2020 updates by Cathy Bickel
Most medicine prescribed for gerbils will be in oral form to be given with a syringe.
To dose your gerbil, first get a solid one-handed grip on him. Place your index finger across the top of his head with its tip pointing toward his nose, and grip him around the shoulders with your thumb on one side and your middle finger on the other. Your ring and pinkie fingers wrap around his belly. Then quickly flip him over, holding him gently but firmly, as pictured.
Put the tip of the syringe in the side of his mouth behind the incisors and squirt the medicine in. If it is a large dose, try to ease it in so that he doesn't choke. Keep your fingers clear of his teeth.
Some vets prefers to "scruff" a gerbil but scruffing is not for the faint-hearted.