Step 4: With the puppy's mouth open, insert the end of the tube into the groove formed by the top of the tongue. Carefully push the tube back into the pharynx. You have to push the tube straight in until it reaches the depth of the pre-determined mark. If it does not go down smoothly to the depth of the mark, it is not where it should be. If the tube is accidentally inserted into the trachea, healthy puppies will cough and struggle violently. In addition, a tube that is inserted into the trachea will usually stop about half-way to the mark where it encounters the division of the trachea. Once the tube is successfully inserted to the depth of the mark, slip your thumb and forefinger from the cheeks to the tube, and hold it firmly in the mouth at the level of the mark. Slide your other fingers up and around the puppy's head, leaving the little finger behind the front legs to give it a steady hold.

Step 5: While the tube is held firmly in place, stick the open end of the tube into a small jar of water. If a series of bubbles are produced in the water, it is likely an indication that the tube has slipped into the trachea. It may also indicate that the puppy has a little gas in his stomach. In any case, however, the tube should be removed and blown clear of water, then reinserted until no air bubbles appear in the water.

Step 6: Once the tube is safely inserted in the stomach, continue to hold the tube firmly in the puppy's mouth with the thumb and forefinger. With the other hand, place the open end of the tube between the forefinger and middle finger of the hand that holds the tube in the puppy's mouth. Once again, with the opposite hand, pick up the previously filled syringe and insert it snugly into the open end of the tube.

Step 7: With the syringe firmly attached, apply gentle pressure with the thumb to the syringe plunger and deliver the substitute mother's milk. Continue to deliver the food until the correct amount has been administered. Then, draw back slightly on the plunger and gently slip the tube out, still attached to the syringe.