Reconstructive surgery refers to a surgical technique whereby a large skin deficit is healed by the use of a skin flap or graft. A skin deficit may the be result of resection of a tumor or because of a traumatic episode such as a road traffic accident or severe burns, where the skin is irrevocably damaged. 

Reconstructive surgery is used when primary closure (simply suturing the wound edges together) is not an option. This is usually because the hole is too large to be closed without applying undue tension the skin, which is likely to lead to wound breakdown. 

Simple reconstructive surgery may be undertaken in first opinion practice, but referral may be required for larger deficits or surgery on tricky sites such as eyelids or lips.

There are many different techniques available, and the surgeon's first task is to decide which technique to use in order to achieve the best outcome for that patient. In the case of a tumor removal, the surgeon will pre-clip up extensive areas of the dog prior to making the first incision, and mark out with permanent marker, where the flaps or grafts will be harvested from. 

For planned surgery such as a lump removal, repair is usually executed as one event under the same anesthetic. This involves the surgeon preparing a healthy tissue bed to receive the graft. This is done by gently scraping the underside of the flap with a scalpel blade, to remove fat and fascia so the graft makes good contact with a healthy blood supply at the recipient site. 

The skin flap is then partially cut out and rotated into the desired location, and then sutured in place. 

Free skin grafts are pieces of skin that are cut out and moved to a new location. These are often 'meshed' using a special tool that cuts fine lines and makes for a mesh effect. This allows the graft to cover a larger area and under less tension, which makes for better healing. 

For victims of trauma that have sustained contamination of the wound, reconstruction is not undertaken until the full extent of tissue die back is known and any secondary infections brought under control. Thus, it's not unusual for reconstructive surgery to be postponed until one to two weeks after the initial trauma. 

The success of reconstructive surgery depends on: 

Careful planning of where the flap is taken from and the best technique to use

Preparing a healthy recipient tissue bed

Making sure the area is free of infection

Correctly matching the graft size to the deficit

Suturing it in place without tension

Immobilizing the area until healing is complete. 

When complex reconstructive surgery is undertaken, it is not unusual for repeat surgery to be needed in order to address lack of healing or wound breakdown. 

Skin flaps and grafts are delicate and good postoperative care is essential. This means pain relief is advisable, so the dog is less inclined to lick or chew. The area should also be protected from licking, by the use of a cone or dressing. 

In addition, the area needs to be kept immobile until a good blood supply is established to the area and healing is complete. Excessive movement of the patient on energetic walks could lead to wound breakdown. Thus, the patient is often required to rest, with the operation site  protected with a dressing. 

Sutures are left in place for 10 to 14 days, and then removed. The full extent of any revisional surgery is often not obvious until this point, at which further surgery may be recommended 

Each reconstructive surgery is different, and therefore no standard fee exists. The procedure is often charged on the basis of the cost of the surgeon's time per hour, plus the anesthetic, dressing, and pain relief required. 

Starting with anesthesia, this varies depending on the size of the dog, with a small dog anesthetic averaging around $65 and a large dog $99 per half hour. 

The surgical cost per hour varies widely depending on the experience of the surgeon, and whether they are in first opinion practice or a specialist. A vet in first opinion practice may charge around $120 per hour, whilst for a specialist, this could be $500-1,000. 

Remember, this may not be a one-off procedure, but may remedial surgery may be necessary further down the line. 

Most constructive surgery can be life-preserving for the dog with an extensive open wound. It can mean the difference between limb amputation or regaining full limb function, or the need for a dog with a large hole on his flank to be euthanised. 

Perhaps eve more than other surgical procedures, success lies in having a good plan in place, followed by a backup plan should surgery not go well. Unfortunately, should the surgery go poorly, there is a real chance the patient will be left worse off should the donor flap die off completely. 

Good cooperation from the dog's owner is essential, since even the most first class surgery will fail if the patient is not cared for properly in the recovery period. 

Prompt checking of any new lump a dog develops, could prevent the need for reconstructive surgery. It is technically less challenging to remove a lump whilst it is small, than to wait and see what happens and end up removing a much larger mass. Thus, vigilance and prompt action are key to preventing the need for reconstructive surgery. 

Equally, the prevention of trauma by keeping a dog on a leash beside roads and teaching a strong recall, are vital tools that mean the difference between a healthy dog or an injured one.