A few years back, a friend in Sunday School introduced me to a phrase she had learned while growing up back home in Arkansas. After visiting a friend who had recently been in the hospital for a serious surgery, she reported that he was doing well and would soon be “healed up and haired over.” Though I had never heard that expression before, it really did make a lot of sense, especially when used in the context of my patients. At our animal hospital in Rock Hill, we see daily how quickly our patients can heal from amazingly complex wounds.
This amazing healing means even more to me now since I recently experienced it first-hand, literally. Three weeks ago I was trimming some brush to create a walking path through the woods using a hand-held machete. Although the day was a hot one and I was tired, things were going well; I had cleared several hundred yards of the trail. Going well, that is, until the tip of the hand-axe caught some vines as I swung, causing the machete to come down across the back of my left hand. The sharp blade instantly severed the skin, along with the prominent veins that run just under the surface. Though the initial bleeding was dramatic, I was miraculously blessed to have not damaged the tendons which control the function of my fingers. Promptly self-administered first-aid and wonderful after-hours treatment at Riverview Medical Center helped the healing process begin, and within a week I was back performing pet surgery at our vet office.
This month I will briefly describe the healing process which we share with our four-legged family members. By understanding how we heal, we can learn how to help the healing process in ourselves and our pets.
Healing actually begins as soon as the injury occurs and the wound begins to bleed, indeed, the blood itself is the first key to healing. Certain components in the blood provide the physical and chemical building blocks for healing. Within minutes after I cut my hand, for instance, the blood platelet cells combined with specific blood clotting proteins to form a barrier to limit further bleeding. Each blood artery and vein has tiny fibers which squeeze the severed blood vessel opening partially closed. Then the blood clotting proteins form a mesh-like cover over the cut, and the platelet cells which are trapped by the mesh are able to “clog” up the wound and stop the bleeding.
Help is sometimes needed to insure that the bleeding stops. In my case, I applied direct pressure on the wound to slow the blood flow while the clotting process was beginning. For our pets, direct pressure is also effective. If your pet cuts its pad when it steps on something sharp, or cuts its side on a wire gate, holding a clean bandage firmly over the wound is the best way to help stop bleeding. Because skin wounds hurt, do be careful as you help your pet so that you are not bitten. Also, with rare exception, do NOT apply a tourniquet around a limb: the risk of cutting off the blood supply is too great. If direct pressure does not allow the clot to form and stop the bleeding, it’s time to call your pet hospital.
For me, the wound needed more help. A large vein on the back of my hand had been severed, and the clotting process alone could not stop the bleeding. That’s where stitches came in. Under a local anesthetic my health care provider clamped and ligated (that’s an expensive word for “tied”) the end of the vein to stop the bleeding, and proceeded to close the skin wound itself with sutures; again, the fancy word for stitches.
Even without sutures, a wound will heal. The same clot which helps stop the flow of blood provides a perfect environment for the body to close the wound. The blood in the clot dries and scabs over, protecting the tissue underneath as it heals. Other blood proteins enter the wound area providing the building blocks for tissue repair, and the nearby tissue cells begin to grow and multiply more rapidly. This rapid growth actually makes the wound physically smaller, speeding up the healing. The blood vessels dilate to bring more oxygen and energy for the healing process (this, by the way, is why the area around a healing wound is often a bit red.) The proteins which helped the clot form are then incorporated into a very strong fibrous tissue which begins to permanently bond the wound together. When treated properly and without complications, a skin wound can heal in as little as 7 days.
To minimize the scar formation, helping the wound to look better but more importantly also allowing the tissue to function more properly, sutures can be placed which restore the wound edges to their original position. The smaller the space between the wound edges the smaller the scar. There are many different types of sutures for different situations. For internal use, sutures made of organic or synthetic materials which are gradually absorbed are helpful. The body’s immune system slowly dissolves the suture material as the tissue heals…remaining secure until the fibrous scar tissue has enough strength to take the stress of tissue movement.
Other than the absorbable sutures which ligated the severed vein, my injury did not require further internal sutures because it was a shallow wound- thank goodness, because if it were any deeper it would have damaged the tendons under the skin.
The skin did need to be sutured to close the wound, and for this type of procedure, sutures that do not dissolve (“non-absorbable” sutures) are generally used. Skin sutures can be physically removed when the healing has progressed, so it is not necessary for the sutures to dissolve on their own. This is good, because since non-absorbable sutures do not stimulate as dramatic an immune system response the skin remains less inflamed…less redness, less swelling, and importantly for me and for my patients, less itchiness.
As we provide pet surgery services at our veterinary practice in Rock Hill, we do our best to help make the suture site as painless and comfortable as possible, and non-absorbable skin sutures can be a big help.
Sometimes we also close wounds using synthetic liquid sutures instead of suture thread. This surgical adhesive is actually a refined sterile form of Cyanoacrylate, commonly called “super-glue.” When a thin film of this surgical adhesive is placed on the skin as the wound edges are held together, a rapid bond forms which can instantly hold the stress of movable tissues. The adhesive gradually flakes away as the tissue is healing and requires no recheck for suture removal. Surgical staples made of stainless steel can also be used in the skin. They have the advantage of being able to be placed rapidly and they do not stimulate a dramatic immune system response.
Whether sutured or not, a wound can heal quickly as long as it is left alone. By this I mean that the healing mechanisms are amazingly efficient, but they can be negatively affected by infection or movement. The initial scar tissue that forms has a rich blood supply and is very resistant to infection, but within hours bacteria can contaminate a wound, especially if there are pockets of fluid or loose tissue left under the skin. If they do get a foothold, the bacteria can take advantage of the injured tissue and interfere with the healing process. If an injury or surgical wound becomes infected, the immune system reaction is much more severe, resulting in redness, swelling, and pain. Antibiotics are often needed, but cleaning the wound, draining or eliminating any pockets of fluid, and trimming away any unhealthy tissue before suturing or bandaging are even more important than pet medicine.
My wound did not become infected; it was a clean cut (I had sharpened the blade just before using it!), I had cleaned it well following the injury, and it was professionally treated within a short period of time. All of those same principles are appropriate for our pets. Gentle cleaning of shallow wounds with soap and water and prompt attention by your veterinarian can help prevent an infection from occurring.
Excessive movement can also slow healing. It is more difficult for the tissues to bond and heal when they are being stressed and moved. Wound movement can be minimized by proper bandaging and by limiting activity. We sometimes have to recommend confinement to help insure that the wound area receives proper rest.
Pets sometimes slow the healing of their wounds by excessive licking or chewing at the injury site. Interestingly, a certain amount of licking has its place in wound healing – by licking away bacteria and small “bits” of unhealthy tissue or pus a pet actually can help keep the wound clean – but there is a limit. Excessive licking and chewing can enlarge a wound and even damage healthy underlying structures, so we have to stop that behavior on occasion by using an Elizabethan collar. Also known as the dreaded “lampshade,” “bucket,” or “cone of shame,” there are several types of these restraint collars which, although awkward and used only when necessary, can play a very important role in the healing process. (Fortunately, I did not require an E-collar for my own injury, although I did have to resist the urge to scratch at the stitches as my wound was healing.)
Even after a skin wound has technically healed, it may take a few more weeks for hair to regrow over the area. (Interestingly, on rare occasions we will see the hair grow back as a different color…why we don’t really know… and sometimes this color change is permanent.)
The entire healing process, for me and for our pets, still fascinates me. Just three weeks after a serious skin wound I have “healed up.” As I look at my scalp in the mirror, though, I see that any thoughts I have of becoming “haired over” again are probably misplaced.