Same dose for all ages, and sometimes I give it orally too.
In addition to medicated water:
9.6% liquid - Do not dilute
Give 0.1 ml per pound of body weight orally once or twice a day for 1-3 days.
or
0.02 ml per 100 grams of body weight orally once or twice a day for 1-3 days.
20% powder...
If the vet said 575 mg per liter, that is 6 ml per liter, that is 22.71 ml per gallon.
Math:
6 ml /1000 ml (# of ml per liter) = 0.006 Corid per 1 ml water
3785 (# of ml per gallon) x 0.006 ml = 22.71 ml of Corid per gallon.
Use 10 ml per gallon,
Treatment
20% Powder
9.6% Liquid
For 3-5 days
1.5 teaspoons per gallon
2 teaspoons per gallon
then for 7-14 days
1/3 teaspoon per gallon
1/2 teaspoon per gallon
One gallon of Corid makes 378.5 gallons
One 10 ounce pack of Corid makes 62.5 gallons.
To make one gallon of the 9.6% solutions you need ~6 packs of powder.
So I just did the math and one 10 ounce package will make 62.5 gallons of the severe infection rate (0.024%), or 125 gallons moderate infection rate (0.012%). I always suggest using the severe infection amount for 3-5 days.