Preparing for flystrike this summer

Blowfly strike is a common problem in sheep flocks during the spring and summer months, and can also less commonly affect cattle, goats and alpacas. In recent years, unfortunately, changing weather patterns mean that the typical ‘flystrike season’ seems to be starting earlier in the year, and lasting longer. It’s increasingly important to be vigilant for flystrike, take measures to prevent it, and be prepared to manage cases when they do occur. 

You can check the NADIS blowfly forecast at https://alerts.nadis.org.uk – as of writing, all of the south west is deemed a ‘high risk’ area! 

Why is flystrike fatal? 

The condition is painful and distressing for the animal, which will stop them from grazing normally and result in rapid loss of condition. The digestion of organic tissue by the maggots triggers a release of endotoxins – these in turn attract more adult flies to lay more eggs. The animal will then develop septicaemia, either from the endotoxins, or from a secondary bacterial infection, which is rapidly fatal. 

Spotting flystrike early gives the animal the best chance to recover. During hot and humid weather, sheep flocks should always be checked at least once a day for any animals showing early signs of flystrike. In particular, make sure you check animals that are: 

• Lame (flies may lay eggs in foot rot lesions) 
• Scouring (soiled wool provides the perfect environment for eggs) 
• Grazing in sheltered areas, like woods 
• Not tail-docked/have long tails 
• Not dagged, or have not yet been sheared 

When observing from a distance, you will see affected animals isolating themselves from the group, obsessively nibbling at their back, and flicking their tails. Lame animals will suddenly get worse if they suffer flystrike in the foot. However, you need to examine animals up close too – patches of damp, dark, smelly wool are the most obvious sign of flystrike before you spot the maggots themselves. 

2. Apply flystrike treatment. You MUST make sure the product you’re using is licensed to “treat established blowfly strike”, as products that only “prevent” flies cannot kill the maggots. 

Please contact the farm practice and speak to our vets about the most appropriate products for your animal.

3. Give pain relief and take steps to prevent secondary bacterial infections. Once the skin is dry, you can apply antibacterial spray to the lesions to prevent them becoming infected. In more severe cases, your vet may advise an injectable antibiotic too.

4. Inspect the rest of the group for any more cases. If the rest of the animals seem unaffected, then apply a fly preventative product if not already done so.