Since you have accepted an answer on this page, I am going to go ahead and respond to this question. After you have accepted some of the ones that you have already asked, I will respond to more.
No kills means that all adoptable pets be given a chance to find a home. It does not mean that you will house sick or unadoptable animals for a lifetime. It doesn't even mean that you should house agressive animals. Adoptable pets means pets that have a chance of finding a home.
You need to put safeguards in place to protect all of your animals and you need to provide quarantine for sick animals and keep them out of the general population. A sick room works well for this.
Fleas and ticks are unacceptable. You cannot adopt out a dog that is covered in fleas and ticks. Prevention is part of health care in a shelter environment and should be done right after a bath on intake if the dog is an owner surrender or after the hold period is over for a stray.
Upper respiratory infections can be treated and you should do so, both in dogs and cats.
FIV + cats are not normally deemed adoptable, even in no kill shelters. If possible, you could find a humane group to help you place these pets.
I hope that this helps you some. If not, please let me know. I would be happy to help more.