Dr. Stephanie Everidge

Your pet’s eye or eyes appear red in color due to increased inflammation. This inflammation can be on the eyelids themselves leading to the red appearance or even due to the blood vessels becoming enlarged on the whites of the eyes known as the sclera.  The blood vessels can enlarge or engorge with blood due to either something occurring on the outer portions of the eye or something internally in the eye.


There are many different causes of red eyes in dogs and can be as simple as allergies or more serious such as glaucoma or increase in pressure in the eye.  Other potential causes could be an infection inside the eye, an ulcer on the outer portion of the eye that could be due to a trauma event, low tear production, or an infection either inside the eye or outside the eye.  There are cases of disease elsewhere in the body that can lead to inflammation of the eye.


Several tests that can be completed by your veterinarian to try to diagnosis the issue with the eye.  The first step involves looking at the eyes with a specialized ophthalmoscope in both the light as well as in the dark to look at the back of the eye at the nerves and vessels.  The veterinarian will check the responses of the pupils as well as the response of the eyelids to the light.  This will ensure that the nerves to the eye are working properly.  The next step with this  is to look at the inner portions of the eye for evidence of infection/cells in the eye chambers as well as to look at the lens.

More specialized testing can involve taking the tear production of the eyes to ensure there is enough lubrication of the eyes.  Another common test is called Fluorscein dye test. It will turn the outer portion of the eye called the cornea a green color to look for any signs of trauma or an ulcer on the eye.  Also, the veterinarian may take a pressure check of the eyes to ensure there are no signs of glaucoma.  Sometimes pets have to be referred to a veterinary ophthalmologist if there are concerns about glaucoma or other issues in the eyes.


Treatment for redness of the eye can range from special eye drops and oral anti-histamines that help with the inflammation if it is allergy related to even antibiotic eye drops if there is a cut on the eye.  To ensure there is not a serious issue involved, have your pet seen if their eyes are red.

Want to read more about pet allergies? Check out our post: Itchy and Scratchy: A Primer on Spring Pet Allergies!!