The incision is usually very small and the closure is in two or three steps. The first closure brings the skin edges together, and the second layer closes the subcutaneous level. This way, there aren't any sutures visible (or lickable) on the outside skin surface. Some vets use surgical glue for a third level of closure.
Some veterinarians use non-dissolvable sutures that will need to be removed in 10-14 days. In cases of a very active dog or one known to lick, sometimes wire sutures are used - they add strength and the prickliness discourages licking. They also need to be removed in 10-14 days.