2 months ago

Fly strike

Fly strike is a serious disease that affects millions of sheep and lambs in New Zealand.


Fly strike is caused by blowflies which lay their eggs on sheep. Maggots hatch from the eggs and burrow into the skin causing sores. If left untreated, fly strike will progressively become worse and cause increased respiratory, heart rate, ammonia toxicity and even death.



Affected sheep will not show any signs of fly strike until there are enough maggots causing damage to make the sheep feel uncomfortable. This maybe shown by sheep being ‘fidgety and nuzzling’.

As the maggots spread over the sheep’s body the wool in that area becomes black and begins to discharge. Then slowly the wool will begin to fall out, the sheep will stop eating, seek shade and be constantly fidgeting.

Once the fly strike has been initiated, further flies will become attracted to the site and the fly strike will spread further over the sheep. Resulting in disability and death.



There is a wide range of products available to help treat and prevent fly strike in sheep.

These range from sprays, dips and long acting pour ons. All available or able to order from Murrays Veterinary Clinic.

What you choose to use will depend on the amount of sheep you have and if you want to either treat or prevent fly strike, chat to one of our vets.



Dirty, wet or injured skin attracts blowflies, so it is important to keep sheep clean by removing dags and shearing when the wool is becoming too long.

Ensuring  that sheep are drenched regularly will prevent any stock from getting diarrhoea that would attract the flies.


 Phone our vets on 03 489 5540 for advice.