Episcleritis in dogs is an inflammatory condition of the episclera, which is the thin layer of tissue between the conjunctiva and sclera — the white part of the eye. It is characterized by localized or diffuse redness and swelling in the affected area, giving the eye an irritated or bloodshot appearance. Even so, episcleritis typically does not threaten vision and is often considered a benign condition. However, it can cause discomfort for the dog and may sometimes be a recurring issue.

Here’s what you should know about the symptoms, types, causes, and treatments for the condition in dogs.

Symptoms of episcleritis in dogs

Dogs suffering from episcleritis may exhibit a variety of symptoms, ranging from mild to severe. The most common sign is redness of the eye, particularly around the area where the white of the eye meets the colored part. This redness is due to inflammation and may be accompanied by swelling. Other symptoms can include:

• Excessive tearing or watery discharge from the eye
• Pawing or rubbing at the eyes
• Sensitivity to light
• Visible blood vessels in the whites of the eyes
• Squinting or blinking frequently
• Raised nodules or bumps in the eye (in the case of nodular episcleritis)
• Discomfort or pain around the eyes

Types of episcleritis in dogs

Episcleritis in dogs can be classified into two main types based on the appearance and distribution of inflammation. These are:

Diffuse episcleritis

Also known as simple episcleritis, this is the more common and less severe form of the condition. It typically manifests as a localized, non-infectious inflammation that may appear like a raised, red area on the white part of the eye. This type can affect one or both eyes and is often self-limiting, meaning it can resolve on its own without extensive treatment. Dogs with diffuse episcleritis generally maintain normal vision and experience few complications. Golden Retrievers and Cocker Spaniels are particularly susceptible to this form of episcleritis.

Nodular episcleritis

This type of episcleritis is marked by the presence of well-defined and elevated nodules or masses on the episclera. These nodules — which can appear pink or red — may be mistaken for tumors but are actually inflammatory lesions. They can either be singular or multiple and usually affect only one eye. Nodular episcleritis is sometimes referred to as nodular granulomatous episcleritis (NGE) due to the granulomatous nature of the nodules. This form is most commonly seen in Collies and can be recurrent.

Causes of episcleritis in dogs

While the exact cause of episcleritis can sometimes be difficult to pinpoint, there are several known factors and conditions that can contribute to its development.

• Immune-mediated response: One of the primary causes of episcleritis in dogs is an immune-mediated response. This occurs when the dog’s immune system mistakenly targets the tissues of the episclera, leading to inflammation. The reasons behind this immune misdirection are not always clear, but it can be associated with other systemic immune disorders.
• Infections: Certain bacterial, viral, or fungal infections can lead to episcleritis in dogs. These infections may either directly invade the tissues of the eye or stimulate an immune response that results in inflammation.
• Allergic reactions: Some dogs may develop episcleritis as part of an allergic reaction. Allergens such as pollen, dust, or even certain foods could potentially trigger an inflammatory response in the episclera.
• Trauma or injury: Physical trauma to the eye or surrounding areas can also cause episcleritis. This could be due to a direct injury — such as a scratch or blow to the eye — which leads to inflammation as part of the healing process.
• Underlying systemic diseases: Episcleritis may sometimes be a secondary condition associated with underlying systemic diseases, such as Lyme disease or systemic lupus erythematosus. These conditions can predispose dogs to episodes of eye inflammation.

Treatments for episcleritis in dogs

In order to treat episcleritis, you’ll first need to get an accurate diagnosis from a veterinarian to rule out other conditions — like conjunctivitis or uveitis — which can present with similar symptoms. Your vet will closely examine your dog’s eye with specialized instruments to assess the extent of the inflammation. They might also conduct additional tests, such as a Schirmer tear test to measure tear production and a fluorescein stain to check for corneal ulcers. In some cases, blood tests or a biopsy may be necessary to identify any underlying systemic issues contributing to the inflammation. Once a diagnosis is confirmed, your veterinarian will discuss treatment options with you to help manage your dog’s condition effectively.

Treatment for episcleritis in dogs typically involves the use of anti-inflammatory medications to reduce swelling and discomfort. Your vet might prescribe topical corticosteroids or non-steroidal anti-inflammatory drugs (NSAIDs). They will also provide specific instructions on how to apply these medications and how often they should be administered. Be sure to follow these directions closely to ensure your dog receives the full benefit of the treatment. If your dog’s episcleritis is associated with an underlying systemic disease, treating that primary condition can also help resolve the eye inflammation.

Keep in mind that regular follow-up visits to the vet are important for monitoring your dog’s response to treatment and making any necessary adjustments. You’ll also want to observe your dog’s symptoms at home and contact your vet right away if you notice any unusual changes. Moreover, keeping your dog’s environment free of irritants and maintaining good eye hygiene can support the healing process and help prevent recurrences.

What’s the difference between episcleritis and scleritis?

It’s worth noting that episcleritis is often confused with scleritis, but there are key differences between the two conditions. Scleritis involves a deeper and more severe inflammation affecting the sclera itself, whereas episcleritis is limited to the outer layer. Furthermore, scleritis tends to be more painful and can lead to serious complications, including vision loss, if not treated promptly. Episcleritis, on the other hand, is generally milder and less likely to cause long-term damage.