Surgical closure of the incision
For traditional abdominal surgeries, most vets do what is called a 3-layer closure. The first (inner-most) layer is the strength layer. This closure is sutures up the body wall. The second layer is the subcutaneous layer; the connective tissue (and fat) between the body wall and skin. The final layer, the one everyone sees, is the skin closure.
Pets will often lick or chew at the suture line. Some animals just a few times, other animals will be obsessive about it; possibly removing sutures in the process. Cats are particularly adept at removing sutures prematurely (before the recommended 10-14 day time).
It is important to note that many vets bury the sutures with suture material that dissolves, so there are no sutures to remove. Additionally, some vets use surgical skin glue to speed closure and healing. Your vet will give specific post-surgery instructions upon discharge.
What is "normal" for post-surgical healing?
This varies of course, with the suture materials used, the doctor's technique, and the patient. It is very important to keep your pet from licking and chewing and to keep your pet physically quiet (no vigorous activity) while healing during the 10 - 14 days post surgery time. Any redness, painful swelling, and drainage should be mentioned to your veterinarian right away, especially if your pet is listless and not eating.
A lump can be "normal," sometimes
A firm, non-painful swelling under the incision that appears a few days or a week after surgery is fairly common, particularly in cats. This the body's way of working on the sutures, called a suture reaction. Some animals "react", most don't at all. These types of lumps can take several days or weeks to shrink to normal. If you notice a lump, call your veterinarian. They may want to check it out and make note of it.
When a post-surgery lump is not OK
If you see any redness, swelling, pain, or drainage from the incision, or your pet is listless and not eating, this may be serious - call your veterinarian as soon as possible.
Veterinary Q a A: Suture Site Healing
With a photo of a dog's surgery site, submitted by a viewer.