. It can be associated with infection, allergies, irritants, or other eye disease. Corneal ulcers are injuries to the clear surface of the eye and often cause pain and squinting. Dry eye can cause thick discharge and chronic irritation. Eyelashes, eyelid position, and trapped debris can also damage the surface.
The distinction matters: treatments that help one condition may make another worse. For background on diagnosis, read causes of red eyes in dogs and veterinary treatment options.
How veterinarians find the cause
The veterinarian may examine the eye with magnification, use a fluorescein dye stain to look for a corneal ulcer, measure tear production with a Schirmer tear test, and check the eyelids and surrounding structures. Additional tests depend on the findings. An online photo cannot reliably rule out an ulcer or measure eye pressure.
Safe steps while you arrange care
- Prevent rubbing; use a properly fitted protective collar if available.
- Gently wipe discharge from the surrounding fur with clean, damp gauze without pressing on the eyeball.
- Do not use human “redness relief” drops, leftover antibiotics, steroid eye drops, essential oils, or home remedies.
- Do not attempt to remove an object embedded in the eye.
- If a chemical splashed into the eye, seek emergency guidance immediately; prompt flushing with clean water or saline may be necessary while traveling to care.
Some steroid-containing eye medications can be dangerous when a corneal ulcer is present. Use only medication specifically prescribed for the current problem.
Frequently asked questions
Does yellow discharge mean my dog needs antibiotics?
Not necessarily. Discharge is a clue, not a diagnosis. An exam helps determine whether infection, dry eye, or another condition is responsible.
Can I wait until tomorrow if my dog is squinting?
Persistent squinting suggests pain and warrants a same-day assessment, particularly with cloudiness, trauma, or worsening redness.
Can a video visit diagnose a corneal ulcer?
No. An in-person eye examination and often a fluorescein stain are needed to evaluate the cornea properly.
Sources
- Merck Veterinary Manual: Disorders of the conjunctiva in dogs.
- Merck Veterinary Manual: Disorders of the cornea in dogs.
Educational information only; urgent eye problems require veterinary examination.
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.