Chlortetracycline is an older antibiotic and member of the tetracycline family. It has historically been used to treat avian chlamydiosis. However doxycycline is preferred. Chlortetracycline has also been used for prevention of coccidiosis, caused by E. tenella, E. necatrix, E. acervulina, E. maxima, E. brunetti
, and E. mivati
Egg Withdrawal Period:
- In Australia: Chlortetracycline is labeled for use in the drinking water of chickens at doses up to 60 mg/kg (27 mg/lb) for < 5 days with a 0-day egg withdrawal.
- In Ireland: Chlortetracycline can be fed as part of a medicated feed to laying hens at a dose of 20 to 25 mg/kg (9 to 11 mg/lb) for 5 to 7 days with a 4-day egg withdrawal.
- In the United States and Canada: Is approved for use in laying hens producing eggs intended for human consumption when its given in accordance with each product manufacturer's label directions.
Prolonged treatment can have catabolic and immunosuppressive effects, reduce normal gut flora, and cause the bird to become more susceptible to opportunistic secondary infections.