The PoultryDVM dosage appears low, and I would suspect they have given the cattle dosage instead of for chickens.
Here are a couple more sites for dosages of oxytetracycline injectable for chickens:
http://www.poultrymed.com/Tetracyclines
https://sites.google.com/site/zdhfp...ramycin-alamycin-la-oxytetracycline-injection
@Eggcessive, can you double check that oxytetracycline dose? I think I remember reading that it's in the 25-40 mg/kg range.
The Merck site has doxycycline for pet birds:https://www.merckvetmanual.com/exot...als/pet-birds/bacterial-diseases-of-pet-birds
Here are a couple more sites for dosages of oxytetracycline injectable for chickens:
http://www.poultrymed.com/Tetracyclines
https://sites.google.com/site/zdhfp...ramycin-alamycin-la-oxytetracycline-injection