Prepare the Dose
You will need to prepare a shot in order for the insulin to be administered. Take out the insulin from the refrigerator and run the vial in between your palms. This will slightly increase the temperature of the vial, thus making the shot less painful for the dog.
Take an insulin needle and remove the needle guard off of it. Bring the insulin vial nto vertical position such that the rubber stopper is towards the ground. Keeping the vial in this position, penetrate it through the stopper with the insulin needle.
Push the plunger to force out all the air in the needle. Draw a small quantity of insulin into the needle and then empty it by pushing the plunger back in. Repeating this step twice would ensure that the inside walls of the needle are coated with insulin and no air remains inside the syringe.
Draw up the required prescribed quantity of insulin into the insulin needle and then slightly thump the syringe to ensure removal of air bubbles that might have formed while you were extracting insulin from the vial.
Reattach the needle guard that you had removed earlier and return insulin remaining in the vial back to the refrigerator.
Administer the Insulin
Sit on the floor next to your dog in a position where you would not face any difficulty while administering the dose of insulin.
Get rid of the needle guard and firmly hold the dose in your dominant hand.
Gently squeeze and then separate a fold of the dog's skin away from its body. With the other hand, inject the needle, through the base of the folded skin and inject the insulin by pressing the plunger with your thumb.
Finally, dispose of the used needle in a proper manner.