Pigmentary keratitis in dogs – a study on incidence in 83 corneas

Objective: To evaluate the incidence, etiology and progression of Pigmentary keratitis in dogs. Materialsand Methods: A total of 83 corneas from 55 dogs of different breeds, sex and age were selected for the study. Signalment, anamnesis, nature of discharge and duration of illness was collected from all the animals.The progression of pigmentation was assessed by dividing the cornea in to four quadrants. Pigmentation grading, extent of pigmentation and mean pigment density were calculated by dividing the cornea in to 24 sectors. Schirmer tear test (STT), fluorescein dye test (FDT), tonometry, and slitlamp biomicroscopy and Cornealimpression cytology were done. Results: Among the 55 animals, 51 dogs were Chinese Pug (92.7%) and the mean age was 33.13 ± 3.12 months. Among 55 animals, 28 were females (50.9%) and left cornea was affected in 44 animals (53.01%). The mean duration of the disease as noticed by the owner was 07.21 ± 0.65 months.Most of the owners were totally unaware about the condition of the eye. Among 83 corneas, 40 (35%) showed pigmentation in all the sectors. 29 animals (53%) wereaffected with keratoconjunctivitis sicca (KCS) followed by 13 animals (24%) affected with entropion. The mean value of random blood sugar was 107.84 ± 0.99 and the mean intraocular pressure in the animals under the study was 40.64 ± 2.38. The mean value of pigmentation grading,extent of pigmenta ion and mean pigment density was 32.59 ± 2.27, 15.67 ± 0.83 and 1.37 ± 0.07 respectively. The mean value of Schirmer tear test was 10.31 ± 0.58 andunder high power microscopy, Leishman’s stained corneal impression cytology revealed infiltration of neutrophils in all the slides. Conclusion: It was concludedthat Chinese pugs under the age of 3 years are mostly affected and females and left eye is mostly affected. All the animals with pigmentation is having KCS.