Sally,
I was considering buying birds from a very well known breeder in New York, but I turned them down because this breeder vaccinates his birds for laryngotracheitis.
Many people recommend vaccinating for it (especially show birds) but it's a live virus vaccine so once your birds are vaccinated, they will become carriers and shed the disease throughout their lives. This is especially true of the CEO (chicken embryo origin) version of the laryngotracheitis vaccine. Some claim that the TCO (tissue culture origin) version of the vaccine won't cause birds to become carriers, but I talked to a couple of different poultry vets who have researched this vaccine and they said that both vaccines will cause birds to shed the disease.
I don't want to vaccinate my flock for this because it will limit my sales to others who have also vaccinated. However, I would like to get my hands on the recombinant vaccine that rbaker was talking about for Mareks and LT. This particular one doesn't cause birds to become carriers.
After I decided not to buy birds from this breeder, I talked to some people who have. For some people everything went fine, but for others, they lost the majority of their flocks due to the new vaccinated birds shedding the disease (lost $1,000's worth of birds). I'm glad I decided against buying them.
