Blue Cross vet examines dog's eye

Conjunctivitis in dogs

Conjunctivitis is an inflammation of the ‘conjunctiva’ of the eye. This is a mucous membrane that acts as a barrier to infection and foreign objects by lining the eyelid and covering the eyeball. When it is infected and inflamed it is known as conjunctivitis, or ‘pink eye’.

You will need to get your dog to the vet as soon as possible if you think they have conjunctivitis.

What are the symptoms of conjunctivitis in dogs?

The symptoms of conjunctivitis may include:

  • dog's eye weeping
  • eye infection - clear or green discharge from the eye
  • the whites of the eyes are often red, and the surrounding eye area swollen
  • pawing at the affected eye
  • squinting and blinking more than normal

These symptoms can also be present in other eye conditions - your vet will be able to identify the cause.

Conjunctivitis often starts in one eye and spreads to the other through contamination. But, if an allergy (a common cause) or virus is the cause of the infection, both eyes can be affected from the start.


If you think that your dog has conjunctivitis, even if symptoms are mild, consult your vet as soon as possible. If the condition is not treated quickly, it can cause permanent damage.

How do dogs get conjunctivitis?

There are a number of things that can cause conjunctivitis and your vet will need to investigate to establish which is to blame. Potential causes can include:

  • foreign bodies such as a grass seed or grit
  • an allergy
  • an injury
  • bites in the eye area
  • dry eye (caused by a lack of tears)
  • eye diseases, such as glaucoma
  • a bacterial infection (normally causes green or yellow discharge)
  • a viral infection, such as canine herpes or canine distemper 
  • parasites, such as eye worm

Dog conjunctivitis treatment

During an initial examination, your vet will give your dog a full eye exam to look for the cause. This will determine the treatment needed for your pet.

Treatment can include:

  • eye drops for dogs
  • antihistamines or steroids
  • surgery (in more serious cases)

Foreign object treatment

Your pet will usually need sedation to remove a foreign object from the eye.

Surgery may also be needed for a blocked tear duct. Your vet will also give either eye drops for dogs, antibiotics or both after their surgery.

If you're worried about giving your dog their eye drops, we have some great advice on how to do this.

Allergy treatment

If an allergy is the likely cause of your dog’s eye irritation, your vet may prescribe antihistamines or steroids. This should help the inflammation clear up in a few days.

Bacterial infection treatment

If your vet thinks a bacterial infection is the cause then they will usually give you eye drops containing antibiotics to treat your dog. If a more serious underlying cause is suspected, further tests may be done.

During the recovery period, a buster collar may be needed to prevent your dog from scratching at their eyes and causing any further irritation.

More on giving your dog eye drops.

Will my dog fully recover from conjunctivitis?

Dogs normally make a full recovery but, in rare cases, they can be left with sight problems or scars on the eye. Or, depending on the cause, they may need to stay on treatment permanently. Early treatment gives your dog the very best chance of avoiding these complications.

If your dog suffers with allergies, conjunctivitis is likely to flare up from time to time.

Can you catch conjunctivitis from a dog?

This is extremely unlikely, but it's important to get your dog to the vet right away.

— Page last updated 22/03/2024