Hi Sandy, I am not a expert on the syringe variations especially with a insulin syringe or why to use a insulin syringe but just reading what you said it sounds like he rounded up to 10 (with the 2.2) I am not sure how he got to .3 on a U100 but I am sure many vets will use different measures. Maybe he was rounding up to make it easier as well....those lines are teeny!

I will only speak to my own experience (which includes many pets who come to my shop for the shot because owners are afraid to give a shot

)
How is Shoes doing??