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What are the Signs of Pink Eye in Dogs?

Susana Bradford
January 12, 2024
6 minutes
Updated By
Expert Reviewed By:
August 29, 2023
6 minutes
Updated By
The most common signs of pink eye in dogs are irritation, fluid from the eyes, bloodshot eyeballs, and swollen eyelids. Some dogs...

Pink eye is a well-known ailment in humans, but what many people don’t know is that this condition is also a common problem for dogs. In dogs, it can irritate the eyes and lead to severe damage if left untreated. So, knowing what pink eye is, its causes, signs, and treatment can help you notice it and take action in time.

How Do I Know if My Dog Has Pink Eye?

If your dog has pink eye, you may notice redness, swelling, and discharge from one or both eyes. Other signs include excessive blinking or squinting, and rubbing or scratching the affected eye. If you suspect your dog has pink eye, it's important to consult with your veterinarian for proper diagnosis and treatment.

What is Pink Eye in Dogs?

Pink eye in dogs is also known as canine pink eye or dog conjunctivitis. It occurs when the conjunctiva, the part of the eye that lines the eyelids and connects to the eyeball, becomes irritated and inflamed. 

Some of the typical causes of pink eye in dogs include irritation by foreign material, such as pollen or grass, or infection from a virus, bacteria, or fungus. 

Some signs that a dog may be afflicted with this condition include redness and swelling around the eye, increased fluid discharge, and a change in behavior.

Conjunctivitis can occur in one eye or both. If the cause is an infection, it will start from one eye and spread to the other.

pink eye in dogs

What are the Types of Conjunctivitis in Dogs?

Dogs can develop three types of conjunctivitis.

Allergic Conjunctivitis

Dogs are allergic to various allergens. Allergic conjunctivitis is caused by allergens such as pollen, food, shampoo, mold, mites, and others. It can happen to dogs at any age but is more prevalent among dogs predisposed to hypersensitivity to substances. They are usually not contagious.

Viral Conjunctivitis

Viral conjunctivitis develops in a dog when the dog comes into contact with a virus that triggers inflammation of the eye membranes. It can be spread easily and fast, and it usually takes up to 3 weeks for the dog to recover. Examples of conjunctivitis-causing viruses include the canine distemper virus and canine herpesvirus.

Bacterial Conjunctivitis

While not common among dogs, bacterial conjunctivitis is caused by bacteria around the eye. The bacterial infection may be caused by an underlying condition like dry eye and corneal ulceration. The bacteria responsible for bacterial conjunctivitis include Staphylococcus, which can spread easily and quickly.

What Causes Pink Eye in Dogs?

Conjunctivitis can occur on its own, but it is often a symptom of some other health complication. The most common causes are bacterial and viral infections, followed by allergens in the environment. Other causes include:

  • Tumors of the eye and eyelid
  • Foreign substances such as smoke, dirt, and debris
  • Immune-mediated diseases
  • Dry eye
  • Obstructed tear duct
  • Trauma to the eye
  • Glaucoma
  • Parasites (not common)
  • Uveitis 
  • Eyelid or eyelashes defects like entropion and distichia, respectively

So how does a dog owner know their dog has pink eye?

What are the Symptoms of Pink Eye in Dogs?

Since dogs cannot say when they are feeling ill or distressed, owners should look for the symptoms of pink eye. It may show one or multiple signs, but in the end, your veterinarian should offer the final diagnosis.

Bloodshot Eyeballs and Swollen Eyelids

Dogs with pink eye typically develop physical symptoms such as a pinkish color to the eye and fluid discharging from the affected area. The eyeball may appear to be bloodshot, and the eyelid may become swollen, even to the point where the dog cannot open its eye. 

Pink eye also produces an increase in fluids, ranging from an increase in tears to pus-filled discharge, depending upon the severity of the infection. This discharge may be yellowish or greenish in color.

