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Why are my dog's eyes red?

Like our own eyes, your dog's eyes can become red and irritated for a number of reasons. Today, our Westminster veterinarians discuss a few of the causes of red eyes in dogs and how they can be treated.

Your Dog's Eyes

Our dogs' eyes work a lot like ours. They are active organs that are constantly adjusting themselves, working to transmit what your pup sees to their brain. Their eyes differ from ours in that they have a third eyelid, called the nictitating membrane, that is located in the corner of their eye. 

As you have surely experienced with your own eyes, there are a whole host of things that may cause them to become irritated and noticeably red, from external irritants to excessive dryness and disease. Some dog breeds face a higher risk of developing red, irritated eyes as well as associated health issues.

Flat-faced breeds like Pugs, Bulldogs and Shih Tzus as well as breeds with long hair around their eyes like Sheepdogs, Maltese and Poodles can experience red eyes more often than other dogs. Older dogs are also more likely to develop red irritated eyes, especially if they have pre-existing conditions such as diabetes or high blood pressure. 

Common Causes of Red Eyes in Dogs

If your dog's eyes are red and uncomfortable looking it's a sign of irritation and inflammation, which can be the result of many different eye health issues. Listed below are some of the most common health conditions that can lead to red eyes in dogs.


Just like you may get watery eyes and a stuffed-up nose when allergy season rolls around, your dog can get red, weepy eyes and become uncomfortable from any number of allergies. 

These may be seasonal to pollen or the like, or they may be to your pup's food. If you notice that your pooch has red eyes and is itchy or sneezing more often without seasonal patterns, bring them into your vet for allergy testing. 

Eye Injury or Trauma

This cause of red, irritated eyes can range from quite mild to very serious. Your dog may have a hair or piece of grass stuck in their eye that is irritating surface tissues and causing them to become red and inflamed. 

Your pup may also have a scratch, cut or another more serious abrasion that is difficult to detect. If you think that your dog has had a serious physical injury to their eye that is causing one or both of their eyes to become red, bring them into your vet as soon as you can. 


This itchy inflammation of the eye is also called "pink eye" and is relatively common in people. It affects the tissues covering your dog's eyes and generally only affects one eye at a given time. 

This infection can be caused by environmental irritants, viruses or bacteria. Because you likely don't know the case of your pet's pink eye, make sure you bring them into the vet for advice on how best to treat their irritated eyes. 

Dry Eye Syndrome

Also called keratoconjunctivitis sicca or KCS, dry eyes in dogs are caused by a deficiency in the moist film of tears that generally covers a healthy eye. When this film is thinner, it allows your pup's eye to dry out and become inflamed. 

One of the most common causes of this condition is immune-mediated disease in dogs that causes their tear gland to stop functioning properly. Other underlying conditions like diabetes can also have an impact on your dog developing dry eyes. 

What To Do If Your Dog's Eyes Are Red

You should never start treatment of your dog's red and irritated eyes without first consulting a vet.

Since red eyes are a symptom of a whole host of eye-related health issues, a veterinary examination will be required to determine the root cause of your pup's discomfort. Any attempts to treat your dog's condition without knowing what it actually is that you're treating likely won't help and may even worsen their condition.

That being said, some common treatments for health issues in your dog's eyes generally include medicinal, antibacterial or anti-inflammatory eye drops or ointments. Your vet will be sure to walk you through the best way to administer these treatments for your dog's red eyes to make sure they are as comfortable and effective as possible. 

Other Serious Eye Conditions That Your Dog May Be Suffering From

In some cases, a dog's red eyes can be caused by more serious issues that require surgical treatment, such as:

  • Entropion (eyelids that curl in, irritating the eye)
  • Glaucoma (a very painful eye condition that requires immediate care)
  • Ectropion (eyelids roll outwards, giving a sad droopy eyed appearance)
  • Cherry eye (inflamed third eyelid)
  • Drainage issues, or tear duct blockage

If your dog has any of these issues it's important to see a vet as soon as possible so that your dog's eye discomfort can be resolved before more severe symptoms and complications arise.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

Are your dog's eyes red and irritated? Contact our Westminster vets at Wachusett Animal Hospital today to book an eye examination for your four-legged friend.

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