Conjunctivitis in Dogs

Reviewed by Amy Flowers, DVM on November 20, 2022

Conjunctivitis, also known as pinkeye or red eye, is as common in dogs as it is in humans. It’s an itchy inflammation of the tissue that coats the eye and the lining of the eyelids, called the conjunctiva.

Conjunctivitis can happen at any age, by itself or because of another eye problem.

While just one eye is typically affected, conjunctivitis can spread to both.


  • Redness
  • Puffy eyelids
  • Stringy discharge
  • Watery eyes
  • Pawing at their eyes
  • Squinting
  • Eyelids that stick together

At the first sign of these symptoms, it’s best to take your dog to the vet. They can tell what type of conjunctivitis you’re dealing with and how to treat it. Plus, your dog may have a more serious condition that could cause blindness if left untreated. It’s important that you don’t try to treat an undiagnosed eye condition yourself, as medication for one condition may aggravate another.

Common Types

Allergic Conjunctivitis

This allergic reaction is often seasonal and not contagious.


  • Dust mites
  • Pollen
  • Mold
  • Dander
  • Cosmetics and perfumes
  • Drugs


  • Cold compresses
  • Artificial tears
  • Nonsteroidal anti-inflammatory drugs
  • Antihistamines
  • Steroid eye drops

Viral Conjunctivitis

This is caused by a virus, spreads easily, and can take up to 3 weeks to get better.


  • Cold-like symptoms
  • Upper respiratory infection


  • Cold compresses
  • Artificial tears
  • Steroid eye drops

Bacterial Conjunctivitis

This type is also very contagious.


  • Streptococcus (strep)
  • Staphylococcus (staph infection)


  • Antibiotic eye drops or ointments

Show Sources


Purdue University College of Veterinary Medicine: “General Ophthalmic Conditions.”

CDC: “Conjunctivitis (Pink Eye).”

Medline Plus: “Allergic Conjunctivitis.”

K9 Wellbeing: “Dog Conjunctivitis.”

Johns Hopkins Medicine: “Allergic Conjunctivitis.”

American Optometric Association: “Conjunctivitis.”

International Guide Dog Federation: “Conjunctivitis (Pink Eye).”

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