Annabel is a
veterinarian at Vetlife Culverden
Antimicrobial resistance (AMR) is one of the top global public health and development threats identified by the World Health Organisation. It is estimated that bacterial AMR was directly responsible for 1.27 million global deaths in 2019 and contributed to 4.95 million deaths(1).
By now most farmers will be familiar with the traffic light classification of antibiotics produced by the NZVA. Under this system we use green, orange and red to distinguish between important, very important and critically important antibiotics (CIAs), respectively. CIAs are classed this way due to their critical importance in human health. As the same antibiotics are used in both humans and animals to treat many of the same bacterial infections, the choices we make when treating animals can have an impact on treatments available in human medicine. The rate of development of new antibiotics is painfully slow and we still routinely use the first antibiotics discovered.
Understanding NZVA’s Traffic Light System
Green antibiotics include such antibiotics as procaine penicillin, the white penicillin most commonly used on farm. Orange is used for antibiotics which may be more specialised in their use and which have a higher degree of importance than green-clasified antibiotics.
Red for CIAs does not mean do not touch, but a veterinary diagnosis is required on a case-by-case basis to determine whether the product is the most appropriate choice. This may involve sampling for culture and sensitivity testing prior to treatment.
Tracking antibiotic use in New Zealand
Each year NZ Food Safety at MPI produces the Antibiotic Agricultural Compound Sales Analysis(2). This document looks at kilograms of import sales of antibiotics that are labelled for animal or crop use in New Zealand. It does not include antibiotics registered for humans. This report is currently the most accurate information we have on usage of antibiotics, since there is no collation of administration rates.
The 2024 sales report released in October 2025 had some positive stories to tell. Overall sales of antibiotics have fallen for the seventh year in a row. Total antibiotic sales in 2024 were 26% below the average for the previous five years. From 2019 to 2024, sales declined from 61,147kg to 37,858kg.
CIA sales declined from 5,253kg in 2019 to 1,461kg in 2024. This is largely due to an intentional change in prescribing practices of vets during annual future authorisation consultation with farmers. We have achieved this as a joint effort and we can consider this good progress in terms of antimicrobial stewardship. Sometimes it is tempting to reach for the red antibiotic because it is more convenient, but it is probably the less appropriate choice when thinking long-term.
Why prudent antibiotic use still matters
While we can be proud of our progress, it is important to continue to be prudent in the use of antibiotics and to consider other allied strategies such as biosecurity, PPE and vaccination. The lower the challenge facing our animals, the less reliance we will have on a precious, limited resource.
References:
