Possible mites infestation!!!

[Chicklady92]

Over the past three weeks after I brought home a Brahma hen from a 72 year old lady my flock of 20 has been acting strange. The behaviors are mainly in my Rhode Island Red hens. I do believe it may be mites but here is their symptoms...
Messy butt feathers- look muddy/poop (only on one RIR and one Legbar)

Decreased egg laying
Pale combs (only with my Rhode Island Reds and my one Cream Legbar, the rest have bright red combs but by 8am they are bright red again)
my one Cochin Bantam roo has inflamed feet around his feather shoots

They are eating/drinking and roaming around as usual. I put a few drops of Ivermectin pour on, on the backs between the wings last night. I have picked my birds up and I cannot see any mites and I just recently cleaned both coops thoroughly as I do once a month or more as needed. They are offered fresh water with electrolytes in the summer and plenty of shade. I don't have a lot of money as I'm a stay at home mom so the cheaper the better for treatment. I just want my birds healthy again

 

[Epiphany]

Hi!
I'm sorry to hear that your girls aren't feeling on top of their game! I'm not here with definite advice, just some insights.
First, both lice and mites are pretty easily visible as they are big enough to see and move a lot, so if you've checked thoroughly around the vent and under the wings are see nothing, I wouldn't worry about that being the issue.
Second, a few of my girls also have messy butts sometimes: they occasionally have messier poop and it can get stuck, so unless it seems to be an abnormal amount or is blocking their vents, that alone doesn't seem too worrying... if you are worried though, the electrolytes are a good idea in the case that they have diarrhea, which can dehydrate them.
Third (sorry this is long!): the laying of a hen is affected by many, many variables, which can make it difficult to determine if something is really wrong: light, stress, molting, an underlying worm problem, etc. If you don't think that it's stemming from light, molting, the stress of adding a new bird, or some surrounding environmental factor, you could try worming your birds, supplementing their diet with more nutrients, or decreasing the flock size.
Finally, for your roo's feet: if it seems to be infected or is hurting him, give his feet a gentle wash in some warm water and then clean it with a disinfectant. Keep him on clean bedding and keep doing this until it resolves. My feather footed birds always seem a little gross around their feet, though, and I think it may just be the way it is.
I would see more reason to worry if your hens were showing obvious signs of illness, but from what I read, they seem to be OK other than poor production and pale combs? If this were my flock, I would continue the use of electrolytes (no harm in that), take the iffy birds out of the flock, and monitor the health of the overall flock closely until the issue is resolved.
Hope this helps you somewhat! I know how it feels to be worried about your gals.
Epiphany