Looking for ways to reduce swelling in your horse’s legs? Several factors can lead to leg swelling in horses, ranging from mild conditions such as “stocking up” to more severe issues such as cellulitis.

If your horse is experiencing limb swelling, your first priority should be consulting with your veterinarian to identify and treat the underlying cause. Then, you can implement several management techniques to reduce the swelling.

Swelling can affect any part of the horse’s leg but is most common in the lower limbs. Swelling may also occur around joints such as the knee or the hock, and, in rare cases, can also affect the upper limb.

Cold therapy, leg wraps, massage, anti-inflammatory medications, and sweat bandages are just some of the strategies used to address leg swelling in horses. Regular exercise, good stall hygiene, and avoiding prolonged periods of inactivity can also help prevent swelling.

Common Causes of Limb Swelling in Horses

Swelling in a horse’s leg is the accumulation of excess fluid in the tissues or joints. If the swelling occurs outside of a joint, it is referred to as edema. When swelling happens inside a joint because of increased fluid within the joint capsule, it is known as effusion.

Limb swelling in horses can be caused by a variety of factors and conditions, including inflammation, injury, infection, poor circulation, immune responses, or other underlying health conditions.

Some of the most common causes of limb swelling in horses are detailed below:

Stocking Up (Stagnation Edema)

Stocking up refers to swelling that develops in the lower legs due to inactivity, usually when a horse is stalled for long periods of time. Stocking up typically affects the hind limbs, but occasionally affects the forelimbs as well. [1]

This condition arises when a horse’s circulatory system becomes less efficient due to reduced movement, leading to fluid accumulation in the legs. [1]

Stocking up does not appear to be painful for horses, but it may lead to mild stiffness and reluctance to move. Affected horses generally do not suffer other adverse effects and the condition is easily resolved with light activity in most cases.

Trauma

Any type of trauma to the leg can lead to acute swelling, including contusions (bruises) from impact, abrasions from rough surfaces, puncture wounds from stepping on sharp objects, or overexertion injuries from intense exercise or jumping.

If a laceration (skin wound) is present or indications of a bite wound, such as a snake bite, consult your veterinarian. Immediate treatment may be required to prevent an infection.

Allergic Reaction

Horses can also experience limb swelling as a result of an allergic reaction to environmental factors, such as insect bites, plant allergens, or chemicals found in bedding or grooming products.

A common allergic reaction in horses is Type 1 photosensitization (photodermatitis). In this condition, photosensitive substances accumulate in the skin and react with sunlight, resulting in inflammation and painful skin swelling. [2]

Photosensitization is most common in horses with unpigmented or lightly colored areas of skin. Plants that can trigger a photosensitive reaction include:

  • St. John’s wort
  • Bishop’s weed
  • Clover
  • Buckwheat

In some cases, photosensitization may be triggered by alfalfa hay. [2]

Horses can also develop Type II photosensitization, which occurs due to liver damage. This condition can also lead to swelling and dermatitis of the lower limb(s). If this condition is suspected, consult your veterinarian right away. [2]

Bowed Tendon

A bowed tendon is a condition in horses that involves the tearing of the superficial digital flexor tendon in the middle of the cannon bone area. This injury is characterized by a bow-like swelling on the back of the leg, extending from the knee down to the fetlock. [3]

A bowed tendon will lead to acute swelling, heat, and pain. The horse may or may not show lameness. Ultrasonographic evaluation by your veterinarian can determine the severity of the tendon damage. [3]

Bowed tendons are a serious injury and can take a long time to heal. Horses typically need stall rest and restricted exercise for at least two months and possibly up to eight months, depending on the severity of the injury. [3]

However, most horses can recover and return to athletic performance if the injury is given enough time to properly heal. [3]

Ligament Injuries

Horses can also sustain ligament injuries, such as strains or damage resulting from trauma or overuse, which can cause swelling in the lower leg. A horse suffering from a ligament injury can exhibit mild to severe lameness with heat and pain present in the affected area. [4]

An example of a common ligament injury in horses is bucked shins or splints. This injury is caused by strain placed on the ligament between the cannon bone and splint bones. [5]

As a horse ages, this ligament naturally ossifies. Jumping, running, and/or hard work can irritate the area, leading to pain. [5]

Splints usually affect the inside part of the foreleg and can result in lameness and swelling. This condition often occurs in young horses in hard training, between the ages of 2 to 5. After the ligament has fully ossified, the swelling and soreness usually disappear. [5]

Windpuffs

Windpuffs are soft, fluid-filled swellings of the fetlock region usually caused by excessive strain. They can occur in both the front and back legs.

Windpuffs generally do not cause pain or lameness unless there is damage to the underlying tendon sheath.

