Foot and Mouth disease – there but for the Grace of God?

Although the virus does not affect poultry directly undoubtedly some producers on mixed farms will become entwined in the necessary movement restrictions and, sadly, possible slaughter in infected areas.

For the rest of us, this catastrophe, so closely on the heels of the Swine Fever outbreaks in East Anglia and the Avian Influenza in Northern Italy, is a worrying development.

These problems demonstrate that contagious viral diseases know no national borders and the local and international repercussions affect us all. The Italian influenza outbreak meant the death or slaughter of nearly 20 million birds and the costs are likely to exceed those of the Pennsylvania outbreak in the mid 1980’s which, itself, is thought to have cost the US industry some $350 million.

Without scare mongering, it is a useful time to reflect on the two significant notifiable diseases of poultry, Newcastle Disease (fowl pest) and Avian Influenza (fowl plague).

Notifiable diseases

As the term suggests ’notifiable’ means that if either disease is suspected in your birds, you have a legal obligation to notify or report those suspicions to your local MAFF office without delay.

The EU has in place statutory control measures in the event of outbreaks of either disease being confirmed. These would include:

- Slaughter of infected flocks.

- Setting up of 3 Km restriction and 10 Km surveillance zones around infected flocks.

- Investigations into the source and spread of the diseases.

So how do you know if you ought to be suspicious of either disease in your flocks?

Both diseases are viral, are highly contagious and capable of causing significant sudden mortality and accompanying drops in egg production. So any significant sickness or deaths in your birds should always be discussed with your veterinary surgeon.

Newcastle disease

Classically, Newcastle disease has been associated with some or all of the following:

High mortality (variable dependent on the age of birds and vaccination history).

- Nervous signs (difficulty walking, wing paralysis, twisted necks).

- General malaise and sickness.

- Green diarrhoea.

- Non-specific respiratory signs.

- Sudden severe drops in egg production

Avian influenza

In the case of Avian Influenza, this may be seen as:

- High mortality (up to 100%).

- So called ’cathedral syndrome’, birds going exceptionally quiet and listless.

- Severe respiratory signs and swollen heads.

- Sudden severe drops in egg production.

What can I do to minimise the risk of introd uction of diseases to my birds?

Vaccination

Obviously in the case of Newcastle disease vaccines (live and dead) are available to protect birds against the most severe effects of the virus. Historically, the highest mortality during outbreaks has been seen in young birds in rear where the vaccination programme has not yet been completed.

- If Newcastle disease is confirmed in UK, emergency live vaccination ’top ups’ of birds in lay may be of benefit, after taking veterinary advice.

- The advice, therefore, is to treat all vaccinations seriously paying good attention to technique and uptake by the birds.

- Blood sampling after vaccination should help you to monitor the success (or otherwise!) of this technique.

- There are no commercial vaccines available for Avian Influenza (vaccination may be made available by Government in the face of a disease outbreak), therefore control is aimed at exclusion of the virus from flocks by employing effective biosecurity measures.

Biosecurity

- See our previous article on the subject in The Ranger.

- Keep all visitors to an absolute minimum.

- Ensure adequate protective clothing (especially boots) are available for all necessary visitors.

- Place foot dips at the entrance to all houses.

- All vehicles and equipment entering the farm must be clean and adequately disinfected.

- Provide a wheel and wheel arch spray at the entrance to the premises.

- Exclude all wild birds (especially ducks and other waterfowl which can carry virulent Newcastle Disease and Avian Influenza).

Obviously, our free range flocks must by definition be ’at risk’ from such wild birds, but they must be actively discouraged from mixing with your birds by avoiding exposed poultry feed or open water which may attract such birds, especially migratory species in winter months.

Conclusions

- Any disease challenging your birds can cause distress and financial loss.

- The notifiable diseases of Newcastle disease and Avian Influenza bring with them a special set of regulations, problems and heartache.

- Stick to a strict biosecurity programme for your premises.

- Regularly inspect your birds for signs of ill health and seek specialist advice without delay.

Remember – expect the unexpected.