However, a review of advertising practices is planned "to determine if additional guidance is needed or if the existing controls on advertising need to be changed for antibiotic veterinary medicines."
MPI says the report, Antibiotics Sales Analysis 2009-2011, found a 19% reduction in antibiotic use over the three years surveyed.
"We understand that this reduction is largely attributable to positive changes in production animal management in the pig, poultry and dairy industries," says MPI deputy director-general standards, Carol Barnao.
"These industries have reported a move towards non-antibiotic preventative treatments like vaccination and changes to on-farm practices to decrease their antibiotic use."
DairyNZ and the Dairy Companies Association of New Zealand (DCANZ) say the report highlights the importance of animal owners working with veterinarians to manage antibiotic use.
"Ensuring [antibiotics'] future effectiveness is in everyone's interest," says DCANZ executive office Kimberly Crewther.
"The dairy industry's position on antibiotic use is to use as little as possible without compromising animal welfare.... Prevention is the best approach.... This is especially the case for the key areas of lameness and mastitis."
DairyNZ chief scientist Dr Eric Hillerton says all dairy antibiotic treatments are recorded and records of use are independently audited annually by processors to manage milk quality risks and ensure only healthy animals contribute to milk supply.
"The national mastitis control programmes developed and implemented by DairyNZ and industry partners ensure the quality of milk supplied from farms is world leading," he says, noting New Zealand has only half the mastitis of the USA and a quarter of the UK incidence.
DairyNZ worked with the International Dairy Federation to produce a guide to prudent use of antimicrobial agents in dairy production and it is being customised for New Zealand, says Hillerton.
Crewther says the dairy industry is "committed to sensible and expedient use of antibiotics to safeguard animal health and welfare, and ensure a safe product for consumers."
MPI says considerable consultation with industry and selected individual veterinarians went into the report's compilation which is why it is two years out of date, says MPI. However, having established procedures for such a report the next one, covering 2011-2013, should be released June 2014. Thereafter, reports will be released annually.
Barnao says the 2009-11 analysis revealed areas needing further study, including increased use of injectable tylosin in cattle, third and fourth generation cephalosporins in production and companion animals, and reported marketing and choice of antibiotics based on convenience rather than most appropriate therapeutic choice.
"As a result of this information, MPI will gather further information and look at controls around the marketing and use of antibiotic products to determine they effectively manage risks associated with antibiotic resistance," says Barnao.
Tylosin use is important because it is in the class of antibiotics known as Macrolides, a class important to human medicine. A trend of increased use in cattle as a convenient once-daily treatment for mastitis needs investigating to ensure the potential risk of antibiotic resistance is limited, and it is the most appropriate treatment. It is critical to the management of certain infections not responsive to other antibiotics, says MPI.
Other convenience factors which could be compromising use and MPI intends to investigate include zero or short withholding periods, and "one shot dose" products.
New Zealand's use of antibiotics and resistance status was surveyed by MPI in a baseline study covering 2009-10. It found farm use to be responsible and in compliance with veterinarian advice, and what little resistance was found had no direct implications for human health. There did not appear to have been an increase in resistance since previous studies, and compared with 2009 data from Denmark resistance among bacteria from New Zealand pigs and poultry was either lower or not significantly different.
MPI says control of use of veterinary antibiotics in New Zealand meets international best practice but the latest report provides some opportunities to verify practices and further refine controls if needed.
The New Zealand Veterinary Association and industry groups such as NZ Pork and the Poultry Industry Association New Zealand (PIANZ) have published guidance for the prudent use of antibiotics within industry. Further guidance and updates from NZVA are in progress.
The MPI report is at http://www.mpi.govt.nz/Default.aspx?TabId=126&id=2121