Pastern Dermatitis

Pastern dermatitis is a skin condition often seen in horses with white legs and in many draft breeds. It arises from multiple causes such as bacterial, fungal, or mite infestations, leading to swelling and discomfort in the lower leg. [6]

Pastern dermatitis is more common in the hind legs and can give rise to secondary infections requiring medical intervention. [6]

Cellulitis

Cellulitis is a serious infection of the subcutaneous tissue of the horse’s leg. This condition typically affects just one leg and often arises as a secondary complication following a wound or the spread of a bacterial infection from another part of the body. [7]

Cellulitis in horses involves considerable swelling and severe lameness. The condition is considered a medical emergency and often develops rapidly. The affected leg may be warm and painful to the touch and the horse may also have a fever and be lethargic. [7]

If the condition is not promptly addressed, it can rapidly progress, leading to the leg swelling to 2-3 times its normal size. This condition also poses a serious health risk and can be life-threatening. The primary treatment for cellulitis involves the use of antimicrobial therapy. [7]

Lymphangitis

Lymphangitis (big leg disease) is a severe condition characterized by swelling in the lower limbs, disrupting normal fluid circulation and leading to fluid leakage into the surrounding tissues. This results in extreme swelling in one hind leg, accompanied by significant pain and fever. [1]

Horses affected by lymphangitis often exhibit clear signs of depression. Some horses show signs of trembling, rapid breathing, and/or sweating. [1]

Lymphangitis is caused by a bacterial or fungal infection, typically associated with a wound to the leg. Pathogens identified in cases of lymphangitis include Staphylococcus, Streptococcus, or E. coli species.

The bacteria reproduce quickly in the lymphatic system, leading to an inflammatory reaction. The lymph nodes can get overwhelmed and become infected as well. [2]

Chronic Progressive Lymphedema

Chronic progressive lymphedema (CPL) is another condition that results in swelling of the lower leg. CPL is most common in draft breeds but can affect non-draft breeds as well.

Secondary bacterial and parasitic infections can complicate CPL lesions and worsen symptoms. [8][9]

Other Causes of Limb Swelling

Leg swelling in horses can also be caused by other conditions including:

  • Lung disease
  • Purpura Haemorrhagica (a complication of strangles)
  • Kidney disease
  • Liver disease
  • Heart failure
  • Thyroid disease
  • Damaged blood vessels or nerves

These conditions are considerably less common. If the horse is otherwise in good health, the limb swelling is likely attributable to a less severe issue.

9 Ways to Reduce Swelling in Your Horse’s Legs

The best way to reduce swelling in your horse’s legs depends on what is causing the swelling in the first place. Prompt diagnosis and treatment of any underlying infections or conditions is important to prevent secondary complications.

Consult with your veterinarian to determine the best treatment plan depending on your horse’s individual status. Once you have addressed any underlying health concerns, there are a number of tried-and-true ways to reduce generalized swelling in the horse’s limbs.

1) Cold Water Therapy

Cold water therapy involves hosing the affected leg with cold water for 10 – 20 minutes, usually two to three times a day or as needed.

Applying cold water to swollen tissues helps to reduce heat and inflammation in the leg, as well as improves circulation. Cold water therapy can be especially beneficial for horses affected by stocking up, tendon or ligament injuries, or trauma to the leg. [4]

An increasingly popular alternative for treating leg swelling is the use of an equine spa, which offers a controlled cold water immersion therapy. [4]

2) Ice Therapy

Ice therapy (also known as cryotherapy) is another strategy to reduce swelling in the legs by applying ice boots or wraps directly to the affected areas. Cryotherapy can also be conducted by placing the horse’s limb in a bucket of ice water.

This method helps to constrict blood vessels, reducing blood flow to the swollen tissues, which can significantly decrease inflammation and pain. Ice therapy works best for tendon and ligament injuries or other trauma to the leg.

Is it recommended to apply ice therapy for 20-30 minute sessions, between two to three times daily, depending on the need.

Incorporating compression can enhance the benefits of ice therapy. This can be achieved using a commercial dry sleeve cryotherapy system. [10]

3) Standing Leg Wraps

When used correctly, leg wraps or bandages provide beneficial compression, helping to move excess fluid from the soft tissues back into the lymphatic system and bloodstream.

If using any kind of leg wrap, make sure not to wrap the legs too tightly, which could hinder blood flow. Additionally, don’t leave bandages on for too long as this could restrict circulation to the lower limb and hoof.