Behavioral Changes

Dogs suffering from pink eye may also exhibit behavioral changes that will indicate to their owners that their dogs are ill. Dogs with pink eye can become sensitive to light, so they may avoid going outside into the bright sunlight. Also, dogs may become more lethargic, sleeping most of the time when they may have previously been active. 

Pink eye in dogs can be very irritating and itchy to the sufferers, so dogs may often rub their eyes on their paws, the carpet, or the ground. If a dog rubs its eye excessively, then the owner should consider putting a space collar on the dog so it cannot further irritate the area.


Anxiety and some pain might occur when dogs are dealing with pink eye or other eye-related issues. As we mentioned above, the area around the eye can get irritated, bloodshot, or even swollen. As a result, if you notice your pet is in more pain or feeling discomfort, it could help to give them something that helps calm them down until the underlying condition of their eye problem has been appropriately dealt with.

Our favorite products for anxiety are natural remedies like:

Our Top Pick - Canna-Pet CBD Capsules (choose based on dog size)

In summary, the symptoms of pink eye in dogs include:

  • Excessive blinking and squirting
  • Red eyeballs
  • Overly watery eyes
  • Excessive and unusual rubbing of the eyes using paws or along an item
  • Sticky eyelids that don’t want to separate
  • Unusual and increased discharge from the eye
  • Puffy eyelids‍

How Does the Veterinarian Diagnose Pink Eye in Dogs?

A qualified veterinarian is the best person to diagnose a dog with pink eye. They will conduct a thorough physical examination and other tests to get the root cause of the problem and evaluate the damage done before recommending treatment.

The examination will include the following:

  • Physical Examination: They’ll perform a detailed examination of your dog’s eyes, eyelids, and surrounding structures using an ophthalmic lens.
  • Tear Production Testing: Using Schirmer tear strips, they will check the amount of tears the dog produces in both eyes. The test is not invasive.
  • Corneal Stain Testing: It is also called Fluorescein stain testing and checks the cornea for damages like cuts and scrapes. The test is also non-invasive. A special light and yellow liquid are used to expose any damage.
  • Intraocular Pressure Testing: It is used to check if there is pressure on the dog’s eyes. It aids in screening for glaucoma and uveitis.

The vet can also conduct more tests, such as viral and allergy testing, if the situation needs it.

How to Treat Pink Eye in Dogs

Most dog owners can treat pink eye in dogs at home, but they should consult with their veterinarians first to ensure the infection is not severe. For home treatment, dog owners should lightly wipe the area with a warm washcloth to remove excess discharge and clear away any foreign material around the eye. 

If a foreign object appears stuck in the eye, you should not try to remove the object yourself but instead, seek assistance from a veterinarian. The vet will prescribe eye drops or ointments to reduce swelling and fight any infections. The dog should respond to the treatment and heal within a week or two, but if you do not observe any improvement after a few days, you should take your dog back to the vet.

The vet will ascertain the cause of the problem and offer the proper medication. They could  recommend

  • antibiotics for bacterial conjunctivitis
  • antioxidants for viral conjunctivitis
  • surgical procedures for eyelid and eyelash defects

If the problem is dry eye, the dog will use tear-inducing medication for the rest of its life. Lastly, if the cause is immune-mediated, the dog is given immunomodulatory medication.


The best person to diagnose a dog is a vet. As a dog owner, you might diagnose the wrong thing and offer medicine that will cause more damage to the dog without curing the problem at hand. Also, ensure that you only give the dog medication recommended by the vet, not something you learned or saw online.

Visit Pettable's blog for more information on pet care and other helpful resources. We also write ESA letters to help you get ESA certification if you have an emotional support dog.

Meet the author:
Susana Bradford

Susana is an avid animal lover and has been around animals her entire life, and has volunteered at several different animal shelters in Southern California. She has a loving family at home that consists of her husband, son, two dogs, and one cat. She enjoys trying new Italian recipes, playing piano, making pottery, and outdoor hiking with her family and dogs in her spare time.

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