FIDIN reports the total amount of antibiotics (active ingredient in kilograms) sold in the Netherlands, at the level of pharmacotherapeutic groups. The data about use of active substances are based on sales data of members of FIDIN and are estimated to cover about 98% of all sales in the Netherlands. Actual consumption can differ from the amounts sold, as a result of stockpiling and cross-border use. The figures give information about the total sales for all animals, not per individual animal species.
The EMA collects harmonised data, primarily based on overall sales of veterinary antimicrobial agents. To ensure that the sales data provided by the EU member states are harmonised, an ESVAC Data Collection Protocol has been developed and a call for data has been sent to most EU member states. To fully implement the ESVAC protocol, FIDIN had to adjust the levels of active ingredients for several products, taking into account the salt and ester formulations and calculation factors of active ingredients expressed in international units. These corrections led to a reduction of the calculated total amount of active substance by approximately 4%. The sales figures as from 2010 were based on the ESVAC template; the figures of 1999 to 2009 were re-calculated and corrected accordingly.To adjust for trends in the size of the animal population the sales of antibiotics for therapeutic use were also expressed as grams of active ingredient per kilogram of live animal weight (Figure 3.1). For this purpose the FIDIN sales data were related to the total live weight of the average number of animals present in the Dutch livestock farming sector (pigs, poultry, veal calves, other cattle and sheep). For this analysis the following average weights were used: veal calves 172 kg (i.e. the weighted average of white veal calf 164 kg and rosé veal calf 192 kg), other cattle 500 kg, turkeys 6 kg, other poultry 1 kg, fattening pigs 70 kg, sows 220 kg, piglets (< 20 kg) 10 kg, sheep 60 kg. This yields information about the trend in the sales of therapeutic antibiotics in grams per kilogram of live animal weight present in the Netherlands over the years, consequently taking yearly fluctuations in the size of the animal population into account.