Hello my layers have crd and it's affecting production and their eggs are small please what drug can i use except tylodox it's too expensive they're calling it 4k now

Amoxicillin, oxytetracycline, erythromycin, spiramycin, lincomycin, quinolones, norfloxacin, enrofloxacin, levofloxacin, tiamulin, levofloxacin.

For E coli that may accompany crd, add colistin or Neomycin to any of the above drugs.

You have to reduce environmental stress too for drugs to be effective. Avoid overcrowding, high or too low temperature, dust and ammonia smell from droppings. Warning: Ammonia smell from droppings will keep causing disease outbreaks. Keep their pen clean and don't allow droppings to accumulate.