I never recommend using those combo treatment medications, since you would be giving medications not needed. They can be harmful. That one med treats mycoplasma, canker, coccidiosis, and also is a wormer. You describe sneezing. Are there other symptoms, such as bubbles/foam in one eye, a swollen eye or face, or crackles when they breathe? If not, you could be dealing with something environmental or feed irritating the nostrils. Or it could be a virus, such as infectious bronchitis. Don’t assume that they have MG (mycoplasma.) Get some testing of the SICK birds with symptoms. Don’t give a vaccine without knowing what they have. Do not plan on selling hatching eggs until you get testing. There are a couple of labs such as Zoologix and RAL labs who can send you testing materials that you collect and send back to them for PCR testing.
