Recently we have seen an increased presence of Keds becoming an issue on farms predominantly in the Omarama, Palmerston and Ranfurly areas, particularly in fine wool sheep. Due to compulsory plunge dipping of all sheep with organophosphate dips, in the past, Ked populations around the country were greatly reduced. However some populations have started to re-emerge.
Sheep Keds are blood sucking wingless flies that cause irritation leading to fleece damage by rubbing as well as reduced growth rates and wool discolouration from digested blood in faeces. Anaemia due to blood loss from high burdens is possible especially in young lambs.
Dipping with a product that has persistent activity for longer than the time it takes for pupae to hatch is required to kill all newly emerged adults.
It is important to form a plan with a combination of dipping and drenching to have the best result in eradicating Keds from your farm. Best results come from using Cyrex for fly control as well as a lice dip that is effective against Keds. This will either be a pour-on off shears or jet/shower dip with at least 4 weeks wool on. Principals for control, as with lice control, are to have complete musters, secure boundary fences and quarantine dipping of any bought in stock. To prevent growth limiting effects on lambs each drench should be either a Matrix or Switch, containing abamectin.
For any questions or to form an eradication plan talk to one of our Vets at the Blue Cross Veterinary Centre,.