Dosage Conversions

Although the information below is written related to medication for Cattle, the conversion
information is the same for your goats.

Cattle and drugs are, according to this story, both too expensive to take a chance
on miscalculating dosages just because the label writers think every cowboy is some
sort of math-matics whiz. At best, an overdose is a waste of money. Often it also
does more harm than good, and underdosing is not much better. With dosages, little
mistakes in arithmetic can have big consequences. This story explained that pharmaceutical
calculations can be confusing because they employ the metric system as well as standard
U.S. weights and measures. So the cowboy who thinks in pounds and ounces winds up
trying to dose so many cc's or mg's to a kg. Conversion factors serve as bridges
between the two.

Example: You've got a 385-lb. calf and need to dose him at 1.5 mg/kg. To determine
the kilogram weight, divide 385 by 2.2. He weighs 175 kg. Then multiply 1.5 mg times
his 175 kg weight, so he needs 263 mg. The drug is labeled with a concentration of
50 mg/ml, so you'd divide 263 by 50 and come up with 5.25 ml. That's the dose to
administer. If there is a question about a conversion factor, or you are unsure of
your final answer, always call a veterinarian or pharmacist to ask, or have someone
double-check your answer.

This story warns to be cautious of losing decimal points in calculations. If, for
example, the correctly calculated dose to give an animal is 5.5 ml a decimal point
mistake can lead to answers like 55 ml or 0.55 ml. When writing dosage calculations,
be aware of significant digits such as leading decimals and zeros. For example, always
write dosages of 0.5 ml with the preceding zero, otherwise the decimal in front of
the 5 can get lost or not copy well from carbons or photocopies and can be construed
as 5 ml. Likewise, always drop insignificant zeros. For example, 30 ml should never
be written as 30.0 ml. The decimal point can get overlooked and the dose will incorrectly
look like 300 ml.