The 1/2 teaspoon Corid Powder dose keeps rearing is head, so I thought I'd do another thread that shows why it's incorrect.

• First we need to know that the Corid sold in the US is labeled for cattle, not poultry, so that means the directions on the bag and bottle are for cattle. Labeled for cattle doesn't mean that we can't use in on other species, but that we need to figure out the proper dosing for other species.

• Second, there are at least two other products sold in the US that *are* labeled for poultry. One is Amprol 128, the other is AmproMed. All three are exactly the same, so  the same dose applies to all 20% products when treating poultry.

• 20% means that there are 200 mg per gram.

• One ounce of these powders = 3.5 tablespoons.

Here are the mixing instructions for Amprol 128:

The AmproMed instructions are the same:

Now what? Now you have to decide if you want to treat for a moderate or severe outbreak, and I think you will find that most people on BYC choose to treat for the severe outbreak, which means the 0.024% level.

8 ounces of powder is 226.796185 grams. So it's 226.796185 grams ÷ 50 gallons = 4.5359237 grams per gallon. 4.5359237 x 200 mg = 907.18474 mg per gallon.

One ounce of these powders = 3.5 tablespoons.

One ounce = 28.3495 grams

3.5 tablespoons = 10.5 teaspoons

28.3495 grams x 200 mg ÷ 10.5 tsp = ~540 mg per tsp.

Desired .024% dose is 907.18474 mg per gallon, so it's 907.18474 / 540 = ~1.68 teaspoons per gallon

Here's the kicker... math shows that one teaspoon should weigh about 2.7 grams, but when I weighed it, it was much closer to 3 grams, so 3 grams x 200 mg x 1.5 tsp = 900mg, which is close enough to the target of 907 mg.

Hope this wasn't too confusing, and as usual, please check my math.

So what all of the above shows is that the correct dose to treat a severe outbreak is absolutely no less than 1.5 teaspoons per gallon and probably not more than 1.75 teaspoons per gallon.

-Kathy

Edited by casportpony - 12/1/15 at 9:58am