Abstract
Background: Keratitis is a common cause of eye diseases in horses, often resulting in complete loss of vision.
Aim: The purpose of the paper is to study the features of the clinical picture of primary and secondary keratitis in horses, depending on the form of the course of the disease.
Methods: The study was conducted in 2019 at 22 private horse breeding farms. The study involved 80 horses with keratitis, which were divided into two equal groups depending on the diagnosis of primary or secondary keratitis.
Results: The effectiveness of the therapies was compared 1, 3 and 6 months after the start of treatment. Following a 1-month therapy, only a minority of horses with primary keratitis had their eye functions fully restored, the number of horses with macula was 2 times higher (p ≤ 0.05), the number of horses with nebula was 7 times higher (p ≤ 0.001), and leukomas were reported in most of the cases (p ≤ 0.0001).
Conclusion: The effectiveness of the therapy for keratitis is directly related to the peculiarities of treatment and adherence to the regimen.

Key words: primary keratitis, secondary keratitis, tear production, leukoma, macula, nebula