Blepharitis in dogs is a common condition that leads to inflammation of the eyelids, causing discomfort and the risk of further complications. It is characterized by symptoms such as redness, swelling, itching, squinting, and discharge from the eye. Canine blepharitis can affect one or both eyes and is often caused by a variety of factors such as congenital abnormalities, infections, allergies, tumors, trauma, and other inflammatory disorders. Please continue reading to learn more about the causes, symptoms, and treatment options for dogs with blepharitis.
What is blepharitis?
Blepharitis refers to the inflammation of the eyelids, resulting in irritation and swelling of the tissues surrounding the eyelids, and is one of the most common causes of swollen eyes. It is also common in many dogs with skin disease and often leads to, or is associated with periocular dermatitis.
What are the causes of blepharitis in dogs?
Canine blepharitis can be caused by various factors. Inflammation may occur due to infection caused by bacteria, fungi, viruses, and parasites. It can also be a result of immune-mediated and allergic conditions, foreign bodies, or neoplasia. Sometimes, the cause remains unidentified (known as idiopathic).
Certain dog breeds may have a predisposition to specific underlying causes of blepharitis. However, for most cases of blepharitis, there is no breed predisposition.
The following are potential causes of diffuse blepharitis in dogs:
Infections: Bacteria or fungal infections can result in blepharitis and eyelid inflammation. Occasionally, the canine herpesvirus can cause blepharitis in dogs
Parasites: Parasites that can affect the eyelid include mites, fly bots, or larvae. The demodex mite is the most common skin mite to affect eyelids and surrounding skin. Additionally, bot fly larvae known as cuterebra can burrow into your dog's eyelids, leading to localized inflammation and drainage.
Immune-mediated conditions: Various immune-mediated diseases can result in blepharitis. The most common is atopic dermatitis. Atopic dermatitis is also known as environmental allergies and can result in blepharitis. Meibomitis, or inflammation of the meibomian gland in the eyelids is another example of an immune-mediated cause of blepharitis.
Trauma: Blepharitis in dogs can occur due to foreign bodies, bite wounds, or other types of trauma. This includes self-inflicted injuries. Damage to the eyelids from heat, chemicals, or cold can also lead to secondary blepharitis.
Neoplasia (cancer): Uncommonly, blepharitis can occur secondary to primary or secondary cancer of the eyelids.
In a study involving 100 dogs with blepharitis, the most commonly identified underlying causes were allergic skin disease, followed by infectious/parasitic disease, autoimmune disorders, and neoplasia.
The entire eyelid does not need to be affected to have blepharitis and this is called localized blepharitis. A common example of this is a chalazion which is a localized meibomian cyst that can occur on the eyelid, causing inflammation and swelling of only a portion of the eyelid.
What are the symptoms of blepharitis in dogs?
Recognizing the symptoms of eyelid inflammation is important for early diagnosis and effective treatment. The clinical signs your dog may exhibit often depend on whether the blepharitis is focal or diffuse, as well as the specific underlying cause.
Common symptoms include:
- Redness and swelling of the eyelids
- Constant itching or rubbing of the affected eye
- Squinting (called blepharospasm)
- Excessive tearing or discharge
- Crusting or debris along the eyelid margin
How is canine blepharitis diagnosed?
Blepharitis can be diagnosed by your veterinarian on a thorough physical examination. Your vet will assess your dog's overall health and look for any underlying conditions that may be contributing to the development of blepharitis.
All dogs with blepharitis should undergo a detailed dermatological examination. This is because the majority of causes are related to the dermatological system, such as allergies or allergic dermatitis, and various infections. Your vet may swab the area to look for evidence of an infection.
Your vet may also perform some ophthalmic tests such as the Schirmer tear test and fluorescein staining to assess the health of your dog's tear production and cornea, respectively.
How is blepharitis treated?
The treatment for canine blepharitis depends on the underlying cause. Your veterinarian will determine the most appropriate course of action after a thorough examination and various tests have been completed.
Once the underlying cause is identified, appropriate therapy is initiated. If your dog has allergies, treatment is focused on managing the allergic response and keeping symptoms under control.
In the case of bacterial blepharitis and secondary infections, a course of oral and topical antibiotics is required for a minimum of 3 weeks.
Additionally, anti-inflammatory medications can be prescribed for various types of blepharitis.
In cases of localized blepharitis that do not respond to medical treatment, surgery may be considered as an option to remove lesions.
For supportive care, it is recommended to carefully trim any matted hair from the eyelids and use lid wipes to gently remove debris. To help loosen crusted material, applying warm, wet compresses can be beneficial. Additionally, to prevent self-trauma, an Elizabeth collar can be used.
In conclusion, blepharitis is a common condition in dogs that can have various underlying causes. Early diagnosis and appropriate treatment are important for managing clinical signs and preventing complications. If you notice any symptoms of eyelid inflammation in your dog, consult with your veterinarian for proper evaluation and treatment options. With proper care, most cases of blepharitis can be successfully managed, leading to a happy and healthy pup.