Keratoconjunctivitis associated with eosinophils in dogs: A retrospective study of 35 cases (2004–2009) | Keratoconjunctivitis associated with eosinophils in dogs: A retrospective study of 35 cases (2004–2009)

The objective of this study is to present the clinical and histopathologic features of dogs with keratoconjunctivitis selected based on eosinophils detected in corneal histopathology. Thirty-five cases were reviewed focusing on breed, history, ophthalmic lesions, results of cytology and intradermal allergy testing for 19 allergens, and response to treatment which included keratectomy, topical antibiotics, and corticosteroids in variable conjunction with cyclosporine. Results are: patients included 18 males and 17 females, 9months to 12years of age (mean 6.8years). Among the 34 pure bred dogs were seven Boxers, five French Bulldogs and four Labrador Retrievers. History was that of uni- or bilateral chronic or recurrent corneal ulcers or chronic keratitis. Lesions most commonly were located in the temporal cornea with vessels extending from the limbus centrally to the mid-periphery to form a dense meshwork of thin vessels with an associated superficial stromal infiltrate and a superficial ulcer and associated corneal edema. Conjunctival inflammation and follicular hyperplasia of the bulbar surface of the third eyelid were a consistent finding. Ocular surface cytology showed a predominance of neutrophils and lymphocytes and infrequently eosinophils. Intradermal allergy testing showed a positive reaction to injected aeroallergens in 23 of 26 tested dogs with house dust mite the most common positive allergen. Corneal histopathology showed a hyperplasic epithelium, a lacking basal membrane in the area of corneal defect, an epitheliostromal clivage, a hyalinized acellular zone on the superficial stroma, and corneal infiltrate with neutrophils, monocytes and variable eosinophils. Treatment was effective in all dogs with complete resolution of the ulcers; variable recurrence was successfully managed by topical corticosteroids. In conclusion, this study indicates that eosinophils may participate to the corneal infiltrate of dogs with keratitis associated or not with chronic or recurrent ulcer. Hypotheses include an allergy.