Retailer Map

Enter your town, city or postcode to find your nearest retailer:

A Guide to Fly Control: Why Treat, When Treat and What For

Flydown® TREATS and PREVENTS infestations by lice and flies in cattle and TREATS and PREVENTS infestations by ticks, lice, keds and established blowfly strike on sheep and lice and ticks on lambs. Use Flydown® for effective fly control.


Table showing which different parasites Flydown covers


Flydown® contains the active ingredient DELTAMETHRIN, a synthetic pyrethroid. It is a member of the second generation of pyrethroids in which the overall stability of the molecule is improved, with increased resistance to photo-degradation and bio-degradation as well as enhanced insecticidal activity. 

Deltamethrin is a potent neurotoxin in insects, causing a ‘knock-down’ effect. 


Applying Flydown® Simple dosing: - 10ml for cattle, 5ml for sheep, 2.5ml for lambs (under 10kg of bodyweight or 1 month of age). Apply a single dose with a special 'Squeeze 'n' Pour dispenser pack or a Flydown® Applicator. Apply in one sport on the mid-line of the back at the shoulders. For blowfly strike in sheep, apply directly to the maggot infested area as soon as strike is seen. One application will ensure blowfly larvae are killed in a short time. In the case of more advanced strike lesions, clipping out of stained wool before treatment is advisable.

Fly control – why treat?

Effect of uncontrolled fly populations:

  • Reduced milk yield by up to 20%
  • Increased incidence of summer mastitis
  • Reduced calf weaning weight by up to 9kg
  • Reduced reproductive potential in sheep
  • Downgraded quality of wool clip
  • Welfare issue in both species


Table showing number of flies before economic impact threshold met: Horn Fly 200, Stable Fly 20, Face Fly 25 and Head Fly 10-20.


Fly control – when to treat 

Different species of flies are active at varying times of year. This means a summer long threat is present with waves of irritants emerging all season long. Regular, frequent treatment is required throughout the period of risk to keep existing flies, as well as any newly emerging populations under good control. 

If you delay treatment until significant numbers of flies are noticeable, it is already too late to adequately control fly numbers! Reproduction of the existing population will have already commenced, meaning hundreds to thousands of eggs will be lurking in the surrounds, waiting to hatch and compound the problem. Start treatment early before a problem even arises to maximise the success. 



For more information on Flydown® please contact your local retailer or call us on 01228 564498. 

9th June 2021

We use cookies in order to give you the best possible experience on our website. By continuing to use this site, you agree to our use of cookies.