Registrants of prescription veterinary medicines containing antibiotics are required to provide an annual summary of sales to NZFSA as a condition of registration.
The data is used to look for trends in sales and to help in the development of risk management policy.
"The sales information provides a snapshot of registered veterinary antibiotics of interest," said NZFSA Director Agricultural Chemicals and Veterinary Medicines, Debbie Morris.
"For example, we would want to know if there was an increase, say, in the use of certain antibiotics that might get into the food chain and decrease antibiotic effectiveness in humans. However, the data presented over a five year period shows no trends that would indicate antibiotics are not being used as intended."
Most of the fluctuation in sales over the last three years has been driven by sales of zinc bacitracin, which still represents 36 per cent of all antibiotic by weight, 94 per cent of antibiotic usage in the pig and poultry category, and 93 per cent of in-feed and water usage.
Zinc bacitracin is an antibiotic that has been in use since the 1940s and is approved for animal use in many countries.
While it has uses in humans (mainly as a topical antibiotic applied as a cream) it is not considered a vital medicine for human health.
"Increased sales or use cannot be interpreted as increased prescribing frequency without considering changes to the animal populations," said Debbie Morris.
"Large variations in sales are most likely to occur with products that are used in small quantities to manage disease outbreaks. Any changes that might represent a significant alteration have been highlighted in the report."
However, Debbie Morris said that while the latest report does not show any trends of concern, the information is still very useful.
"In gathering this data NZFSA is in a unique position to be able to see the big picture of antibiotic use across the sectors. It's heartening in the latest data to find no cause for concern."
NZFSA has published the latest report on Antibiotic Sales at http://www.nzfsa.govt.nz/acvm/subject/antibiotic-resistance/antibiotic-sales-2005-2007.htm
Antibiotic Sales Show Little Change
NEW ZEALAND - Total sales of prescription veterinary medicines containing antibiotics in New Zealand in the 2006/07 year have decreased to levels similar to the 2002/03 year, and are down 11.9 per cent on 2005/06 sales, according to a report from the New Zealand Food Safety Authority (NZFSA).