CPL (Chronic Progressive Lymphedema) in horses: symptoms and treatment

Big (draft) horse breeds are sensitive to CPL (Chronic progressive lymphedema). This incurable condition is possibly partly genetic and affects the lymphatic system and the elastic function of the skin. Characteristic are the thick folds on the legs of the horse. Read on this page what CPL exactly is and what you can possibly do.

What is CPL?

CPL occurs in the legs of the horse, mainly the lower legs. The lymphatic vessels of horses with CPL no longer function properly because there is too little elastin in the tissues. This causes fluid to accumulate in the lower legs, making the legs swollen and the characteristic folds appear. Research has shown that the fluid not only accumulates, but also that the flow of blood and fluid is much slower. Desmosine (amino acid) is responsible for the elasticity of the fibers. Horses that get CPL often have a low amount of desmosine, but over the years there is a lot of desmosine. This changes the elastin network and becomes abnormal, allowing lymph fluid to spread more and more in the leg.

CPL is incurable, the only thing you as an owner can do is treat the symptoms.

Symptoms of CPL

CPL can be recognized by the characteristic folds on the lower legs of horses. Often at a young age of the horse (under 2 years old) it can already be seen that the horse has CPL, then usually the first wrinkle in the fetlock appears. CPL often starts low on the leg (below the fetlock) with flakes, wounds, a fold and fluid in the legs. It is often difficult to see these first signs because the horses have a lot of feathering. The older the horse gets, the worse the folds become. The folds create breeding grounds between the skin folds where fungi, bacteria, and/or mites can thrive. This causes itching, which makes the horse stomp and rub, leading to more wounds that cause further irritation. Symptoms are often worse on the hind legs than on the front legs.

The prolonged edema (fluid retention) makes the skin increasingly thicker and firmer. This can lead to wounds in the long run and can even cause pain and lameness. If CPL gets out of hand, serious painful deformities, a proliferation of bumps, and bacterial infections can occur. In the summer, there may even be maggots between the folds in horses with CPL. Therefore, check your horse's lower legs weekly.

Treatment of CPL

Since CPL is incurable, you can only treat the symptoms and try to slow down the CPL. The following points are important for CPL

• Watch the diet: The feed of a horse with CPL should be low in sugar and starch.

• Wound treatment: Wounds between the folds can easily occur and become infected. It is therefore advisable to completely shave the socks so that the legs can be properly treated.

• Prevent mites: Horses with CPL are more prone to mites. Mites thrive well in the stifling climate between the folds. Prevention is better than cure, so regularly perform preventive mite treatment. Preferably based on natural ingredients.

• Stimulate fluid drainage: Certain herbs can stimulate fluid drainage (such as cleavers and nettle) which can reduce the accumulation of fluid in the legs. But a lymphatic drainage treatment can also help with this.

• Exercise: Of course, being able to move a lot is a must for a horse with CPL, as movement stimulates fluid drainage capacity and improves circulation. Being in a paddock paradise-like setting 24/7 is perfect for horses with CPL.

• Improve circulation: By stimulating circulation, you also stimulate the removal of excess fluid.

Heredity the cause of CPL in horses

The exact cause of CPL is not yet completely clear. Malfunctioning lymphatic vessels and an abnormal elastin content in the skin play a role. It is also expected that heredity plays a role. Unfortunately, there is no genetic test available for CPL that shows whether CPL is hereditary. This suspicion exists because certain bloodlines are more affected than others. CPL mainly occurs in large draft breeds such as Belgians, Shires, Friesians, and Gypsies etc. More research on CPL is needed to find out exactly how it works.