Veterinary Support - Biosecurity
Biosecurity is a term used to describe a plan or management procedures carried out to prevent the introduction of a pathogen (an infectious agent) on to a premise or to reduce as much as possible the chances that a pathogen can get in to the premise. It can be as simple or as complicated as you wish to make it and can either be designed to work for an individual pond or a whole country. For retailers and producers it is worth having a written biosecurity plan that is implemented as it will help provide confidence for your customers and defend you against any spurious claims. For a hobbyist it is worth considering so as to prevent the introduction of an infection to your pond.
The first stage is to identify what infectious agents you wish to control. In the case of koi this would be say a single problem such as KHV (a virus), Aeromonas hydrophila (bacteria) and various parasites such as Ichthyophthirius multifiliius the cause of White Spot, or all of them. You need to be realistic in what you can stop entering your pond. So for example since Aeromonas is ubiquitous in the environment (i.e. everywhere) it is unlikely you can stop it entering your pond but you could instigate management procedures such as using Virkon (a water treatment) to reduce the numbers of bacteria in your water.
Having decided what you wish to prevent entering your pond the next step is considering where the problem comes from. In the case of KHV this would obviously be either by the introduction of carrier fish or passing the virus from pond to pond by sharing equipment. These points of entry could be considered areas of weakness in your biosecurity and the aim of your plan is to close off these weak areas.
What else you need to realise is that not all methods of reducing infection may be appropriate for your situation or may be too expensive to implement. It may be that the risk of your fish acquiring a specific infection are low such as you are fully stocked and intend to not introduce further fish. On the other hand you may be a retailer acquiring fish from several sources with many customers coming through the door. In this case you have a high risk of introducing an infection. The plan you formulate needs to take in to account your own personal situation and it is impossible to formulate a generic plan that fits "all sizes". An example would be, do you need a separate building for quarantine purposes with controlled entrances, separate water supply, separate equipment, batch in - batch out with cleaning and disinfection between, showers, disinfectant baths/hand washes, clothing changes available for all going in to the building and coming out and monitoring for infectious agents which your staff might carry? This would help provide good biosecurity and may be highly appropriate for a government laboratory or top class breeding establishment but over the top for a small hobbyist pond. However, this example includes much of what one might need to consider. It may be worthwhile a hobbyist changing clothes after visiting a local retailer or visiting a local show, you might just have acquired something on your clothes that can still be infectious, remember KHV last for at least four hours in water. A change of clothing before visiting your fish might just stop you passing on an infection. Another point worth noting is that it is essential that you clean before disinfecting a pond or system. Dirt is very good at deactivating disinfectant or protecting the pathogen from the disinfectant.
It is probable that you already carry out some form of biosecurity either by having separate systems for new fish or by not sharing equipment. All that biosecurity is about is formalising those management activities and carrying them out to the letter. Biosecurity is about limiting the risks of introducing an infection and with good biosecurity in place there is no reason why you cannot continue to enjoy the hobby to the full, safe in the knowledge that you and your fish are safe.
Copyright Chris Walster BVMS MRCVS 2005
