Based on current veterinary guidance — updated June 2026.
Your dog is squinting. There's a goopy discharge in the corner of one eye, and they keep pawing at it. Is it an infection, an allergy, or just a bad pollen day? Here's how to tell the difference — and exactly what to do (and not do) next.
The 7 Warning Signs of a Dog Eye Infection
According to the American Kennel Club and PetMD, these are the signs veterinarians look for:
- Discharge — cloudy, yellow, or greenish (more on color below)
- Redness — in the white of the eye or the inner eyelid
- Squinting or excessive blinking — a sign of pain or light sensitivity
- Swelling — around the eye or of the eyelid itself
- Pawing or rubbing — at the eye or face against furniture
- Excessive tearing — wet streaks or crusty, matted fur around the eye
- Keeping the eye closed — the strongest red flag of the seven
What the Discharge Color Tells You
| Discharge | What it usually means | Urgency |
|---|---|---|
| Clear and watery | Allergies, wind, mild irritation | Monitor 24h |
| Reddish-brown tear stains | Normal porphyrin staining (cosmetic) | Routine cleaning |
| White-gray mucus | Possible dry eye (KCS) | Vet appointment |
| Yellow or green | Likely bacterial infection | Vet within 24h |
| Any discharge + closed eye | Possible ulcer or foreign body | Vet immediately |
For a deeper breakdown of what each discharge color and crust means, see our guide to dog eye boogers and discharge.
Is It Really an Infection? The Common Look-Alikes
True bacterial infections are less common than owners think. VCA Animal Hospitals notes that conjunctivitis (the most common "eye infection" diagnosis) can be triggered by allergies, foreign bodies (grass seeds are notorious), dry eye, trauma, or anatomical issues like entropion — not just bacteria or viruses. If you're trying to tell allergies from a true infection, our guide on dog eye allergies vs. infection lays out the differences side by side. Environmental yeast can also colonize the skin folds around the eyes in dogs prone to yeast overgrowth; if your dog also has itchy paws or ears, read our guide on dog yeast infections and home remedies.
What You Can Safely Do at Home
- Wipe away discharge with a sterile saline solution and a clean cotton pad — one pad per eye, wiping from the inner corner outward.
- Trim long hair around the eyes (carefully, or have a groomer do it).
- Use a dog-specific eye cleaner for routine maintenance and tear stains — regular cleaning is one of the cheapest forms of prevention. See our ear & eye care collection and our guide on why regular cleaning prevents infections.
- Support eye health from the inside — once any active issue is cleared, some owners add daily plant-based eye & vision support drops to food alongside good hygiene to help with eye clarity and tear-stain control. These are a daily wellness supplement, not a treatment for an active infection — for that, see your vet.
- Prevent rubbing — an e-collar for a few hours beats a scratched cornea.
Never do this: human eye drops (Visine and similar are not safe for dogs), leftover antibiotic drops from a previous prescription, or anything containing steroids without a vet exam — steroids on an undiagnosed corneal ulcer can be catastrophic.
When to See the Vet — The 24-Hour Rule
Veterinary consensus is blunt on this point: eyes are unforgiving. UrgentVet and Small Door Veterinary recommend a vet visit if symptoms persist beyond 24 hours — untreated conjunctivitis can permanently damage the cornea. Go the same day if you see: the eye held shut, a visibly cloudy or blue cornea, blood, a bulging eye, or an object stuck in the eye.
How Vets Diagnose and Treat Eye Infections
Expect three quick, painless tests: fluorescein staining (detects ulcers), a Schirmer tear test (rules out dry eye), and tonometry (rules out glaucoma). Treatment depends on the cause — antibiotic drops for bacterial infections, antihistamines for allergies, lubricants for dry eye. Most simple infections clear within 5–7 days once treated correctly.
Prevention: The 2-Minute Weekly Habit
Most eye problems we see in breeds like Shih Tzus, Pugs, Frenchies, and Poodles are preventable with a simple weekly routine: check both eyes in good light, wipe the corners with a dog-safe cleanser, and keep facial hair trimmed. Our complete walkthrough: how to clean your dog's eyes safely.
FAQ
Can a dog eye infection heal on its own?
Mild irritation can resolve in 24 hours. True infections rarely do — and waiting risks corneal damage. Apply the 24-hour rule.
Is a dog eye infection contagious to other dogs or to me?
Some causes (certain bacteria and viruses) can spread between dogs. Transmission to humans is rare but wash your hands after handling the eye area.
How much does treatment cost?
A standard exam plus medicated drops typically runs $100–$250 — far less than treating a perforated ulcer, which can require surgery costing thousands.
This article is for informational purposes only and does not replace professional veterinary advice. If your dog shows signs of eye pain, contact your veterinarian.
Sources: AKC — Dog Eye Infections · PetMD — Conjunctivitis in Dogs · VCA Animal Hospitals — Conjunctivitis in Dogs · Small Door Veterinary — Pink Eye in Dogs · UrgentVet — Conjunctivitis in Dogs