Lumpy Legs: Common Conditions Affecting the Equine Limb

Very few sports horses are lucky enough to make it through their careers without experiencing some degree of lameness, and even leisure horses and ponies are likely to become unsound at some point during their lives. This is due to the fragile nature of the equine leg, which must support a large amount of body weight with minimal muscle below the knee joint. Unlike humans, horses have no muscle from the knee down, resulting in increased pressure on ligaments and tendons, and poorer circulation when standing still, which can delay healing.

The causes of lameness are broad and can involve many structures, but several common conditions manifest as lumps or swellings on the legs. While it is always best to consult a vet regarding any lameness, having a basic understanding of these conditions can help horse owners recognise when to seek professional care.

Bursal Enlargements: Soft Swellings Around the Joints

Bursae are fluid-filled sacs that cushion tendons and ligaments where they pass over bones. Injury or strain to these sacs can result in swelling known as bursal enlargements. These may cause initial lameness but often become cosmetic blemishes. Treatment typically involves rest, cold hosing, and massage until the pain resolves.

Windgalls

Windgalls are soft, spongy swellings often found above or beside the fetlock joints. They commonly affect horses exposed to frequent concussion on their legs. While they usually do not cause long-term pain, they can cause lameness during formation and may be considered undesirable in show horses.

Thoroughpin

Thoroughpin is a soft swelling located in front of the point of the hock. The swelling can be moved from side to side, indicating strain to the sheath of the deep digital flexor tendon. Like windgalls, it is mainly a cosmetic issue but should alert owners to underlying strain that warrants monitoring.

Bog Spavin

Bog spavin presents as a soft swelling on the inside front of the hock joint and can be caused by knocks or repetitive work on hard surfaces. It often accompanies joint disease and, although it does not usually cause lameness by itself, it signals potential underlying joint problems requiring veterinary evaluation.

Capped Elbow and Capped Hock

A capped elbow is a soft swelling at the elbow point, often caused by trauma from hard or insufficient bedding, or the horse knocking its elbow with a shoe while lying down. A padded 'sausage boot' can protect the area.

A capped hock is a similar swelling at the point of the hock, sometimes as large as a tennis ball, usually resulting from trauma during travel or poor bedding quality. Both require treatment to prevent infection, which can include veterinary steroid injections or hydrotherapy.

Bony Enlargements: Hard Swellings From Bone Changes

Splints

Splints are bony growths on the splint or cannon bones, usually caused by repeated concussion such as trotting on hard roads or trauma. They may cause initial lameness but often become non-problematic unless they impinge on important structures like the suspensory ligament.

Ringbone

Ringbone is a form of degenerative joint disease affecting either the pastern (high ringbone) or coffin joint (low ringbone). It results from repeated stresses like sharp turns and is common in hunters and performance horses. True ringbone is incurable due to bone growth around the joint, but false ringbone mainly affects ligaments and tends to have a better prognosis.

Bone Spavin

Bone spavin appears as a hard protrusion on the inside of the hock joint caused by strain. It often leads to lameness and may cause the horse to drag its toe. Prompt veterinary assessment is essential for correct diagnosis and treatment.

Filled Legs: Common Fluid Swelling in Stabled Horses

Filled legs describe a cosmetic condition caused by oedema—or fluid accumulation—in the lower legs, typically seen in stabled horses and usually affecting the hind legs in pairs. While filled legs may make the horse appear stiff, they are generally not painful or a cause of lameness and tend to improve with exercise.

If swelling is unilateral or extends above the knee or hock, it likely indicates a more serious condition such as tendon or ligament damage, infection, or lymphangitis and requires immediate veterinary evaluation. Oedema associated with filled legs will pit under finger pressure without causing pain, while hard or hot swelling suggests infection or strain.

Management includes regular turnout for exercise, using bandages at night to support the legs, and reviewing the horse’s diet, especially protein intake, as excessive protein may contribute to the problem. Since swollen legs can also be a sign of serious diseases like liver problems, any doubts should prompt veterinary consultation.

When to Seek Veterinary Care

While many lumps and swellings may be harmless or cosmetic, signs that require immediate veterinary attention include sudden onset of heat, pain, lameness, fever, or single-leg swelling. Conditions such as lymphangitis and cellulitis can rapidly become severe and need prompt treatment. Early diagnosis helps minimise complications and improves recovery chances.

Responsible Horse Ownership and Prevention Tips

• Provide good-quality, clean bedding and adequate protection during transport.
• Ensure regular exercise to promote circulation and reduce fluid buildup.
• Maintain hooves and limb hygiene to prevent injury and infection.
• Monitor any lumps or swellings carefully and consult a vet if they persist or worsen.

Understanding common causes of lumpy legs can help owners respond appropriately and maintain their horse’s soundness and wellbeing throughout its life.

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