4) Sweat Bandages

Sweat bandages are slightly different than standing leg wraps. When using a sweat bandage, a topical substance or poultice is initially applied to the leg, which is then covered with a layer of lightweight plastic, followed by a bandage. [11]

The topical substance is meant to help draw swelling from the leg. Common ingredients used in a sweat bandage include: [12]

  • DMSO (dimethylsulfoxide)
  • Mineral Oil
  • Petroleum Jelly
  • Epsom Salts
  • Glycerin or Glycerol

Sweat bandages must be applied correctly to be effective and avoid cutting off circulation. Do not leave a sweat bandage on for more than 12 hours. Allow the leg to remain unwrapped for 12 hours between uses and then reapply if necessary. [11]

5) Clay Poultices

Clay poultices are one option to use in conjunction with a sweat bandage. Clay has been used in traditional medicine since ancient times and is believed to have several therapeutic properties that may aid in the reduction of swelling. [12]

Clay poultices can be purchased as a ready-made formulation, or you can use dry clay powder (such as bentonite clay) mixed with water to make a paste that can be applied to the horse’s leg.

6) Gentle Movement

For minor conditions such as stocking up light exercise or gentle movement can help to reduce swelling by increasing circulation and lymph drainage.

Controlled exercise is an important part of rehabilitating horses with tendon and ligament injuries. Gentle movement helps to alleviate inflammation and promote collagen remodeling.

Before implementing any exercise, horses with these types of injury should first be evaluated by a veterinarian and placed on stall rest for 10-14 days. [4]

7) Massage

For leg swelling caused by stagnant lymph fluid, massaging the lower legs can be beneficial. Research shows that massage increases skin temperature and enhances blood flow in local regions. [13]

8) Medication

Corticosteroids and non-steroidal anti-inflammatories (NSAIDs) are two types of medication often used to reduce inflammation in horses due to conditions such as tendon and ligament injuries. [4][14]

Consult with your veterinarian prior to administering any medication to your horse. They can guide you on the most suitable medications for your horse’s condition and provide instructions on their safe administration.

Corticosteroids can be administered during the initial inflammatory phase of an injury, typically within the first 24-48 hours. However, long-term use should be avoided because they can inhibit tissue healing. [4]

Examples of NSAIDs commonly used to reduce swelling include:

Bute, or phenylbutazone, is frequently prescribed although, studies suggest it has a stronger pain-relieving effect than an anti-inflammatory one. [3][4]

Similar to corticosteroids, most NSAIDs should only be used for short periods of time to alleviate swelling and pain. [#] Long-term reliance on NSAIDs is discouraged due to potential risks of gastrointestinal or kidney issues.

9) Rest

In cases of severe limb injuries, adequate rest can be the most important treatment for reducing swelling. This is particularly true for tendon or ligament injuries, where limiting movement is essential to provide the damaged tissues ample time to repair and recover. [3][4]

Summary

  • Consult with a veterinarian to determine the underlying cause of leg swelling in your horse. Causes can range from mild conditions such as stocking up to more severe issues such as cellulitis or lymphangitis.
  • Various strategies can be employed to address leg swelling, including cold therapy, compression wraps, massage, and anti-inflammatory medications.
  • Regular exercise and avoiding prolonged inactivity can help prevent leg swelling. In more severe cases, like tendon or ligament injuries, controlled exercise after a period of rest is vital for rehabilitation.
  • Medications such as corticosteroids and NSAIDs can be effective in the early stages of inflammation but should be used with caution and under veterinary guidance due to potential side effects.

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References

  1. Keckler, K. Lymphangitis: A Frustrating Condition. AAEP. 2022.
  2. Puschner, B. et al. Alfalfa hay induced primary photosensitization in horses. The Veterinary Journal. 2016.
  3. Lewis, M.L. Healing the Bowed Tendon. AAEP.
  4. Smith, R.K.W. Tendon and Ligament Injury. AAEP. 2008.
  5. Loch, W. Splints in Horses. University of Missouri. 2003.
  6. Akucewich, L.H. and Yu, A.A. Equine Pastern Dermatitis. Compendium: Equine Edition. 2007.
  7. Hughes, L. Understanding Equine Cellulitis. New England Equine Medical & Surgical Center.
  8. Affolter, V.K. Chronic Progressive Lymphedema in Draft Horses. Vet Clin North Am Equine Pract. 2013.
  9. Powell, H. Therapy for horses with chronic progressive lymphoedema. Vet Record. 2009.
  10. Jacobs, C.C. et al. Efficacy of a commercial dry sleeve cryotherapy system for cooling the equine metacarpus. Vet Surg. 2022.
  11. Applying Sweat Bandages To The Horse’s Leg. AAEP.
  12. Bastos, C.M. et al. Assessment of Clayey Peloid Formulations Prior to Clinical Use in Equine Rehabilitation. Intern J Environ Res Public Health. 2020.
  13. Hidetoshi, M. et al. Effect of massage on blood flow and muscle fatigue following isometric lumbar exercise. Med Sci Monit. 2004.
  14. McCoy, A. Splints and bucked shins in horses. University of Minnesota Extension. 2021.