Help poorly chicken

Hiya folks

I have a poorly chicken called ruby.  i think she has got coccidiosis.  i have started using vermx and milk. 

The chickens house is cleaned out everyday so is the food and the water with additional vitamins and apple cidar vinegar.  Not sure what went wrong.  Any help or guidance appreciated.  i love my chickens to bits x all 8 of them lost my cockerel 3 wks ago still hurts x