Blepharitis is inflammation of the eyelid margins which is nearly always accompanied by conjunctivitis. The most common causes are bacterial infections, demodectic mite infection, trauma, sun sensitivity, abscesses, and as extensions of or accompanying other eye diseases. Immune-mediated blepharitis is associated with pemphigus and uveodermatologic syndrome. Bacterial blepharitis can occur as part of "puppy strangles," in which multiple abscesses form on the head, including the eyelids. In the adult dog, Staphylococcus and Streptococcus species can cause superficial blepharitis.
Eyelid involvement is common in systemic canine leishmaniasis, and signs include alopecia, eyelid swelling, ulceration, and nodules.1 Fungal blepharitis results from skin infection with Tricophyton or Microsporum species. Yeasts such as Candida species have been associated with cases of ulcerative blepharitis in animals with skin atopy. The eyelids often become red and swollen, and the lid margins are usually encrusted with pus discharge. The dog will paw at the itchy eyelids and blink excessively. Sensitivity to light is also evident.
The diagnosis is made by the signs and physical examination. In some cases, biopsy of the lid lesions may be needed. Treatment is directed at removing the cause. Since most cases are either caused by, or accompanied by, bacterial infection, antibiotic eye ointments are often prescribed. Dogs usually respond well to a course of prednisolone over three weeks or cephalexin. Systemic antifungals can be useful for stubborn, chronic mycotic blepharitis infections. Demodectic blepharitis is usually self-healing in young dogs, but can be aided with systemic ivermectin or milbemycin.2 Immune-mediated form is treated with long-term systemic and topical corticosteroids. Stronger immunosuppressive drugs, such as cyclophosphamide, have also been used in chronic cases.2
- Heidi Featherstone, Elaine Holt. Small Animal Ophthalmology: What's Your Diagnosis
- Don A. Samuelson, Dennis E. Brooks. Small Animal Ophthalmology