News & Advice

Timing right for flystrike prevention?

Dec 5, 2019 | Dry stock, Dry stock animal health & welfare, Sheep

Joe Conroy, Veterinarian, Anexa Vet Services

As the temperatures rise in the lead up to the summertime, so to does the risk of flystrike in the sheep flock.

Flystrike is caused when an ideal environment is created at skin level in the fleece of the sheep (wet/moist wool, urine/faecal staining). This occurs mainly around the crutch or down the backline. Blowflies lay eggs on the skin surface which hatch and start feeding on the skin, creating discharging wounds, which in turn attract more flies to lay eggs and exacerbate the condition.

Early signs of flystrike can be generalised discomfort, stamping, tail twitching and biting at the affected area. As the strike progresses the sheep will stop eating and become depressed due to toxic ammonia secretions from the maggots. As the wound grows it begins to discharge, the wool around the wound may start to fall out and the area becomes blackened. Very quickly this develops into severe dehydration and ultimately death.

By the time the sheep show obvious clinical signs, treatment is often too late. If they do not die, treated sheep often take months to recover the loss in condition and wool quality.

As we all know, prevention is always better than the cure! A key point to note is that flies need to be attracted to the sheep in order to lay their eggs, so creating unfavourable egg-laying conditions is critical here! Unfortunately, we cannot control the weather, so the focus is at the sheep and environmental level.

  • Docking lamb tails helps to reduce the tendency for dags to form
  • Shearing/crutching keeps the wool length from attracting dags, and keeps the skin level both cooler and drier
  • Adequate parasite control programmes aid in reducing faecal staining and contamination
  • Removing ideal breeding grounds for blowflies (carcasses/organic waste) helps keep numbers down
  • Chemical prevention is important and ties in with the timing of shearing

• There are different products/methods depending on facilities available and length of action required
• Proper application is pivotal to protection. Applying to dirty/soiled wool can reduce the length of protection

It is important to get the timing and balance right in order to reduce the risk of flystrike in your flock this coming summer. We are more than happy to assist with planning so feel free to get in touch with one of the Anexa team to tailor the plan to your situation.

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