Its looking like a warm & wet autumn. That means every poultry keeper will need to prepare for battle against the dreaded red-mites 'Dermanyssus gallinae'. Think you don't have them? Well check again in the pitch black, shine a torch into the eaves of the hen-house and I'm pretty sure you'll find one.
These nasty little critters are vampires - hide from daylight and suck blood at night. They'll totally disappear during the day - turning a grey colour, then swarm over the inside of the henhouse at night - turning bright red when full of your hens' blood. They have an exceptionally speedy lifecycle, just one will become 240millon in 12 weeks.
Clues you've got them in your hen house:
Your house is made of wood or has a felt roof or has straw in it.
You could stop there - if you've got any of the above, you've got red mites
Your hens are reluctant to go in their house
White dust around the junctions of wood in the house
Tiny red specks on the outside of eggs
How to be sure?
Wait till its dark, then grab a torch and go check the hen-house. You're looking for the mites crawling over the walls, ceiling, perches & the poor hens. Don't see anything? Check again next week, then week after and the week after that.... all the time from Sept to Dec
What happens to the hens?
They'll be itchy at night, but as the mites don't live on the birds they'll behave quite normally during the daytime and their feather condition can look quite normal. The primary problem is anaemia as the mites are draining blood, so you'll get a range of signs:
Lethargy
Reduced egg production
Weakness & wobbling
Pale eyelid and mouth membranes
Weight loss
Death
How to get rid of them?
There's a good three-pronged approach to red-mites:
Stage 1: Prevention
Red mites despise Diatomaceous Earth. Its a powder made of crushed fossils, at a microscopic level its a blanket of razor blades. It will kill and deter the mites, but only where it lays. I add it to my hens dust bath all year - its fantastic for all the other lice & mites. During the autumn I use a powder puffer (found on ebay) to get it all over the inside of the hen house.
Totally organic solution.
Stage 2: Decontamination
If they've broken through your DE barrier, but the hens are still fine, then try stepping up the house decontamination. There are lots of mite-treating disinfectants out there. Having tried a lot of them, my preferred technique is:
Rehouse the hens for 7 nights - a week sleeping in boxes in the garage isn't the end of the world
Deep clean the house - everything goes, all the waste & straw goes in the incinerator
Every night, after dark, go up with a torch. Check they're all out swarming, then spray the house with permethrin. This is in household flea sprays.
Go back every night for 7 days in a row. Each morning you'll find a pool of dead mites on the floor, clear these away. Respray every night. By night 7 all of the eggs should have hatched and you should have broken the lifecycle and massively reduced their numbers.
Stage 3: Treatment
So they've won, your hens are looking sick. Don't panic, there is a good treatment. Launched in 2017 the results for Exzolt (Fluralaner, by MSD) have been excellent and has no egg withdrawal, 14 days meat withdrawal. Simply add to drinking water twice 7 days apart. You'll need to get it from your vet, so they'll need to see one of your hens and confirm its redmite - so remember to take a photo or sample of the critters in the hen house. If you're using your normal cat & dog vet they may not know about the new treatment as its aimed at commercial egg producers - please take this datasheet with you for them to read: http://www.noahcompendium.co.uk/?id=-467664
Good Luck in the fight against the red mite! It all be over at the first frost, so bring on winter..