Current incidence, treatment costs and seasonality of pinkeye in Australian cattle estimated from sales of three popular medications.

Pinkeye is an economically important ocular disease occurring in all cattle producing areas of Australia. This study was undertaken to estimate the frequency of occurrence of the disease in Australia and treatment costs of the disease to the cattle industry using the sales of popular pinkeye medications as a surrogate indicator. Monthly sales data for Orbenin® Eye Ointment, Opticlox® Eye Ointment and Terramycin® Pinkeye Aerosol were analysed. We first estimated the number of cattle that can be treated with a syringe or a can and then using the data of sales of these pinkeye medications and the total cattle population of Australia, estimated the incidence of pinkeye. Probability distributions were used to include uncertainty around the estimates. Costs to producers were estimated based on retail prices of these medications. The results indicated that 732,864 syringes of Orbenin® Eye Ointment, 134,800 syringes of Opticlox® Eye Ointment and 27,755 cans of Terramycin® Pinkeye Aerosol are sold in Australia per year. Based on some assumptions of the number of cases treated by these drugs and number of cases left untreated, the number of cattle affected by pinkeye each year in Australia was estimated to be 2.80 million (95 % PI: 1.76, 4.65) or 10.25 % (95 % PI: 6.43, 16.97) of the entire Australian cattle herd. The cattle industry is expected to lose AU$ 9.67 million (95 % PI: 8.56, 13.11) each year just considering the cost of these three drugs. The results suggest that losses due to pinkeye in the Australian cattle industry are considerably higher than previously thought and should be used to inform the development of disease prevention and control policies.