Dergall - new red mite treatment

Posted by Francesca Taffs

A Chicken Vet blog

The pesky red mite is the bane of the chicken keeper and all chickens! Add into the mix the northern fowl mite, which destroys plumage, and the scaly leg mite, which causes crusting and sores on the chickens’ legs and you have a mite time-bomb!

Dergall is a non-toxic and food-safe treatment which is applied as a spray to the chicken house and can also be sprayed onto birds without causing any harm. It works by mechanical action on the surface of where it is sprayed, creating a three dimensional structure (3D-IPNS™) which immobilises and traps the mites, destroying them. Dergall blocks their breathing apparatus, causing them to suffocate, dehydrate and die and carries on working for approximately three days after it has been applied.

Mixing and using Dergall is easy: mix into clean water at the rate of 10ml to 1 litre, a little goes a long way. Make the product up fresh to spray inside the poultry house, preferably when the birds are in darkness, or at the end of the day to maximise efficacy as mites only come out to find food when it is dark. Only use Dergall freshly mixed, so make up what you need, not the whole container.

Should you have a case of northern fowl mite cut off any debris from around the hen's rear (as this is where the northern fowl mite lays her eggs) then spray her rear and feathers with the Dergall at the same dilution, alongside the inside of the poultry house. Repeat in 5-10 days to destroy any newly-hatched mites from disturbing your birds. Destroy the feather clippings as you want to remove as many mite eggs as possible.

For cases of scaly leg mite, and to prevent it arising in your flock, you can either spray or dip the birds' legs into Dergall at the same dilution of 10ml to 1 litre of water. Repeat in one week to destroy newly-hatched mites.

Dergall is available from the Chicken Vet in 100ml bottles with an integral measure. 100ml will make 10 litres of spray solution. Visit for more information.