I would definitely inform her that you suspect her birds may have IB. She may already know it. She may be getting out of the business because of that and if so, it is very irresponsible of her to sell her birds. Highly contagious, it will move through the flock in 24-48 hours. Your hens that recover will be immune but will be carriers. Definitely push the fluids with electrolytes because it can lead to gout because of the kidney damage. Their egg quality will likely be different because IB causes permanent ovary damage. When they resume laying, the eggs may be misshapen, soft, thin, rough, ridged shells with thin albumen. They may not lay again. It doesn't survive more than a week off the bird. Most any disinfectant will work for the coop. You said you have multiple pastures so if that includes multiple housing options, you could house the birds in one building while they recover, clean the other building and move them there after 10 days and disinfect the other building. If you aren't particularly attached to your birds, your best course of action would be to cull the flock and start over after thorough disinfection. This is another example of the need for quarantine of new birds. As far from your flock as possible for as long as possible. Work with your birds first each day before tending to the quarantine area. Use different clothes and shoes and wash up between flocks. http://www.desu.edu/sites/default/files/u538/QandI_2 pager.pdf http://agriculture.vic.gov.au/agric...ry/quarantine-advice-for-small-poultry-flocks This is the point often overlooked in the rush to administer antibiotics. Truth is, of all the things that can cause respiratory problems, bacterial ones that can actually be cured with antibiotics are a relatively small percentage of those.