What is Chalazion?
A chalazion occurs when the meibomian glands (or tarsal glands) are clogged. The chalazion develops along the eyelid margin where the meibomian glands are located. Meibomian glands produce sebum (oil), which helps keep the surface of the eye lubricated. Sebum prevents the evaporation of the dog’s natural tear film. The tear film protects the eye from particles (dirt, dust) and it also helps to keep the eye moist. When the opening of the meibomian gland (duct) gets clogged, the oil builds up in the gland and causes inflammation. This swelling in the gland is a chalazion.
A chalazion is not a hordeolum (stye). A stye also appears on the edge of the eyelid but it is caused by an infection, not by a clogged gland. The bacterium that is usually associated with hordeolums is staphylococcus aureus. Unlike a hordeolum, chalazia are non-infectious and are not usually painful. A chalazion is more common in older dogs.
A chalazion in dogs is a lump or nodule swelling on the inside edge of the lower or upper eyelid. The plural form for a chalazion is chalazia. A chalazion is also referred to as a meibomian cyst.
Symptoms of Chalazion in Dogs
Symptoms of a chalazion may include:
- Mass on the eyelid - Can be yellowish in color
- Blepharitis - Inflammation of the eyelid
- Itchiness caused by the lack of lubricant in the eye
- Redness on the eyelid
- Chalazia usually do not cause a pain response to touch
- Secondary bacterial infection
Causes of Chalazion in Dogs
A chalazion in dogs is caused when the meibomian glands are clogged and the oil they produce accumulates. This buildup of oil causes the painless bump to develop. The meibomian glands can get clogged due to:
- Dirt or sand
- Local injury
- Neoplasia - Abnormal growth of tissue
- Changes in the consistency of the sebum secretion
Diagnosis of Chalazion in Dogs
The ophthalmologist will want to know what symptoms you have observed in your dog and when they started. He will then perform an eye exam on the patient. He may recommend performing a Schirmer tear test, slit light exam and an intraocular pressure test. These diagnostic tests will help determine if there are any additional problems and/or abnormalities with the patient’s eye. The slit light exam may require your dog to be sedated. The veterinarian specialist will be able to visually identify the chalazion. He may suggest a complete blood count to rule out a secondary bacterial infection.
Treatment of Chalazion in Dogs
Treatment of a chalazion in dogs may include oral and topical antibiotics. The doctor may also prescribe a topical ointment with neomycin and corticosteroids. The veterinarian may also recommend soaking a washcloth in warm water and applying it on the eye with the chalazion, several times a day.
If the chalazion does not go away on its own and/or it continues to grow, the veterinarian may recommend surgery. A large chalazion can be uncomfortable for the dog and it can also scratch the cornea. Prior to surgery the patient will need to have a complete blood count (CBC), serum chemistry test and a urinalysis to make sure the dog can safely undergo a surgical procedure.
The surgical removal of chalazia may be performed by cryosurgery (cryotherapy), which uses liquid nitrogen to eliminate abnormal tissue growth. The prefix “cryo” means freezing. A dog undergoing this procedure usually does not have to have general anesthesia. The procedure may be done with the patient being given a sedative. There are no sutures needed. Laser ablation may also be recommended to remove the chalazion. This procedure uses a CO2 laser and a curette. Laser surgery also does not require general anesthesia and may be performed with a sedative. Some doctors prefer surgically removing the chalazion using a scalpel. This procedure does require general anesthesia and your dog may require sutures.
Recovery of Chalazion in Dogs
Canines that have laser or cryosurgery are usually treated as an outpatient and will be allowed to go home shortly after the procedure. Patients that were administered general anesthesia may need to stay overnight. It will be necessary that the patient wears an Elizabethan collar to prevent him from scratching at his eyes.
Please be aware that after surgery your dog may have blood in his tears and the area may be swollen. The surgeon will provide you with post-operative instructions. Your dog may be prescribed analgesic, anti-inflammatory and antibiotic medications. It is very important to follow the surgeon’s instructions. Follow-up visits will be required to ensure your dog is healing properly. Semi-annual eye exam visits may also be recommended. The prognosis for most patients is very good, chalazia usually to not grow back.
