Edema is the visible and palpable accumulation of fluid in tissue. Edema forms secondary to injury or surgery and can delay the body’s ability to repair a bone or soft tissue injury.
Acute or transient edema can compromise a horse’s health over time. Walk through any barn, whether it houses Thoroughbreds, Quarter Horses, show horses, or any breed competing as athletes, and you will see stable bandages — leg wraps applied for protection or therapeutic reasons.
In upper level equine sports, training and exercise are often concentrated into a few hours, followed by stall confinement for the majority of the day. Due to lack of turnout facilities, equine athletes often have limited opportunity for free exercise or grazing and the continuous movement these activities provide.
The necessity of hours confined to a stall can set the stage for circulatory dysfunction in the horse’s limbs, resulting in swelling that can be localized or involve the entire leg. The traditional answer to this problem is to apply leg bandages, the expectation being that they are applied with skill and attention to detail. Unfortunately, this may not always be the case. A bandage applied too tightly can disrupt lower limb circulation resulting in damage to the leg flexor and extensor tendons and produce subcutaneous swelling. An overly tight bandage, one applied with uneven tension or with wrinkles or folds can cause pressure necrosis within as few as 24 hours and lead to damage to the skin and underlying tissues (1).
In contrast, properly applied compression will control filling in the fetlock joint or tendon sheaths of the lower leg when a horse is faced with a long van ride or stall confinement. Properly applied compression to the leg joints (the hock, fetlock, or carpus) controls post-surgical bleeding and provides pain relief.
Lymphedema, also called lymphangitis, is quite painful and depleting to the immune system. It is often triggered by an inflammation, such as a wound or surgery, and may take weeks or months to develop. In horses, it is most often thought to be associated with pastern dermatitis, or dew poison, a common condition that affects horses living or working in wet, muddy conditions. It is often seen during rainy, damp weather or from sweat accumulation in the long hair at the back of the fetlock joint. The skin over the pasterns and heels becomes irritated and infected, often resulting in scabby fluid-filled lesions (2).
The chronic presence of protein-rich lymph fluids is painful and difficult to treat successfully in the horse. Over time this fluid hardens into dense connective tissue that restricts limb range of motion and causes the horse chronic pain. Treatment has traditionally consisted of:
- administration of antibiotics and anti-inflammatory medications
- physical therapy
- hyperbaric chamber treatments
- stem cell therapy
Beneficial results are usually only temporary and the edema inevitably returns when the horse has a change in hormone levels, stress, stall confinement, or a minor injury.
FROM HUMANS TO HORSES
Lymphedema occurs in humans, perhaps more frequently than in horses, and one treatment has shown consistent results in human lymphedema management. The use of specifically designed garments has proven to be the only way to manage chronic lymphedema over the long term and prevent lymphedema from worsening. Using the human experience as a guide, equine compression garments are designed to remove lymph congestion by stimulating the activity of the horse’s lymphatic system. If applied in the early stages of lymphedema, compression garments may eliminate connective tissue fibrosis.
The lymphatic system and blood circulatory system are responsible for maintaining body fluid homeostasis. The lymph vessels drain fluids that have escaped the blood vessels and cells following an injury and carry it back to the venous system. Veins are the blood vessels that carry blood from the extremities to the heart. When the horse is moving and the system is functioning normally, skeletal muscles and the pumping mechanism of the hoof structure aid venous blood movement. When the horse must stand for an extended period, venous blood movement slows and pressure within the veins increases due to the weight of the blood column between the foot and the heart (3).
Because the lymph system is a vital part of the immune system, a vicious cycle is soon set up when infection and inflammation cause edema. Edema leads to increased susceptibility to infection as lymph stasis compromises immune responses. When traditional standing bandages are used, it is not uncommon to see fluid quickly return when the bandages are removed. The imbalance of protein and fluid between the blood and tissue draws fluid back into the tissues when the bandages are removed. Successful compression support is central to managing this condition.
An interesting study compared the influence of traditional bandaging material with elastic compression garments on lymph flow in horse’s legs. Ten horses with a tendency for swollen legs were examined under sedation with lymphangiography. Movement of a continuous subdermal injection of x-ray contrast fluid through the lymph vessels of the horse’s legs was seen to stop with the use of traditional bandages, but maintained normal flow with the elastic compression garments (4).
The use of elastic compression exerts mechanical pressure on the skin surface stimulating circulation, rather than contributing to circulatory stasis. Equine compression garments offer evenly graded compression through fabric woven specifically for vascular support. The medical benefits of this type of elastic compression have been proven in human edema therapeutics. Few medical interventions produce so dramatic an effect for so little expense and effort.
CREATING A BETTER BANDAGE
Until recently, there has been little innovation or new development in the materials used for equine leg bandages. Now technological advances in elastic material and anti-microbial fabric provide an opportunity to create a better leg bandage for the horse. An Ohio-based medical manufacturer with over 100 years experience in human medical compression has come forth with an equine focused division dedicated to development of quality compression garments for horses’ legs. With these new products, the science of medical compression joins the art of bandaging equine limbs.
The braces are characterized by their anatomically perfect fit and precisely defined compression, which contributes to faster drainage of lymphatic fluid and removal of toxins. Breathable fabric combined with optimum compression distribution promotes and supports lymphatic flow as well as blood circulation, resulting in faster recovery from edema in the horse’s legs and playing an important role in fluid balance in the lower limbs. The braces are equipped with zippers to apply quickly and easily without worry of wrapping too tight, too loose, or in the wrong direction. A product option for wound treatment or dermatitis includes antibacterial silver fibers knitted into the fabric, proven to combat bacteria such as staphylococcus aureus.
A properly applied compression leg garment is the single most effective way to control the painful accumulation of fluid.
A growing trend in human sports medicine is the use of compression clothing, worn to reduce fatigue and enhance recovery from exercise. Compression garments have a long history of use in human cases of post-surgical swelling and chronic edema. With the new equine compression garments, horsemen have a more effective and more economical means of lower limb support.
Mimi Porter is the founder of Equine Therapy, Inc., a therapy service business for horses, and www.equinehealthcare.com , a web site for equine therapists.
1. Ruggels AJ and Dyson SJ. Bandaging, Splinting, and Casting. Diagnosis and Management of Lameness in the Horse . Ross and Dyson, eds. Saunders, p769, 2003.
2. Powell H and Affolter VK. Combined decongestive therapy including equine manual lymph drainage to assist management of chronic progressive lymphoedema in draught horses. Equine Veterinary Education . 2012;24:81-89.
3. Reed BV. Peripheral Vascular Effects of Electrical Stimulation. in Dynamics of Human Biological Tissues . Currier & Nelson eds. FA Davis Company. p139, 1992.
4. Fedele C, Brandhorst B, Hecker A, and Von Rotenfeld D. Influence from cotton wool bandages and elastic stockings on lymph flow in horses’ legs. Equine Medicine 2006;22:17-22.