Okay so two of my chickens have a canker in there beak same size half and half in and outside like a lump. Iodine or blue kote wont help. I dont want to use metronindazole pills (I have the 250mg) since I want them to be antibiotic free. I saw in other posts that I can use copper sulphate apple cider vinegar dilute in water for 3 days. I want to try that method. I cant find copper sulfate anywhere my feedstore has it for 30 bucks after researching and looking I came out and edend with Zep drain product the active ingredient is copper sulfate 99% percent and 1% other ingredient. Will that 1% other ingredient kill my chicken? I also heard it can be used as a preventive for cankers. I have alot of pigeons and wild sporrows birds visiting my backyard I am fed up with that. Thats why I want to try that method. Hope to hear from previous experience. Thankyou!