Richard Turner MRCVS, Director at St David’s Poultry Team and Molecare Veterinary Services
Reducing the use of antibiotics in farm animals has moved to a priority for the government, but why has this happened and what can we do to achieve this aim?
In May 2016, the Antimicrobial Resistance Review commissioned by David Cameron and chaired by Lord O’Neill was published. This report looked in detail at the history of antimicrobial resistance and areas where it can be controlled. If you have not read it, it is worth looking up. It looked at antibiotic usage in humans and animals as well as their production. The recommendations are well thought out and it has become the backbone of the UK government response to the worldwide concern about antibiotic resistance development. We now have to start making changes to how and what we prescribe as vets, and farmers have to look at their husbandry systems.
In essence, there has been resistance to antibiotics for a millennium, but the level now seen in human medicine means that, unless actions are taken, it is likely we will revert to an era where there is no effective antibiotic treatment for bacterial infections. Resistance to antibiotics can be found in bacteria going back to the dawn of time. A cave was recently opened and found to contain bacteria with resistance to modern antibiotics although it had not seen the light of day for two million years. This is because many antibiotics are found naturally in the environment. The issue has become the amount of antibiotics being used in the last 50 years in both human and veterinary medicine. In the 1960s, it became clear that some antibiotics were effective animal growth promoters and their use increased hugely. This use in animals is now banned in the EU and USA, but elsewhere in the world large amounts are still being consumed.
The O’Neill Report also highlighted the role of the manufacturers in this problem. The drive to cheaper antibiotics has at least partly led to some companies manufacturing in countries where there are less controls on waste. In one case, a plant producing an enrofloxacin (now only used rarely in food animals and an important human antibiotic) was present downstream from the manufacturing plant in a river at least 1000 times the human toxic level. Whilst this was not in Europe, it was in a country where many of us go for holidays, consume water and eat food potentially contaminated with the resistance bearing bacteria. Then we travel back home and share our bacteria around our households!
So, the O’Neill report looked at all areas of antibiotic use and resistance development and to be fair, farming in the UK is not the major component of the problem. However, whilst there are no problems with antibiotics being found in food, there is a crossover of bacteria from animals to humans, either directly via food or via a third party, such as soil. This then leads to the possibility of resistance developing in humans. Various reports have highlighted the few remaining antibiotics which need to be reserved for human use only and these include the macrolides (Tylosin, etc.) and enrofloxacins. Whilst it has been argued for some time whether resistance is actually transferred, this debate is no longer important. The VMD is tasked with looking at antibiotic usage and setting targets to reduce overall usage in food animals.
The issue, to a certain extent, is that the data is based on sales of antibiotics and the species they are licensed in. When a product is licensed for more than one species it becomes difficult to decide where it is used. Targets will need to be based on better records and these in the future are likely to be on central databases. If the government puts targets in place, there will be a need for transparency and possibly auditing of use. In summary, the control on antibiotics will become tighter and it is possible that it might reach a point where only vets can give antibiotic treatments. Medicine records will be analysed on farm audits or centrally. In Holland, farms and vets are scored on their usage of antibiotics and a league table is produced which is then used to focus attention on those that use the most.
We have to keep the ability to use antibiotics where they are needed, but we also have to reduce their use where it can be replaced with better or different husbandry systems. It is sometimes argued that intensification leads to more antibiotic use. Interestingly, whilst animal density no doubt increases the risk of bacterial infections developing, good housing can give better and lower disease issues than uncontrolled extensive environments. There is no single answer, which makes the problem more difficult to define.
So how do we reduce or worse, replace antibiotics? The vets at St David’s Poultry Team have developed the concept of ABC, Applied Bacterial Control. This involves looking at all areas on the farm where antibiotics are used, understanding why they are needed and looking at other techniques to reduce the requirement.
If we take calf scour as an example, the ABC approach would be to first diagnose the various agents involved in the disease, define where they are coming from and how the animals are infected. Once this is clear, we need to put in place protocols to reduce the risk of infection and reduce the ability of the pathogen to colonise the calf. The first few days of a calf’s life is very important in the development of a normal gut flora. The new-born has an intestine with very little bacteria colonising it and it is the aim of ABC to help the ‘better’ bacteria survive and colonise the gut, helping the calf’s immunity to develop and produce products which will dissuade other abnormal bacteria to take hold. Changes to the environment, for example, adjusting the animal’s nutrition in both quality, quantity and availability will play a role. The use of focused vaccines might be essential but will only be a part of the plan. There are products such as essential oils which will aid in treatment, but these will not be as strong as antibiotics and will need early use. Once the ABC plan is designed for the individual farm, we will put in place a monitoring system to ensure compliance with the protocols and tests to ensure the animals are better protected.
The huge advantage with antibiotics is they can and have been used late for a condition. The expectation is that recovery is quick, but in many situations the original cause is not controlled. In summary, the reduction in antibiotics, which will occur possibly quicker than we would like, will require better management, better facilities and quicker interventions. It will not be easy and it will not be cheap, but it is possible and as long as the customer is willing to contribute to this extra cost, there is a way forward. There is very little time, as the government initially wants a 10% reduction in usage. Maybe this is small, maybe it doesn’t affect you because you use very little, but if we all do nothing, nothing will be achieved and more stringent controls will be applied.
If you would like more information on Applied Bacterial Control and how it might affect your farm, then please contact myself (Richard Turner), at the practice on 01392 872932 or email [email protected].