Not sure you can get the pills anymore unless your vet will prescribe. I used to get it as a fish antibiotic, but those have been pulled. This one is from pigeon supply and is liquid. Other than shelf life, I don't think it makes a difference. I use the liquid and give with an oral syringe, it's not a problem.
I will list the various dosings I have found, and I'm currently treating one of my hens with it, a standard sized EE about 5.5 - 6 lbs and I'm giving her 0.5 ml of the liquid once a day, and she's responding well so far.
Dosings I have found and have in my book are:
"10 mg/kg twice a day for 5 days"
"15 mg/kg once a day for 5 days"
"20 mg/kg once a day for 5 days"
"For a 6 lb 14 oz chicken with a 100 mg/ml solution doses are
0.132 ml twice a day or
0.468 ml once a day or
0.625 ml once a day"
I have collected dosing over the years, and can't refer you to my original sources.
Plumbs veterinary Drug Handbook gives the 15 mg/kg once a day orally dose.
It does come as an injectable also, prescription only from a vet. Injecting it takes care and you have to move the site each time as it can cause tissue necrosis at the injection site. I prefer the oral for that reason.