My Pet Center
Schedule Appointment

Conjunctivitis (Pink Eye) in Dogs

Conjunctivitis (Pink Eye) in Dogs | BetterVet

Pink eye is the inflammation of the membrane that lines the inside of the eyelid and the whites of the eye, the conjunctiva. The medical term for this condition is conjunctivitis. In a healthy eye, this membrane acts as a protective barrier against infectious agents and foreign material. It becomes less competent at performing this vital role when it becomes inflamed. So, what does it mean if your dog develops pink eye, and what should you do about it?

Pink Eye in Dogs: Symptoms

The signs of conjunctivitis in dogs can include the following:

  • Redness or a bloodshot appearance to the eye(s)
  • Tearing eyes
  • Discharge from one or both eyes (watery, cloudy, yellow, or green are all possible)
  • Squinting or excessive blinking
  • Swollen eyelids
  • Pawing at the face 

What Causes Pink Eye in Dogs?

Many people assume that pink eye is always the result of a bacterial infection, but did you know there are many different things that can result in your dog developing conjunctivitis? While not an exhaustive list, some potential causes include the following:


Bacterial, viral, and fungal infections are all possible causes of conjunctivitis. Examples include Canine Distemper Virus and the fungal disease Blastomycosis.

Immune System Disorders

The immune system is the body's defense against infections or foreign material. Sometimes the immune system can overreact to normal body components and lead to disease development. Several immune system disorders, including allergic conjunctivitis, plasma cell conjunctivitis, and pemphigus, can affect the eyes.

Tear Film Issues

Keratoconjunctivitis sicca (KCS), a tear film disease, is thought to be an immune-system disease leading to reduced tear production. Still, there are several other causes of decreased tear production (including some infections, some medications, and nerve injury. Some cases appear spontaneous). Reduced tear production leaves the eye surface vulnerable to irritation and subsequent inflammation.


Both cancerous and non-cancerous tumors can develop on, within, or around the eyes, which can cause inflammation.

Eyelid Disorders

Common problems of dogs' eyelids include entropion (turned-in eyelids) and ectropion (turned-out eyelids). Both can affect the surface of the eye, causing conjunctivitis. Additionally, eyelash disorders can also irritate the eye surface. You can also mention a condition known as distichia. This condition occurs when there is an extra eyelash that arises from an abnormal position on the eyelid margin and rubs against the surface of the eye (cornea). This constant irritation can cause conjunctivitis and permanent scarring to the cornea itself.

Tear Duct Disorders

Blockage of the tear duct can inflate the surrounding tissues, resulting in conjunctivitis.


Scratches to the eye's surface or foreign material (such as grass seeds) can cause conjunctivitis.


Glaucoma is the medical term for an increase in pressure in the eyeball. This condition makes the eyeball red and is extremely painful. It is a medical emergency, and without prompt treatment, it may result in blindness and eye loss.

How is Pink Eye Diagnosed?

An important aim when diagnosing conjunctivitis in dogs is to determine if it is a primary problem or if there is an underlying problem with the eye, the surrounding tissue, or even an underlying medical condition that predisposes your pup to conjunctivitis. 

Typically, your veterinarian will want to perform the following investigations:

  • A comprehensive visual examination of the eye, including inside the eyeball and the surrounding structures such as eyelids, tear ducts, and third eyelids.
  • Measurement of tear production
  • Staining the surface of the eye to check for damage
  • Measuring the pressure within the eyeball.

Additional testing may include running cultures for bacteria or fungi, allergy testing, blood tests, imaging studies, or even looking at the cells from the eye's surface under a microscope to better understand the root cause. Your veterinarian will recommend a diagnostic approach tailored to your pet's individual needs.

How to Treat Pink Eye in Dogs?

If you think your dog has conjunctivitis, they should be seen by your local veterinarian as soon as possible, even if the signs are only mild. The reason for this is that without appropriate treatment, it is possible, without treatment, for your dog's eye(s) to be permanently damaged. This can result in loss of vision or even the need to remove the eyeball surgically.

The treatment of conjunctivitis in dogs will be dictated by the reason the eye is inflamed in the first place. Your veterinarian may recommend eye drops or oral medications depending on the nature of the problem. Surgery is sometimes indicated if severe damage to the eye surface is noted. Similarly, if your dog has a structural abnormality (such as entropion), it may require surgical correction. It is important to note that not every case of conjunctivitis in dogs involves treatment with antibiotics because the cause is not always a bacterial infection. Your veterinarian can advise you on the justification for their chosen treatment approach for your dog.


It can be tempting to take a wait-and-see approach when it comes to pink eye in dogs. Given the potentially severe consequences of doing this, it is always advisable to have your dog checked by your local veterinarian if you notice anything unusual with their eyes. Your veterinarian can guide you on which diagnostic tests and treatments are necessary based on your dog's presentation.

Frequently Asked Questions

How do you know if your dog has pink eye?

Signs of pink eye in dogs include redness of the eyeball, puffy eyelids, discharge or crustiness from the eye, squinting, and pawing at the eyes or face.

Will pink eye in dogs go away on their own?

Unfortunately, in most cases, conjunctivitis in dogs will require treatment. Delaying treatment can lead to severe problems for your dog's eyesight, so it is best to get them seen by your veterinarian right away.

Does my dog need to be seen by the vet for pink eye?

Trying to manage your dog's pink eye at home can be tempting, especially if the symptoms are mild. However, depending on the cause of conjunctivitis, the condition can rapidly progress, leading to permanent eye damage and vision loss without appropriate treatment. Therefore, it is always advisable to make an appointment with your veterinarian in cases of pink eye in dogs.

Need to talk to a vet?   
Schedule Appointment
Back to top