I suck at Math. Man, I really suck at Math.

And I need help with it! What a suprise

I am administering a med to a pet. The dosage is 0.25mg/gram and he is 5 grams, so that is 1.25 miligrams of the medicine. I have a eyedropper with ML listings on it. How would I get 1.25 milligrams to milliliters?

Thanks for your time to help me.