November Vet’s Diary with Sam Morgan BSc MVDr MRCVS
The question us vets are most frequently being asked at the moment, in light of the Avian Influenza (AI) situation, is “How can I reduce the risk?”
In answer to this, previous years’ experience demonstrates the importance of good biosecurity.
Recognising the symptoms of AI early is important. Clinical signs vary greatly with Avian Influenza and can be seen as soon as 24 hours after initial infection (particularly in cases of a ‘high pathogenic’ strain). High mortality, dullness, a loss of appetite, depression, coughing, nasal and ocular discharge, swelling of the face, blindness, nervous signs such as paralysis and sometimes green diarrhoea are all also clinical signs. However, birds infected with ‘low pathogenic’ Avian Influenza may show milder clinical signs or none at all.
In terms of managing the disease, developing a biosecurity plan that works for you is the most effective way to reduce risk.
When we think about routes of transmission, the main route of AI transmission, however, is the faecal-oral route which happens when feed comes into contact with faeces on the floor. At the moment, spin feeding, and trail feeding is common practice but this does pose a greater risk. Hopper feeding is the recommended way of feeding as it helps to reduce feed and faeces contact. Placing feeders on raised platforms, so that any spilt feed from the hoppers is inaccessible to the birds, is also a good idea. The food is out of the mud and dirt, dry, and good quality. We would recommend moving feeders on a regular basis and cleaning up any feed spillages too.
People moving between sites can act as a way of spreading the disease, if they have been in contact with sick birds. What the vets at St David’s have been actively encouraging is, where possible, for people to have designated parking areas for external visitors, and to use site vehicles to reduce transmission from shoot to shoot. We would also recommend spraying vehicle wheels and under arches with a DEFRA approved disinfectant at the correct Poultry Orders concentration.
Strategically placed foot dips with a DEFRA approved disinfectant at the Poultry Orders concentration – positioned on arrival and between drives – are also an effective method of reducing transmission. It is important to remember that rainwater can dilute the disinfectant, or for organic material such as mud from boots can break it down too, so make sure to use fresh disinfectant (changed every 7 days, or sooner if it becomes contaminated), wash boots off first, and make sure the dip is well covered.
Remember that some strains of AI are zoonotic, meaning transmission to humans is possible in rare cases. Personal hygiene – wearing clean clothes and washing hands – is therefore also very important, we all remember what we were told during COVID-19!
Precautions should be taken to limit wild bird contact; such as the use of bird deterrents; netting all ponds in close proximity; avoid feeding ad-lib; and if feed is spread on the ground, ensure it is consumed in a short period of time. The quick removal and correct disposal of dead birds is also very important.
If you have any concerns at all, we would suggest speaking to your vet who will be able to provide tailored biosecurity advise for your site. There is no ‘one size fits all’ and there are lots of factors to consider.
In the meantime, all businesses should be registered with APHA. This is a legal requirement if you keep 50 or more captive birds at anytime during the year. Being registered means that you get relevant updates of local outbreaks in your area, and it allows them and us to help keep a close track of AI – so it benefits everyone to register.
Further useful advice can be found on the DEFRA website: Avian influenza (bird flu) – GOV.UK (www.gov.uk) and the GWCT guidelines also outline helpful biosecurity measures: Bird flu and Gamebirds: revised guidance issued – Game and Wildlife Conservation Trust (gwct.org.uk)
Originally written for November’s monthly feature of Countryman’s Weekly – ‘The Vet Diaries’
