Extreme mites- 2 deaths 1 ill - help please

[cantraig]

Ok so I had 7 chickens mixed breeds (I'm a beginner)
I had 2 polands, 3 warrens and 2 sussex.

2 weeks ago one of the polish became ill and passed away the same day. 2 days ago the 2nd polish became ill and also passed the same day. They where supposedly around 6 months old however they where laying every day since day 1 of having them, I know polands aren't very good layers but these two gave us at least 6 eggs each every week I thought we just had a good pair!
With both dying so close together I now presume that the seller has lied about the age and that they are older birds. The 3 warrens and 2 Sussex however have grown and only started laying around 2 months ago so I know these where young hens.

Since the first death eggs hit an extremely low of only 1 a day. I found that I had a very bad mite problem. They where everywhere!! They are also moulting, so I have been today and spent £50 on mite powder for the birds, a mite spray for the coop and run, and a vitamin boost for the water.

When I got to them this morning I noticed one of the warrens where acting alike the two that died, very slow movements and keeping to herself. It is wierd they are there usual selves but then suddenly the next day become dopey and rapidly down hill from there until 8-12 hrs later when they die.
The warren that is not her self today does have abit of fight in her as she seems to be walking around occasionally, I have also seen a big lump of feathers been plucked from her neck.
I have treated everywhere for mite, and the birds. They now have there vitamin supplement and everything has been thouroughly cleaned.

Is there any more I can do??

 

[Yorkshire Coop]

Sorry to hear about your deaths. Mites could have caused them to die they suck the birds blood until it makes them anaemic and very sick. You have done the right thing having a really good clean but I would still continue to treat for mites every 3 days. By doing this you will kill more mites that may hatch. They are very good at hiding in nooks and crannies in the coop or have look when it's dark with a torch you may see more. I have found the best way to get rid is power wash your coop out you will see more emerging as the water disturbs them, let it dry then spray with a mite kill solution. Then when that's dry liberally spread diatom earth everywhere especially on and at the ends of perches that seems to be one of the places they like hiding the best. Molt and mites can both cause hens to stop laying and lethargy in the birds. Good that you got them some vitamins should give them a boost. Good luck with your mite problem hope your birds are back to full health soon