Third Eyelid In Bull Terriers


Time to read 5 min

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Bull Terriers are captivating and beloved companions, known for their distinctive appearance and spirited personalities. Beyond their unique traits, Bull Terriers also have one fascinating anatomical feature that is shared with many other animals—their third eyelid, also known as the haw or nictitating membrane. In this blog post, we will delve into the purpose, functions, common concerns, and visibility of the third eyelid in Bull Terriers. By the end of this journey, you will gain a comprehensive understanding of this intriguing aspect of Bull Terrier anatomy and its significance in maintaining their overall eye health. 

What's the Third Eyelid in Bull Terriers? 

The third eyelid, medically known as the nictitating membrane or haw, is an intriguing anatomical structure that can be found in various animals, including dogs, cats, birds, and reptiles. It is an essential component of the eye's anatomy and plays crucial roles in protecting and supporting visual health. In Bull Terriers, this translucent membrane is located in the inner corner of the eye, adjacent to the lower and upper eyelids. 

The third eyelid consists of a delicate, semi-transparent membrane that can move horizontally across the eye's surface. The third eyelid usually remains hidden when the eye is open and only becomes visible when it partially covers the eye, in contrast to the upper and lower eyelids, which are more noticeable. Its mobility and capacity to cover the eye provide additional protection and enhance the eye's general health. 

Functions of the Third Eyelid in Bull Terriers


The third eyelid acts as a shield, safeguarding the eye from potential injuries, irritants, and foreign objects. It aids in avoiding harm to the cornea, the clear front part of the eye. By covering the cornea partially or completely when needed, the third eyelid acts as a physical barrier, reducing the risk of trauma. 

Moisture and lubrication

The third eyelid contains specialized glands that secrete a watery fluid. This fluid helps to keep the eye moist and lubricated, preventing dryness and ensuring optimal visual function. Adequate moisture and lubrication are essential for keeping the cornea and other ocular parts healthy and intact. 

Tear distribution

Tears play a vital role in eye health by providing essential nutrients, oxygen, and immune factors to the surface of the eye. The third eyelid assists in distributing tears evenly across the eye's surface, promoting effective hydration and the removal of debris or foreign particles that may come into contact with the eye during daily activities. 

Additional immune protection

The third eyelid contains lymphoid tissue, which plays a role in the eye's immune defense. This tissue helps to detect and respond to potential pathogens or foreign substances that may enter the eye, contributing to the overall health and resilience of the ocular system. 

Is it common for Bull Terriers to have visible third eyelid? 

It is relatively common for Bull Terriers to have a visible third eyelid. However, the prominence of the third eyelid in Bull Terriers can vary among individual dogs, and some Bull Terriers may exhibit a more pronounced or noticeable third eyelid than others. 

As we previously mentioned, a dog's age, general eye shape, and heredity can all affect whether the third eyelid is visible. In some cases, certain health conditions or irritations may cause the third eyelid to become more apparent. It's crucial to remember that even within the same breed, there might be variations in the third eyelid's visibility. 

While some visibility of the third eyelid in Bull Terriers is normal, any significant changes or signs of discomfort should be addressed by a veterinary professional to ensure the ongoing health and well-being of your beloved pet. If the third eyelid of your Bull Terrier suddenly becomes more or less visible, or if it appears red, puffy, or irritating, you should take them to the vet. They can assess the situation and determine whether any underlying issues or conditions require attention and treatment. 

Concerns and Conditions Involving the Third Eyelid 

Cherry eye in Bull Terriers 

Cherry Eye is a condition in Bull Terriers characterized by the prolapse or protrusion of the gland of the third eyelid. This leads to the gland becoming visible as a red, swollen mass in the corner of the eye. While cherry eye is typically not painful, it is essential to seek veterinary attention promptly to prevent complications and discomfort. To properly position the gland and restore its normal function, surgical intervention may be required in some circumstances. 

Tumors and growths on the third eyelid 

Just like any other breed, Bull Terriers can develop tumors or growths on their third eyelid. These growths can range from benign masses to malignant tumors and may cause changes in the appearance or behavior of the third eyelid. Regular eye examinations and diligent monitoring of your Bull Terrier's eyes are crucial for early detection and intervention if any abnormal growths are detected. To identify the type of growth and create an effective treatment strategy, the veterinarian may advise a biopsy or additional diagnostic tests. 

Conjunctivitis and the third eyelid 

Conjunctivitis is inflammation of the conjunctiva, the mucous membrane covering the inner eyelids and the white eye (sclera). This inflammation can also affect the third eyelid in Bull Terriers, leading to redness, swelling, and excessive discharge. Numerous things, including allergies, infections, irritants, and underlying medical disorders, can result in conjunctivitis. It's crucial to seek veterinarian care if your Bull Terrier shows conjunctivitis symptoms in order to receive a proper diagnosis and the best course of therapy, which may include antibiotics, anti-inflammatory drugs, or medicated eye drops. 

Maintaining Your Bull Terrier's Eye Health 

Regular eye examinations allow for early detection of any eye-related issues, including those concerning the third eyelid. By catching potential problems early on, you can ensure better treatment outcomes and preserve your Bull Terrier's vision and comfort. To keep your Bull Terrier's eyes in optimal condition, it is crucial to schedule routine check-ups with a trusted veterinarian.

Proper eye hygiene plays a vital role in maintaining your Bull Terrier's eye health. Take a proactive approach by gently wiping away any discharge or debris from your Bull Terrier's eyes using a damp, clean cloth. This simple practice helps keep the eye area clean and reduces the risk of irritation or infection. It's important to avoid using harsh chemicals or irritants that may further aggravate the eye. Opt for gentle, pet-safe cleaning solutions when necessary and follow the guidance of your veterinarian. 

A well-balanced diet plays an essential role in supporting your Bull Terrier's overall eye health. Ensure their diet contains essential nutrients including omega-3 fatty acids and the vitamins A, C, and E. These nutrients contribute to eye health and can help prevent certain eye disorders. Consult your veterinarian to ensure that your Bull Terrier's nutritional demands are satisfied and to receive appropriate suggestions based on their age and individual health needs.  

Environmental factors can impact your Bull Terrier's eye health. Protect their eyes from potential hazards such as dust, pollen, chemicals, and excessive sunlight. When in outdoor environments, consider using dog-friendly protective eyewear to shield their eyes from harmful UV rays and debris. Additionally, providing a clean and dust-free living environment can help minimize potential irritants that could affect their eye health.

Final Thoughts 

The third eyelid is a remarkable anatomical feature present in Bull Terriers and various other animals. While it is not unique to Bull Terriers, understanding its purpose and functions contributes to our appreciation of these magnificent dogs. The prominence of the third eyelid can vary among individual dogs, influenced by genetics, eye shape, age, and certain health conditions. While some visibility of the third eyelid in Bull Terriers is normal, any significant changes or signs of discomfort should be addressed by a veterinary professional to ensure the ongoing health and well-being of your beloved pet.

By staying vigilant, seeking professional care when needed, and maintaining regular eye examinations, you can ensure the ongoing health and well-being of your Bull Terrier's remarkable eyes.