Initial Outcomes Following Treatment With Topical Corticosteroids or Topical Calcineurin Inhibitors in Cats With Eosinophilic Keratitis

Objective To evaluate treatment outcomes in cats with eosinophilic keratitis (EK). Animals Studied Twenty‐eight cats (32 eyes), median age 7.9 years (range 1.2–18.0), diagnosed with EK. Procedures Medical records of cats diagnosed with EK from 2014 to 2022 were included if clinical signs or cytology were consistent with EK, and cats were treated with a topical corticosteroid (CS) or a topical calcineurin inhibitor (CI). All cats were examined at least twice by a veterinary ophthalmologist. Clinical signs, medication type, and medication frequency were recorded. Results Seventeen of 28 cats (61%) were treated with CS, and 11/28 cats (39%) with CI. Median time to improvement in cats did not differ between CS, 19 days, and CI, 16 days (Mann–Whitney U = 61.5, p > 0.10). Disease was considered controlled at last follow‐up, median 91 days, more often with CS (15/17 cats; 88%) than CI (6/11 cats; 55%) (X 2 = 4.0, p < 0.05). Disease control was achieved with treatment once a day or less, more often in CS cats (12/15; 80%) than CI cats (2/6; 33%) (X 2 = 4.2, p < 0.05). There was a high prevalence of corneal ulcers (12/17 CS cats, 71%; 10/11 CI cats, 91%), all of which healed regardless of treatment. Acute bullous keratopathy developed in one CS cat and one CI cat. Conclusions Initial response to treatment for EK in cats is similar when treated with topical corticosteroids or topical calcineurin inhibitors. Topical corticosteroid treatment may be associated with better control and less frequent medication.