How do I measure out 300 mg of Antibiotics?

[Eggcessive]

So there is going to be another lable that converts it? btw, who or what is an op?

So, what drug are you using? An op is the person who has started the thread asking for help, or original poster.

 

[chixcoop]

oxytetracycline

 

[Mutt Farm]

So there is going to be another lable that converts it? btw, who or what is an op?

Might be another label. You are the OP, Original Poster. It can be really confusing. If you have a package of medicine that says or you were told to mix 200--400 mg of it into one gallon of water, and your question was how to measure that, 1/10 - 1/8 tsp per gal is proper dosage. You're good to go. If not, as @ChickensAreSweet said "You will have to check the label and see how much powder they have said equals the 200-400 mg. This must be defined before we can help you". The mg will not tell you how much of the powder to use. It can be tricky to convert.

 

[Eggcessive]

oxytetracycline

If the brand of oxytetracycline is the one below, the manufacturer says that the dosage is 2 1/2 tablespoonsful of powder per gallon of water. Treat for 7 days. There are other brands of oxytetracycline that may have different instructions. I'm not trying to debate anyone on this thread about who is right, but just trying to give the OP some answers with proof to back it up. The dosage information is in this link: http://www.durvet.com/dl/Durvet-Poultry-Brochure.pdf

 

[Mutt Farm]

I wasn't able to explain very well. I read your question as how to measure mg by weight if you don't have a scale. I don't think that's what you needed to know. I found this link that talks about lots of different meds and dosages and measurements. It'll be way more helpful than I was! https://www.backyardchickens.com/t/...-is-400-mg-in-a-teaspoon-chick-meds-please/10