Pro - Does anyone else's nest boxes get soaked in rain?

[HMTurner]

I think one of my chickens have coccidiosis. She has diarrhoea, flopped over comb, lethargy and has been off her food. Today the enclosure has many bright orange poos. I am also worried another of the chickens is now getting it as her comb is looking dull and slightly flopped. I have disinfected everything today. Is there any over the counter medication I can buy in England?

[Cat tails]

According to this website you’ll need a diagnosis from a vet to get the right treatment. I would contact yours and see what they say.

[mullethunter]

You can get Harkers coxoid to treat coccidiosis and I have successfully used it in chicks.

However, the symptoms you’ve described are quite vague and I wouldn’t be certain that coccidiosis is definitely what’s wrong with them, so I would follow cattails suggestion and take a sample to the vets for diagnosis.

[Luvachicken]

You can get the poo sample tested to see what they may have (especially any worms)

I don't know if they do specific tests like they do for dogs.

[HMTurner]

Thanks all. I took her to the vets two weeks ago. They offered no help in regards to diagnosis and just said they didn't think it was worms and gave me antibiotics. I am treating the whole flock with Harkers now as my other hybrid is showing signs. I just hope its not too late. 

[Beantree]

I don't think is coccidiosis because that would be blood in the poos which shows as black. Bright orange poos are cecal from a stressed bird and is possibly hair worms. Harkers is a wormer for pigeons and doesn't work for adult chickens (tried that). You need Flubenvet, which is best pre-mixed into the feed. There will be nothing better for them than to free range, but make sure there is no long grass. They naturally eat grass to clear out their digestive systems. Until you have a sample tested you won't know for certain, but it sounds like your vet isn't worth a second visit.