As every horse owner knows, lacerations and traumatic injuries are not uncommon in horses, particularly involving the lower limbs. These are usually related to mishaps with fences, gates or wire. Wounds on the lower limb – below the knee or hock – are always a potential problem. This is due to the unique anatomy of this region. There is very little soft tissue or muscle between the skin and underlying tendons and bones, combined with very little skin mobility. These factors mean that wounds cannot contract well, and blood supply is poor. It is important if functional and cosmetic healing is to be achieved, that appropriate and aggressive initial treatment of these injuries is carried out.
The time between the wound occurring and primary treatment is critical – the so-called “golden hour” - so please do not hesitate in calling your vet if you feel that an injury is serious enough to warrant veterinary intervention. After about four to six hours, primary suturing of a wound in a horse is far less likely to be successful.
Bleeding should be controlled by applying direct pressure to the wound and keeping the horse as quiet as possible. Arterial bleeding can be fairly impressive and it is important to stay calm. A pressure bandage can be fashioned out of a wad of gamgee, held on to the limb with crepe or vetwrap bandage. Do not apply cotton wool directly to the wound, as the fibres, which adhere to the exposed tissue, will delay wound healing. If the bleeding continues through the bandage, do not remove it, but place another over the top. Using digital pressure on the skin directly above a bleeding superficial artery will often help stem the blood flow. Where absolutely necessary, a tourniquet can be placed above the laceration while the pressure bandage is applied. Never leave a tourniquet on for more than a few minutes.
Lavage (flushing) of any contaminated wound is very important, as this markedly reduces the bacterial load in the wound, hence reducing the chance of infection. Furthermore, thorough lavage will remove any organic or inorganic debris present in the wound, allowing the healing process to proceed rapidly. Wound powders or pepper should be avoided at all costs, as the particles act as a foreign body and will greatly delay healing.
We usually use an isotonic sterile saline solution for wound lavage, but where a delay in veterinary assistance is unavoidable, a saline solution can be made up. Using boiled water, which has been allowed to cool, dissolve one heaped teaspoon of salt per litre of water. The easiest and most effective method of flushing a wound is to use a large syringe. The volume of liquid used is the most important factor, at least one litre, and preferable two or three litres, depending on the extent of the injury.
Depending on the nature, location and size of the wound, we may suture the wound. Often this will involve sedation and the use of local anaesthetic. A degree of surgical debridement (trimming) of non-viable tissue may be necessary, and where large flaps of skin are encountered, surgical drains may be placed.
Bandaging following primary wound care is important for a number of reasons:
- Protection of the wound from further contamination
- Tissue support and wound immobilisation, reducing soft tissue trauma
- Control of bleeding
- Prevention of tissue swelling
- Absorption of exudate, and provision of drainage
- Reduce risk of proud flesh
Bandages should be checked regularly. Any sudden increase in lameness, swelling above the bandage or coolness of the limb below may all be indicative of a problem, and the bandage should be removed and replaced.
Where suturing of a wound is not feasible, wounds are left to heal by granulation or “second intention” healing. Proper debridement and flushing of these wounds is no less important, and bandaging in the early stages of healing is highly beneficial.
Where exudation is present, use of petroleum jelly on the surrounding skin, especially below the wound, will protect the healthy skin.
Tetanus prophylaxis is advisable with all open wounds in horses, due to their susceptibility to this disease. Antibiotics may also be prescribed.
Proud flesh is seldom a problem where lower leg wounds are correctly handled, but in occasional cases may occur despite the best treatment. Proud flesh is excessive granulation tissue, which, once raised higher than the skin edges, prevents wound contraction and continued healing. Various topical preparations are available for management of proud flesh, although surgical excision to below the wound edges is the most effective method of dealing with this problem.
Skin grafting is sometimes used in cases where a large area of scar tissue remains once wound contracture and healing have occurred.
Tiny pieces of skin are sourced from elsewhere on the horse, usually behind the girth, and implanted into the prepared wound bed. This tissue provides skin cells that spread out and cover the defect.
Wounds near synovial structures (joints and tendon sheaths) can be disastrous if not recognised ASAP. Joint and tendon sheath infections need special attention, with aggressive treatment and often referral to a hospital; a joint infection left for a few days may end a horse’s career.
If faced with a wound, play it safe – get it checked out by one of our vets as soon as possible.