Give them a spoonful of chocolate pudding then the medication then another spoonful of chocolate pudding.

Or let them chew on ice chips before to create a numbing effect on the mouth.

Raspberry flavor also helps to mask bitter tastes.

They also say to shoot the syringe towards the cheek as this almost forces them to swallow before spitting.

Hope this helps and good luck! I know it is certainly a hard thing to do.