Comparative efficacy of subconjunctival palpebral and bulbar injection of gentamicin-dexamethasone combination in dairy calves with epiphora.
A prospective study was planned to compare the palpebral and bulbar subconjunctival injection of gentamicin-dexamethasone in dairy calves showing epiphora on exposure to dust pollution. Calves showing bilateral epiphora (n=12) and no epiphora (n=6) with mean age 6 months and weight 56.0 kg were included. The average periorbital matting of the facial hair extended to 4.8cm. The value was 4.92 ± 0.59cm and 5.17 ± 0.90cm in the eyes subjected subsequently to epibulbar or subpalpebral injection respectively. Schirmer Tear Test values (Mean ± S.E) in epiphoric eyes (27.67 ± 3.30mm/min) were non-significantly higher than non-epiphoric (21.00 ± 0.97mm/min). Conjunctival swabs revealed Gram positive and -negative commensals. One eye was injected 0.5mL of the combination epibulbar and the contralateral subpalpebral routes. Calves in the control group were received 0.5mL normal saline. In six calves, the epiphora subsided in three days and in four more it took seven days. Compared to day 0 values, the reduction of 98.9 ± 7.1% and 86.1 ± 10.9% respectively in facial matting did not differ significantly (P > 0.05). Recurrence or additional cases were not noticed subsequently in the farm. Moderate rains nine days following treatment of calves settled dust and reduced air pollution. It is concluded that the eyes in the calves are more prone than adults to the dust pollution. Both subpalpebral and epibulbar injection of gentamicin-dexamethasone are similarly effective in epiphoric calves. The studies evaluating the deleterious effects of air pollution on the ophthalmic health in food animals deserve more attention in future.